Internet Engineering Task Force (IETF)                        Q. Wu, Ed.
Request for Comments: 8299                                        Huawei
Obsoletes: 8049                                             S. Litkowski
Category: Standards Track                                         Orange
ISSN: 2070-1721                                              L. Tomotaki
                                                                Verizon
                                                               K. Ogaki
                                                       KDDI Corporation
                                                           January 2018


              YANG Data Model for L3VPN Service Delivery

Abstract

  This document defines a YANG data model that can be used for
  communication between customers and network operators and to deliver
  a Layer 3 provider-provisioned VPN service.  This document is limited
  to BGP PE-based VPNs as described in RFCs 4026, 4110, and 4364.  This
  model is intended to be instantiated at the management system to
  deliver the overall service.  It is not a configuration model to be
  used directly on network elements.  This model provides an abstracted
  view of the Layer 3 IP VPN service configuration components.  It will
  be up to the management system to take this model as input and use
  specific configuration models to configure the different network
  elements to deliver the service.  How the configuration of network
  elements is done is out of scope for this document.

  This document obsoletes RFC 8049; it replaces the unimplementable
  module in that RFC with a new module with the same name that is not
  backward compatible.  The changes are a series of small fixes to the
  YANG module and some clarifications to the text.

Status of This Memo

  This is an Internet Standards Track document.

  This document is a product of the Internet Engineering Task Force
  (IETF).  It represents the consensus of the IETF community.  It has
  received public review and has been approved for publication by the
  Internet Engineering Steering Group (IESG).  Further information on
  Internet Standards is available in Section 2 of RFC 7841.

  Information about the current status of this document, any errata,
  and how to provide feedback on it may be obtained at
  https://www.rfc-editor.org/info/rfc8299.





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RFC 8299       YANG Data Model for L3VPN Service Delivery   January 2018


Copyright Notice

  Copyright (c) 2018 IETF Trust and the persons identified as the
  document authors.  All rights reserved.

  This document is subject to BCP 78 and the IETF Trust's Legal
  Provisions Relating to IETF Documents
  (https://trustee.ietf.org/license-info) in effect on the date of
  publication of this document.  Please review these documents
  carefully, as they describe your rights and restrictions with respect
  to this document.  Code Components extracted from this document must
  include Simplified BSD License text as described in Section 4.e of
  the Trust Legal Provisions and are provided without warranty as
  described in the Simplified BSD License.

Table of Contents

  1. Introduction ....................................................4
     1.1. Terminology ................................................4
     1.2. Requirements Language ......................................5
     1.3. Tree Diagrams ..............................................5
     1.4. Summary of Changes from RFC 8049 ...........................5
          1.4.1. Implementation Issues with RFC 8049 .................7
          1.4.2. Impact Assessment ...................................7
  2. Acronyms ........................................................8
  3. Definitions ....................................................10
  4. Layer 3 IP VPN Service Model ...................................10
  5. Service Data Model Usage .......................................11
  6. Design of the Data Model .......................................12
     6.1. Features and Augmentation .................................22
     6.2. VPN Service Overview ......................................22
          6.2.1. VPN Service Topology ...............................23
          6.2.2. Cloud Access .......................................26
          6.2.3. Multicast Service ..................................29
          6.2.4. Extranet VPNs ......................................30
     6.3. Site Overview .............................................32
          6.3.1. Devices and Locations ..............................33
          6.3.2. Site Network Accesses ..............................34
     6.4. Site Role .................................................36
     6.5. Site Belonging to Multiple VPNs ...........................37
          6.5.1. Site VPN Flavor ....................................37
          6.5.2. Attaching a Site to a VPN ..........................41









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     6.6. Deciding Where to Connect the Site ........................47
          6.6.1. Constraint: Device .................................48
          6.6.2. Constraint/Parameter: Site Location ................48
          6.6.3. Constraint/Parameter: Access Type ..................49
          6.6.4. Constraint: Access Diversity .......................50
          6.6.5. Infeasible Access Placement ........................59
          6.6.6. Examples of Access Placement .......................60
          6.6.7. Route Distinguisher and VRF Allocation .............80
     6.7. Site Network Access Availability ..........................81
     6.8. Traffic Protection ........................................82
     6.9. Security ..................................................83
          6.9.1. Authentication .....................................83
          6.9.2. Encryption .........................................84
     6.10. Management ...............................................85
     6.11. Routing Protocols ........................................86
          6.11.1. Handling of Dual Stack ............................87
          6.11.2. LAN Directly Connected to SP Network ..............88
          6.11.3. LAN Directly Connected to SP Network with
                  Redundancy ........................................89
          6.11.4. Static Routing ....................................89
          6.11.5. RIP Routing .......................................89
          6.11.6. OSPF Routing ......................................90
          6.11.7. BGP Routing .......................................92
     6.12. Service ..................................................93
          6.12.1. Bandwidth .........................................94
          6.12.2. MTU ...............................................94
          6.12.3. QoS ...............................................94
          6.12.4. Multicast ........................................103
     6.13. Enhanced VPN Features ...................................104
          6.13.1. Carriers' Carriers ...............................104
     6.14. External ID References ..................................105
     6.15. Defining NNIs ...........................................105
          6.15.1. Defining an NNI with the Option A Flavor .........107
          6.15.2. Defining an NNI with the Option B Flavor .........111
          6.15.3. Defining an NNI with the Option C Flavor .........113
  7. Service Model Usage Example ...................................114
  8. Interaction with Other YANG Models ............................120
  9. YANG Module ...................................................125
  10. Security Considerations ......................................184
  11. IANA Considerations ..........................................185
  12. References ...................................................185
     12.1. Normative References ....................................185
     12.2. Informative References ..................................187
  Acknowledgements .................................................188
  Contributors .....................................................188
  Authors' Addresses ...............................................188





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1.  Introduction

  This document defines a Layer 3 VPN service data model written in
  YANG.  The model defines service configuration elements that can be
  used in communication protocols between customers and network
  operators.  Those elements can also be used as input to automated
  control and configuration applications.

  This document obsoletes [RFC8049]; it creates a new module with the
  same name as the module defined in [RFC8049].  The changes from
  [RFC8049] are listed in full in Section 1.4.  They are small in
  scope, but include fixes to the module to make it possible to
  implement.

  The YANG module described in [RFC8049] cannot be implemented because
  of issues around the use of XPATH.  These issues are explained in
  Section 1.4.1.

  Section 11 of [RFC7950] describes when it is permissible to reuse a
  module name.  Section 1.4.2 provides an impact assessment in this
  context.

1.1.  Terminology

  The following terms are defined in [RFC6241]  and are not redefined
  here:

  o  client

  o  configuration data

  o  server

  o  state data

  The following terms are defined in [RFC7950] and are not redefined
  here:

  o  augment

  o  data model

  o  data node

  The terminology for describing YANG data models is found in
  [RFC7950].





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  This document presents some configuration examples using XML
  representation.

1.2.  Requirements Language

  The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
  "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
  "OPTIONAL" in this document are to be interpreted as described in BCP
  14 [RFC2119] [RFC8174] when, and only when, they appear in all
  capitals, as shown here.

1.3.  Tree Diagrams

  A simplified graphical representation of the data model is presented
  in Section 6.

  The meanings of the symbols in these diagrams are as follows:

  o  Brackets "[" and "]" enclose list keys.

  o  Curly braces "{" and "}" contain names of optional features that
     make the corresponding node conditional.

  o  Abbreviations before data node names: "rw" means configuration
     data (read-write), and "ro" means state data (read-only).

  o  Symbols after data node names: "?" means an optional node, and "*"
     denotes a "list" or "leaf-list".

  o  Parentheses enclose choice and case nodes, and case nodes are also
     marked with a colon (":").

  o  Ellipsis ("...") stands for contents of subtrees that are not
     shown.

1.4.  Summary of Changes from RFC 8049

  This document revises and obsoletes L3VPN Service Model [RFC8049],
  drawing on insights gained from L3VPN Service Model deployments and
  on feedback from the community.  The major changes are as follows:

  o  Change type from 16-bit integer to string for the leaf id under
     "qos-classification-policy" container.

  o  Stick to using ordered-by user and remove inefficiency to map
     service model sequence number to device model sequence number.





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RFC 8299       YANG Data Model for L3VPN Service Delivery   January 2018


  o  Remove mandating the use of deviations and add "if-feature target-
     sites" under the leaf-list target-sites in Section 6.12.2.1 of
     [RFC8049].

  o  Change in keywords from [RFC2119] and [RFC8174] on operation of
     the management system in the third paragraph of Section 6.6,
     Section 6.6.5, and Section 7.

  o  Fix incomplete description statements.

  o  Add YANG statement to check that Stateless Address
     Autoconfiguration (SLAAC) parameters are used only for IPv6.

  o  Fix strange wording in Section 6.11.7.

  o  Change the use of the absolute paths to the use of relative paths
     in the "must" statement or "path" statement for vpn-policy-id leaf
     node, management container, location leaf node, devices container,
     location case, location-reference leaf, device case, device-
     reference leaf to make configuration is only applicable to the
     current sites.

  o  Change "must" statement to "when" statement for management
     container device container.

  o  Fix optional parameter issues by adding a default or description
     for others or make some of them mandatory.

  o  Define new grouping vpn-profile-cfg for all the identifiers
     provided by SP to the customer.  The identifiers include cloud-
     identifier, std-qos-profile, OAM profile-name, and provider-
     profile for encryption.

  o  Add in the XPATH string representation of identityrefs and remove
     unqualified name.  Change from YANG 1.0 Support to YANG 1.1
     Support.

  o  Remove "when" statement from leaf nat44-customer-address.

  o  Fixed broken example and Add mandatory element in the examples.

  o  Remove redundant parameters in the cloud access.

  o  Specify provider address and a list of start-end addresses from
     provider address for DHCP case.

  o  Add a few text to clarify what the site is in Section 6.3.




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  o  Add multi-filter and multiVPN per entry support for VPN policy.

  o  Modify description for svc-input-bandwidth leaf and svc-output-
     bandwidth leaf to make it consistent with the text in
     Section 6.12.1.

  o  Clarify the rational of the model in the Section 5.

  o  Add text to clarify the way to achieve Per-VPN QoS policy.

1.4.1.  Implementation Issues with RFC 8049

  [RFC8049] made an initial attempt to define a YANG data model
  forL3VPN services.  After it was published it was discovered that,
  while the YANG compiled it was broken from an implementation
  perspective.  That is, it was impossible to build a functional
  implementation of the module.

  Section 1.4 provides a full list of the changes since [RFC8049].
  Some of these changes remove ambiguities from the documented YANG,
  while other changes fix the implementation issues.

  1.  Several uses of 'must' expressions in the module were broken
      badly enough that the module was not usable in the form it was
      published.  While some compilers and YANG checkers found no
      issues (most YANG tools do not attempt to parse these
      expressions), other tools that really understand the XPATH in the
      expressions refused to compile them.

      The changes needed to fix these expressions were small and local.

  2.  The second issue relates to how Access Control List (ACL) rules
      were sorted.  In [RFC8049] the English language text and the text
      in the YANG definition contradicted each other.  Furthermore, the
      model used classic ACL rule numbering notation for something that
      was semantically very different (ordered-by user) in the YANG
      thus creating the potential for misunderstanding.

  3.  Further to point 2, the ACL modeling in [RFC8049] was
      incompatible with work going on in other IETF documents such as
      [ACL-YANG].

1.4.2.  Impact Assessment

  When changing the content of a YANG module, care must be taken to
  ensure that there are no interoperability issues caused by a failure
  to enable backward compatibility.




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  Section 11 of [RFC7950] clearly describes the circumstances under
  which it is not acceptable to maintain a module name.

     ...changes to published modules are not allowed if they have any
     potential to cause interoperability problems between a client
     using an original specification and a server using an updated
     specification.

  The module defined in this document is not backward compatible with
  that defined in [RFC8049], but it is important to understand that
  there is no possibility of an interoperability issue between the
  module defined in this document and that presented in [RFC8049]
  because that module could not be implemented for the reasons
  described in Section 1.4.1.  Thus, noting the rules set out in
  [RFC7950], it was decided to retain the module name in this document.

2.  Acronyms

  AAA: Authentication, Authorization, and Accounting.

  ACL: Access Control List.

  ADSL: Asymmetric DSL.

  AH: Authentication Header.

  AS: Autonomous System.

  ASBR: Autonomous System Border Router.

  ASM: Any-Source Multicast.

  BAS: Broadband Access Switch.

  BFD: Bidirectional Forwarding Detection.

  BGP: Border Gateway Protocol.

  BSR: Bootstrap Router.

  CE: Customer Edge.

  CLI: Command Line Interface.

  CsC: Carriers' Carriers.

  CSP: Cloud Service Provider.




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RFC 8299       YANG Data Model for L3VPN Service Delivery   January 2018


  DHCP: Dynamic Host Configuration Protocol.

  DSLAM: Digital Subscriber Line Access Multiplexer.

  ESP: Encapsulating Security Payload.

  GRE: Generic Routing Encapsulation.

  IGMP: Internet Group Management Protocol.

  LAN: Local Area Network.

  MLD: Multicast Listener Discovery.

  MTU: Maximum Transmission Unit.

  NAT: Network Address Translation.

  NETCONF: Network Configuration Protocol.

  NNI: Network-to-Network Interface.

  OAM: Operations, Administration, and Maintenance.

  OSPF: Open Shortest Path First.

  OSS: Operations Support System.

  PE: Provider Edge.

  PIM: Protocol Independent Multicast.

  POP: Point of Presence.

  QoS: Quality of Service.

  RD: Route Distinguisher.

  RIP: Routing Information Protocol.

  RP: Rendezvous Point.

  RT: Route Target.

  SFTP: Secure FTP.

  SLA: Service Level Agreement.




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  SLAAC: Stateless Address Autoconfiguration.

  SP: Service Provider.

  SPT: Shortest Path Tree.

  SSM: Source-Specific Multicast.

  VM: Virtual Machine.

  VPN: Virtual Private Network.

  VRF: VPN Routing and Forwarding.

  VRRP: Virtual Router Redundancy Protocol.

3.  Definitions

  Customer Edge (CE) Device: A CE is equipment dedicated to a
  particular customer; it is directly connected (at Layer 3) to one or
  more PE devices via attachment circuits.  A CE is usually located at
  the customer premises and is usually dedicated to a single VPN,
  although it may support multiple VPNs if each one has separate
  attachment circuits.

  Provider Edge (PE) Device: A PE is equipment managed by the SP; it
  can support multiple VPNs for different customers and is directly
  connected (at Layer 3) to one or more CE devices via attachment
  circuits.  A PE is usually located at an SP point of presence (POP)
  and is managed by the SP.

  PE-Based VPNs: The PE devices know that certain traffic is VPN
  traffic.  They forward the traffic (through tunnels) based on the
  destination IP address of the packet and, optionally, based on other
  information in the IP header of the packet.  The PE devices are
  themselves the tunnel endpoints.  The tunnels may make use of various
  encapsulations to send traffic over the SP network (such as, but not
  restricted to, GRE, IP-in-IP, IPsec, or MPLS tunnels).

4.  Layer 3 IP VPN Service Model

  A Layer 3 IP VPN service is a collection of sites that are authorized
  to exchange traffic between each other over a shared IP
  infrastructure.  This Layer 3 VPN service model aims at providing a
  common understanding of how the corresponding IP VPN service is to be
  deployed over the shared infrastructure.  This service model is
  limited to BGP PE-based VPNs as described in [RFC4026], [RFC4110],
  and [RFC4364].



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RFC 8299       YANG Data Model for L3VPN Service Delivery   January 2018


5.  Service Data Model Usage

                  l3vpn-svc |
                    Model   |
                            |
                     +------------------+         +-----+
                     |   Orchestration  | < --- > | OSS |
                     +------------------+         +-----+
                        |            |
                +----------------+   |
                | Config manager |   |
                +----------------+   |
                        |            |
                        | NETCONF/CLI ...
                        |            |
          +------------------------------------------------+
                               Network

                             +++++++
                             + AAA +
                             +++++++

     ++++++++   Bearer    ++++++++           ++++++++      ++++++++
     + CE A + ----------- + PE A +           + PE B + ---- + CE B +
     ++++++++  Connection ++++++++           ++++++++      ++++++++

                Site A                               Site B

  The idea of the L3 IP VPN service model is to propose an abstracted
  interface between customers and network operators to manage
  configuration of components of an L3VPN service.  The model is
  intended to be used in a mode where the network operator's system is
  the server and the customer's system is the client.  A typical
  scenario would be to use this model as an input for an orchestration
  layer that will be responsible for translating it to an orchestrated
  configuration of network elements that will be part of the service.
  The network elements can be routers but can also be servers (like
  AAA); the network's configuration is not limited to these examples.
  The configuration of network elements can be done via the CLI,
  NETCONF/RESTCONF [RFC6241] [RFC8040] coupled with YANG data models of
  a specific configuration (BGP, VRF, BFD, etc.), or some other
  technique, as preferred by the operator.

  The usage of this service model is not limited to this example; it
  can be used by any component of the management system but not
  directly by network elements.





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RFC 8299       YANG Data Model for L3VPN Service Delivery   January 2018


6.  Design of the Data Model

  The YANG module is divided into two main containers: "vpn-services"
  and "sites".

  The "vpn-service" list under the vpn-services container defines
  global parameters for the VPN service for a specific customer.

  A "site" is composed of at least one "site-network-access" and, in
  the case of multihoming, may have multiple site-network-access
  points.  The site-network-access attachment is done through a
  "bearer" with an "ip-connection" on top.  The bearer refers to
  properties of the attachment that are below Layer 3, while the
  connection refers to properties oriented to the Layer 3 protocol.
  The bearer may be allocated dynamically by the SP, and the customer
  may provide some constraints or parameters to drive the placement of
  the access.

  Authorization of traffic exchange is done through what we call a VPN
  policy or VPN service topology defining routing exchange rules
  between sites.

  The figure below describes the overall structure of the YANG module:

module: ietf-l3vpn-svc
   +--rw l3vpn-svc
      +--rw vpn-profiles
      |  +--rw valid-provider-identifiers
      |     +--rw cloud-identifier* [id] {cloud-access}?
      |     |  +--rw id    string
      |     +--rw encryption-profile-identifier* [id]
      |     |  +--rw id    string
      |     +--rw qos-profile-identifier* [id]
      |     |  +--rw id    string
      |     +--rw bfd-profile-identifier* [id]
      |        +--rw id    string
      +--rw vpn-services
      |  +--rw vpn-service* [vpn-id]
      |     +--rw vpn-id                  svc-id
      |     +--rw customer-name?          string
      |     +--rw vpn-service-topology?   identityref
      |     +--rw cloud-accesses {cloud-access}?
      |     |  +--rw cloud-access* [cloud-identifier]
      |     |     +--rw cloud-identifier       leafref
      |     |     +--rw (list-flavor)?
      |     |     |  +--:(permit-any)
      |     |     |  |  +--rw permit-any?            empty
      |     |     |  +--:(deny-any-except)



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RFC 8299       YANG Data Model for L3VPN Service Delivery   January 2018


      |     |     |  |  +--rw permit-site*
      |     |     |  |          -> /l3vpn-svc/sites/site/site-id
      |     |     |  +--:(permit-any-except)
      |     |     |     +--rw deny-site*
      |     |     |             -> /l3vpn-svc/sites/site/site-id
      |     |     +--rw address-translation
      |     |        +--rw nat44
      |     |           +--rw enabled?                  boolean
      |     |           +--rw nat44-customer-address?
      |     |                   inet:ipv4-address
      |     +--rw multicast {multicast}?
      |     |  +--rw enabled?                 boolean
      |     |  +--rw customer-tree-flavors
      |     |  |  +--rw tree-flavor*   identityref
      |     |  +--rw rp
      |     |     +--rw rp-group-mappings
      |     |     |  +--rw rp-group-mapping* [id]
      |     |     |     +--rw id                  uint16
      |     |     |     +--rw provider-managed
      |     |     |     |  +--rw enabled?                    boolean
      |     |     |     |  +--rw rp-redundancy?              boolean
      |     |     |     |  +--rw optimal-traffic-delivery?   boolean
      |     |     |     +--rw rp-address          inet:ip-address
      |     |     |     +--rw groups
      |     |     |        +--rw group* [id]
      |     |     |           +--rw id               uint16
      |     |     |           +--rw (group-format)
      |     |     |              +--:(singleaddress)
      |     |     |              |  +--rw group-address?
      |     |     |              |          inet:ip-address
      |     |     |              +--:(startend)
      |     |     |                 +--rw group-start?
      |     |     |                 |       inet:ip-address
      |     |     |                 +--rw group-end?
      |     |     |                         inet:ip-address
      |     |     +--rw rp-discovery
      |     |        +--rw rp-discovery-type?   identityref
      |     |        +--rw bsr-candidates
      |     |           +--rw bsr-candidate-address*   inet:ip-address
      |     +--rw carrierscarrier?        boolean {carrierscarrier}?
      |     +--rw extranet-vpns {extranet-vpn}?
      |        +--rw extranet-vpn* [vpn-id]
      |           +--rw vpn-id              svc-id
      |           +--rw local-sites-role?   identityref
      +--rw sites
         +--rw site* [site-id]
            +--rw site-id                  svc-id
            +--rw requested-site-start?    yang:date-and-time



Wu, et al.                   Standards Track                   [Page 13]

RFC 8299       YANG Data Model for L3VPN Service Delivery   January 2018


            +--rw requested-site-stop?     yang:date-and-time
            +--rw locations
            |  +--rw location* [location-id]
            |     +--rw location-id     svc-id
            |     +--rw address?        string
            |     +--rw postal-code?    string
            |     +--rw state?          string
            |     +--rw city?           string
            |     +--rw country-code?   string
            +--rw devices
            |  +--rw device* [device-id]
            |     +--rw device-id     svc-id
            |     +--rw location
            |     |       -> ../../../locations/location/location-id
            |     +--rw management
            |        +--rw address-family?   address-family
            |        +--rw address           inet:ip-address
            +--rw site-diversity {site-diversity}?
            |  +--rw groups
            |     +--rw group* [group-id]
            |        +--rw group-id    string
            +--rw management
            |  +--rw type    identityref
            +--rw vpn-policies
            |  +--rw vpn-policy* [vpn-policy-id]
            |     +--rw vpn-policy-id    svc-id
            |     +--rw entries* [id]
            |        +--rw id         svc-id
            |        +--rw filters
            |        |  +--rw filter* [type]
            |        |     +--rw type               identityref
            |        |     +--rw lan-tag*           string
            |        |     |       {lan-tag}?
            |        |     +--rw ipv4-lan-prefix*   inet:ipv4-prefix
            |        |     |       {ipv4}?
            |        |     +--rw ipv6-lan-prefix*   inet:ipv6-prefix
            |        |             {ipv6}?
            |        +--rw vpn* [vpn-id]
            |           +--rw vpn-id       leafref
            |           +--rw site-role?   identityref
            +--rw site-vpn-flavor?         identityref
            +--rw maximum-routes
            |  +--rw address-family* [af]
            |     +--rw af                address-family
            |     +--rw maximum-routes?   uint32
            +--rw security
            |  +--rw authentication
            |  +--rw encryption {encryption}?



Wu, et al.                   Standards Track                   [Page 14]

RFC 8299       YANG Data Model for L3VPN Service Delivery   January 2018


            |     +--rw enabled?              boolean
            |     +--rw layer?                enumeration
            |     +--rw encryption-profile
            |        +--rw (profile)?
            |           +--:(provider-profile)
            |           |  +--rw profile-name?    leafref
            |           +--:(customer-profile)
            |              +--rw algorithm?       string
            |              +--rw (key-type)?
            |                 +--:(psk)
            |                    +--rw preshared-key?   string
            +--rw service
            |  +--rw qos {qos}?
            |  |  +--rw qos-classification-policy
            |  |  |  +--rw rule* [id]
            |  |  |     +--rw id                   string
            |  |  |     +--rw (match-type)?
            |  |  |     |  +--:(match-flow)
            |  |  |     |  |  +--rw match-flow
            |  |  |     |  |     +--rw dscp?                inet:dscp
            |  |  |     |  |     +--rw dot1p?               uint8
            |  |  |     |  |     +--rw ipv4-src-prefix?
            |  |  |     |  |     |       inet:ipv4-prefix
            |  |  |     |  |     +--rw ipv6-src-prefix?
            |  |  |     |  |     |       inet:ipv6-prefix
            |  |  |     |  |     +--rw ipv4-dst-prefix?
            |  |  |     |  |     |       inet:ipv4-prefix
            |  |  |     |  |     +--rw ipv6-dst-prefix?
            |  |  |     |  |     |       inet:ipv6-prefix
            |  |  |     |  |     +--rw l4-src-port?
            |  |  |     |  |     |       inet:port-number
            |  |  |     |  |     +--rw target-sites*        svc-id
            |  |  |     |  |     |       {target-sites}?
            |  |  |     |  |     +--rw l4-src-port-range
            |  |  |     |  |     |  +--rw lower-port?  inet:port-number
            |  |  |     |  |     |  +--rw upper-port?  inet:port-number
            |  |  |     |  |     +--rw l4-dst-port?
            |  |  |     |  |     |       inet:port-number
            |  |  |     |  |     +--rw l4-dst-port-range
            |  |  |     |  |     |  +--rw lower-port?  inet:port-number
            |  |  |     |  |     |  +--rw upper-port?  inet:port-number
            |  |  |     |  |     +--rw protocol-field?      union
            |  |  |     |  +--:(match-application)
            |  |  |     |     +--rw match-application?   identityref
            |  |  |     +--rw target-class-id?     string
            |  |  +--rw qos-profile
            |  |     +--rw (qos-profile)?
            |  |        +--:(standard)



Wu, et al.                   Standards Track                   [Page 15]

RFC 8299       YANG Data Model for L3VPN Service Delivery   January 2018


            |  |        |  +--rw profile?   leafref
            |  |        +--:(custom)
            |  |           +--rw classes {qos-custom}?
            |  |              +--rw class* [class-id]
            |  |                 +--rw class-id      string
            |  |                 +--rw direction?    identityref
            |  |                 +--rw rate-limit?   decimal64
            |  |                 +--rw latency
            |  |                 |  +--rw (flavor)?
            |  |                 |     +--:(lowest)
            |  |                 |     |  +--rw use-lowest-latency?
            |  |                 |     |          empty
            |  |                 |     +--:(boundary)
            |  |                 |        +--rw latency-boundary?
            |  |                 |                uint16
            |  |                 +--rw jitter
            |  |                 |  +--rw (flavor)?
            |  |                 |     +--:(lowest)
            |  |                 |     |  +--rw use-lowest-jitter?
            |  |                 |     |          empty
            |  |                 |     +--:(boundary)
            |  |                 |        +--rw latency-boundary?
            |  |                 |                uint32
            |  |                 +--rw bandwidth
            |  |                    +--rw guaranteed-bw-percent
            |  |                    |       decimal64
            |  |                    +--rw end-to-end?            empty
            |  +--rw carrierscarrier {carrierscarrier}?
            |  |  +--rw signalling-type?   enumeration
            |  +--rw multicast {multicast}?
            |     +--rw multicast-site-type?        enumeration
            |     +--rw multicast-address-family
            |     |  +--rw ipv4?   boolean {ipv4}?
            |     |  +--rw ipv6?   boolean {ipv6}?
            |     +--rw protocol-type?              enumeration
            +--rw traffic-protection {fast-reroute}?
            |  +--rw enabled?   boolean
            +--rw routing-protocols
            |  +--rw routing-protocol* [type]
            |     +--rw type      identityref
            |     +--rw ospf {rtg-ospf}?
            |     |  +--rw address-family*   address-family
            |     |  +--rw area-address      yang:dotted-quad
            |     |  +--rw metric?           uint16
            |     |  +--rw sham-links {rtg-ospf-sham-link}?
            |     |     +--rw sham-link* [target-site]
            |     |        +--rw target-site    svc-id
            |     |        +--rw metric?        uint16



Wu, et al.                   Standards Track                   [Page 16]

RFC 8299       YANG Data Model for L3VPN Service Delivery   January 2018


            |     +--rw bgp {rtg-bgp}?
            |     |  +--rw autonomous-system    uint32
            |     |  +--rw address-family*      address-family
            |     +--rw static
            |     |  +--rw cascaded-lan-prefixes
            |     |     +--rw ipv4-lan-prefixes* [lan next-hop]
            |     |     |       {ipv4}?
            |     |     |  +--rw lan         inet:ipv4-prefix
            |     |     |  +--rw lan-tag?    string
            |     |     |  +--rw next-hop    inet:ipv4-address
            |     |     +--rw ipv6-lan-prefixes* [lan next-hop]
            |     |             {ipv6}?
            |     |        +--rw lan         inet:ipv6-prefix
            |     |        +--rw lan-tag?    string
            |     |        +--rw next-hop    inet:ipv6-address
            |     +--rw rip {rtg-rip}?
            |     |  +--rw address-family*   address-family
            |     +--rw vrrp {rtg-vrrp}?
            |        +--rw address-family*   address-family
            +--ro actual-site-start?       yang:date-and-time
            +--ro actual-site-stop?        yang:date-and-time
            +--rw site-network-accesses
               +--rw site-network-access* [site-network-access-id]
                  +--rw site-network-access-id      svc-id
                  +--rw site-network-access-type?   identityref
                  +--rw (location-flavor)
                  |  +--:(location)
                  |  |  +--rw location-reference?         leafref
                  |  +--:(device)
                  |     +--rw device-reference?
                  |             -> ../../../devices/device/device-id
                  +--rw access-diversity {site-diversity}?
                  |  +--rw groups
                  |  |  +--rw group* [group-id]
                  |  |     +--rw group-id    string
                  |  +--rw constraints
                  |     +--rw constraint* [constraint-type]
                  |        +--rw constraint-type    identityref
                  |        +--rw target
                  |           +--rw (target-flavor)?
                  |              +--:(id)
                  |              |  +--rw group* [group-id]
                  |              |     +--rw group-id    string
                  |              +--:(all-accesses)
                  |              |  +--rw all-other-accesses?   empty
                  |              +--:(all-groups)
                  |                 +--rw all-other-groups?     empty
                  +--rw bearer



Wu, et al.                   Standards Track                   [Page 17]

RFC 8299       YANG Data Model for L3VPN Service Delivery   January 2018


                  |  +--rw requested-type {requested-type}?
                  |  |  +--rw requested-type?   string
                  |  |  +--rw strict?           boolean
                  |  +--rw always-on?          boolean {always-on}?
                  |  +--rw bearer-reference?   string
                  |          {bearer-reference}?
                  +--rw ip-connection
                  |  +--rw ipv4 {ipv4}?
                  |  |  +--rw address-allocation-type?   identityref
                  |  |  +--rw provider-dhcp
                  |  |  |  +--rw provider-address?
                  |  |  |  |       inet:ipv4-address
                  |  |  |  +--rw prefix-length?               uint8
                  |  |  |  +--rw (address-assign)?
                  |  |  |     +--:(number)
                  |  |  |     |  +--rw number-of-dynamic-address?
                  |  |  |     |          uint16
                  |  |  |     +--:(explicit)
                  |  |  |        +--rw customer-addresses
                  |  |  |           +--rw address-group* [group-id]
                  |  |  |              +--rw group-id         string
                  |  |  |              +--rw start-address?
                  |  |  |              |       inet:ipv4-address
                  |  |  |              +--rw end-address?
                  |  |  |                      inet:ipv4-address
                  |  |  +--rw dhcp-relay
                  |  |  |  +--rw provider-address?
                  |  |  |  |       inet:ipv4-address
                  |  |  |  +--rw prefix-length?           uint8
                  |  |  |  +--rw customer-dhcp-servers
                  |  |  |     +--rw server-ip-address*
                  |  |  |             inet:ipv4-address
                  |  |  +--rw addresses
                  |  |     +--rw provider-address?   inet:ipv4-address
                  |  |     +--rw customer-address?   inet:ipv4-address
                  |  |     +--rw prefix-length?      uint8
                  |  +--rw ipv6 {ipv6}?
                  |  |  +--rw address-allocation-type?   identityref
                  |  |  +--rw provider-dhcp
                  |  |  |  +--rw provider-address?
                  |  |  |  |       inet:ipv6-address
                  |  |  |  +--rw prefix-length?               uint8
                  |  |  |  +--rw (address-assign)?
                  |  |  |     +--:(number)
                  |  |  |     |  +--rw number-of-dynamic-address?
                  |  |  |     |          uint16
                  |  |  |     +--:(explicit)
                  |  |  |        +--rw customer-addresses



Wu, et al.                   Standards Track                   [Page 18]

RFC 8299       YANG Data Model for L3VPN Service Delivery   January 2018


                  |  |  |           +--rw address-group* [group-id]
                  |  |  |              +--rw group-id         string
                  |  |  |              +--rw start-address?
                  |  |  |              |       inet:ipv6-address
                  |  |  |              +--rw end-address?
                  |  |  |                      inet:ipv6-address
                  |  |  +--rw dhcp-relay
                  |  |  |  +--rw provider-address?
                  |  |  |  |       inet:ipv6-address
                  |  |  |  +--rw prefix-length?           uint8
                  |  |  |  +--rw customer-dhcp-servers
                  |  |  |     +--rw server-ip-address*
                  |  |  |             inet:ipv6-address
                  |  |  +--rw addresses
                  |  |     +--rw provider-address?   inet:ipv6-address
                  |  |     +--rw customer-address?   inet:ipv6-address
                  |  |     +--rw prefix-length?      uint8
                  |  +--rw oam
                  |     +--rw bfd {bfd}?
                  |        +--rw enabled?        boolean
                  |        +--rw (holdtime)?
                  |           +--:(fixed)
                  |           |  +--rw fixed-value?    uint32
                  |           +--:(profile)
                  |              +--rw profile-name?   leafref
                  +--rw security
                  |  +--rw authentication
                  |  +--rw encryption {encryption}?
                  |     +--rw enabled?              boolean
                  |     +--rw layer?                enumeration
                  |     +--rw encryption-profile
                  |        +--rw (profile)?
                  |           +--:(provider-profile)
                  |           |  +--rw profile-name?    leafref
                  |           +--:(customer-profile)
                  |              +--rw algorithm?       string
                  |              +--rw (key-type)?
                  |                 +--:(psk)
                  |                    +--rw preshared-key?   string
                  +--rw service
                  |  +--rw svc-input-bandwidth     uint64
                  |  +--rw svc-output-bandwidth    uint64
                  |  +--rw svc-mtu                 uint16
                  |  +--rw qos {qos}?
                  |  |  +--rw qos-classification-policy
                  |  |  |  +--rw rule* [id]
                  |  |  |     +--rw id                   string
                  |  |  |     +--rw (match-type)?



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RFC 8299       YANG Data Model for L3VPN Service Delivery   January 2018


                  |  |  |     |  +--:(match-flow)
                  |  |  |     |  |  +--rw match-flow
                  |  |  |     |  |     +--rw dscp?
                  |  |  |     |  |     |       inet:dscp
                  |  |  |     |  |     +--rw dot1p?              uint8
                  |  |  |     |  |     +--rw ipv4-src-prefix?
                  |  |  |     |  |     |       inet:ipv4-prefix
                  |  |  |     |  |     +--rw ipv6-src-prefix?
                  |  |  |     |  |     |       inet:ipv6-prefix
                  |  |  |     |  |     +--rw ipv4-dst-prefix?
                  |  |  |     |  |     |       inet:ipv4-prefix
                  |  |  |     |  |     +--rw ipv6-dst-prefix?
                  |  |  |     |  |     |       inet:ipv6-prefix
                  |  |  |     |  |     +--rw l4-src-port?
                  |  |  |     |  |     |       inet:port-number
                  |  |  |     |  |     +--rw target-sites*      svc-id
                  |  |  |     |  |     |       {target-sites}?
                  |  |  |     |  |     +--rw l4-src-port-range
                  |  |  |     |  |     |  +--rw lower-port?
                  |  |  |     |  |     |  |       inet:port-number
                  |  |  |     |  |     |  +--rw upper-port?
                  |  |  |     |  |     |          inet:port-number
                  |  |  |     |  |     +--rw l4-dst-port?
                  |  |  |     |  |     |       inet:port-number
                  |  |  |     |  |     +--rw l4-dst-port-range
                  |  |  |     |  |     |  +--rw lower-port?
                  |  |  |     |  |     |  |       inet:port-number
                  |  |  |     |  |     |  +--rw upper-port?
                  |  |  |     |  |     |          inet:port-number
                  |  |  |     |  |     +--rw protocol-field?     union
                  |  |  |     |  +--:(match-application)
                  |  |  |     |     +--rw match-application?
                  |  |  |     |             identityref
                  |  |  |     +--rw target-class-id?     string
                  |  |  +--rw qos-profile
                  |  |     +--rw (qos-profile)?
                  |  |        +--:(standard)
                  |  |        |  +--rw profile?   leafref
                  |  |        +--:(custom)
                  |  |           +--rw classes {qos-custom}?
                  |  |              +--rw class* [class-id]
                  |  |                 +--rw class-id      string
                  |  |                 +--rw direction?    identityref
                  |  |                 +--rw rate-limit?   decimal64
                  |  |                 +--rw latency
                  |  |                 |  +-rw (flavor)?
                  |  |                 |    +--:(lowest)
                  |  |                 |    |  +-rw use-lowest-latency?



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                  |  |                 |    |          empty
                  |  |                 |    +--:(boundary)
                  |  |                 |       +-rw latency-boundary?
                  |  |                 |                uint16
                  |  |                 +--rw jitter
                  |  |                 |  +-rw (flavor)?
                  |  |                 |    +--:(lowest)
                  |  |                 |    |  +--rw use-lowest-jitter?
                  |  |                 |    |          empty
                  |  |                 |    +--:(boundary)
                  |  |                 |       +--rw latency-boundary?
                  |  |                 |                uint32
                  |  |                 +--rw bandwidth
                  |  |                    +--rw guaranteed-bw-percent
                  |  |                    |       decimal64
                  |  |                    +--rw end-to-end?
                  |  |                            empty
                  |  +--rw carrierscarrier {carrierscarrier}?
                  |  |  +--rw signalling-type?   enumeration
                  |  +--rw multicast {multicast}?
                  |     +--rw multicast-site-type?        enumeration
                  |     +--rw multicast-address-family
                  |     |  +--rw ipv4?   boolean {ipv4}?
                  |     |  +--rw ipv6?   boolean {ipv6}?
                  |     +--rw protocol-type?              enumeration
                  +--rw routing-protocols
                  |  +--rw routing-protocol* [type]
                  |     +--rw type      identityref
                  |     +--rw ospf {rtg-ospf}?
                  |     |  +--rw address-family*   address-family
                  |     |  +--rw area-address      yang:dotted-quad
                  |     |  +--rw metric?           uint16
                  |     |  +--rw sham-links {rtg-ospf-sham-link}?
                  |     |     +--rw sham-link* [target-site]
                  |     |        +--rw target-site    svc-id
                  |     |        +--rw metric?        uint16
                  |     +--rw bgp {rtg-bgp}?
                  |     |  +--rw autonomous-system    uint32
                  |     |  +--rw address-family*      address-family
                  |     +--rw static
                  |     |  +--rw cascaded-lan-prefixes
                  |     |     +--rw ipv4-lan-prefixes*
                  |     |     |       [lan next-hop] {ipv4}?
                  |     |     |  +--rw lan         inet:ipv4-prefix
                  |     |     |  +--rw lan-tag?    string
                  |     |     |  +--rw next-hop    inet:ipv4-address
                  |     |     +--rw ipv6-lan-prefixes*
                  |     |             [lan next-hop] {ipv6}?



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                  |     |        +--rw lan         inet:ipv6-prefix
                  |     |        +--rw lan-tag?    string
                  |     |        +--rw next-hop    inet:ipv6-address
                  |     +--rw rip {rtg-rip}?
                  |     |  +--rw address-family*   address-family
                  |     +--rw vrrp {rtg-vrrp}?
                  |        +--rw address-family*   address-family
                  +--rw availability
                  |  +--rw access-priority?   uint32
                  +--rw vpn-attachment
                     +--rw (attachment-flavor)
                        +--:(vpn-policy-id)
                        |  +--rw vpn-policy-id?   leafref
                        +--:(vpn-id)
                           +--rw vpn-id?          leafref
                           +--rw site-role?       identityref

6.1.  Features and Augmentation

  The model defined in this document implements many features that
  allow implementations to be modular.  As an example, an
  implementation may support only IPv4 VPNs (IPv4 feature), IPv6 VPNs
  (IPv6 feature), or both (by advertising both features).  The routing
  protocols proposed to the customer may also be enabled through
  features.  This model also defines some features for options that are
  more advanced, such as support for extranet VPNs (Section 6.2.4),
  site diversity (Section 6.6), and QoS (Section 6.12.3).

  In addition, as for any YANG data model, this service model can be
  augmented to implement new behaviors or specific features.  For
  example, this model uses different options for IP address
  assignments; if those options do not fulfill all requirements, new
  options can be added through augmentation.

6.2.  VPN Service Overview

  A vpn-service list item contains generic information about the VPN
  service.  The "vpn-id" provided in the vpn-service list refers to an
  internal reference for this VPN service, while the customer name
  refers to a more-explicit reference to the customer.  This identifier
  is purely internal to the organization responsible for the VPN
  service.









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RFC 8299       YANG Data Model for L3VPN Service Delivery   January 2018


6.2.1.  VPN Service Topology

  The type of VPN service topology is required for configuration.  Our
  proposed model supports any-to-any, Hub and Spoke (where Hubs can
  exchange traffic), and "Hub and Spoke disjoint" (where Hubs cannot
  exchange traffic).  New topologies could be added via augmentation.
  By default, the any-to-any VPN service topology is used.

6.2.1.1.  Route Target Allocation

  A Layer 3 PE-based VPN is built using route targets (RTs) as
  described in [RFC4364].  The management system is expected to
  automatically allocate a set of RTs upon receiving a VPN service
  creation request.  How the management system allocates RTs is out of
  scope for this document, but multiple ways could be envisaged, as
  described below.

                                   Management system
                    <------------------------------------------------->
                                                Request RT
                     +-----------------------+  Topo a2a   +----------+
          RESTCONF   |                       |  ----->     |          |
  User ------------- | Service Orchestration |             | Network  |
          l3vpn-svc  |                       |  <-----     |   OSS    |
            Model    +-----------------------+   Response  +----------+
                                                 RT1, RT2

  In the example above, a service orchestration, owning the
  instantiation of this service model, requests RTs to the network OSS.
  Based on the requested VPN service topology, the network OSS replies
  with one or multiple RTs.  The interface between this service
  orchestration and the network OSS is out of scope for this document.

                               +---------------------------+
                    RESTCONF   |                           |
            User ------------- |   Service Orchestration   |
                    l3vpn-svc  |                           |
                      Model    |                           |
                               |  RT pool: 10:1->10:10000  |
                               |  RT pool: 20:50->20:5000  |
                               +---------------------------+

  In the example above, a service orchestration, owning the
  instantiation of this service model, owns one or more pools of RTs
  (specified by the SP) that can be allocated.  Based on the requested
  VPN service topology, it will allocate one or multiple RTs from the
  pool.




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  The mechanisms shown above are just examples and should not be
  considered an exhaustive list of solutions.

6.2.1.2.  Any-to-Any

     +------------------------------------------------------------+
     |  VPN1_Site1 ------ PE1               PE2 ------ VPN1_Site2 |
     |                                                            |
     |  VPN1_Site3 ------ PE3               PE4 ------ VPN1_Site4 |
     +------------------------------------------------------------+

                     Any-to-Any VPN Service Topology

  In the any-to-any VPN service topology, all VPN sites can communicate
  with each other without any restrictions.  The management system that
  receives an any-to-any IP VPN service request through this model is
  expected to assign and then configure the VRF and RTs on the
  appropriate PEs.  In the any-to-any case, a single RT is generally
  required, and every VRF imports and exports this RT.

6.2.1.3.  Hub and Spoke

     +-------------------------------------------------------------+
     |   Hub_Site1 ------ PE1               PE2 ------ Spoke_Site1 |
     |                          +----------------------------------+
     |                          |
     |                          +----------------------------------+
     |   Hub_Site2 ------ PE3               PE4 ------ Spoke_Site2 |
     +-------------------------------------------------------------+

                     Hub-and-Spoke VPN Service Topology

  In the Hub-and-Spoke VPN service topology, all Spoke sites can
  communicate only with Hub sites but not with each other, and Hubs can
  also communicate with each other.  The management system that owns an
  any-to-any IP VPN service request through this model is expected to
  assign and then configure the VRF and RTs on the appropriate PEs.  In
  the Hub-and-Spoke case, two RTs are generally required (one RT for
  Hub routes and one RT for Spoke routes).  A Hub VRF that connects Hub
  sites will export Hub routes with the Hub RT and will import Spoke
  routes through the Spoke RT.  It will also import the Hub RT to allow
  Hub-to-Hub communication.  A Spoke VRF that connects Spoke sites will
  export Spoke routes with the Spoke RT and will import Hub routes
  through the Hub RT.







Wu, et al.                   Standards Track                   [Page 24]

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  The management system MUST take into account constraints on Hub-and-
  Spoke connections.  For example, if a management system decides to
  mesh a Spoke site and a Hub site on the same PE, it needs to mesh
  connections in different VRFs, as shown in the figure below.

                   Hub_Site ------- (VRF_Hub)  PE1
                                              (VRF_Spoke)
                                                /  |
                Spoke_Site1 -------------------+   |
                                                   |
                Spoke_Site2 -----------------------+


6.2.1.4.  Hub and Spoke Disjoint

     +-------------------------------------------------------------+
     |   Hub_Site1 ------ PE1               PE2 ------ Spoke_Site1 |
     +--------------------------+  +-------------------------------+
                                |  |
     +--------------------------+  +-------------------------------+
     |   Hub_Site2 ------ PE3               PE4 ------ Spoke_Site2 |
     +-------------------------------------------------------------+

               Hub and Spoke Disjoint VPN Service Topology

  In the Hub and Spoke disjoint VPN service topology, all Spoke sites
  can communicate only with Hub sites but not with each other, and Hubs
  cannot communicate with each other.  The management system that owns
  an any-to-any IP VPN service request through this model is expected
  to assign and then configure the VRF and RTs on the appropriate PEs.
  In the Hub-and-Spoke case, two RTs are required (one RT for Hub
  routes and one RT for Spoke routes).  A Hub VRF that connects Hub
  sites will export Hub routes with the Hub RT and will import Spoke
  routes through the Spoke RT.  A Spoke VRF that connects Spoke sites
  will export Spoke routes with the Spoke RT and will import Hub routes
  through the Hub RT.

  The management system MUST take into account constraints on Hub-and-
  Spoke connections, as in the previous case.

  Hub and Spoke disjoint can also be seen as multiple Hub-and-Spoke
  VPNs (one per Hub) that share a common set of Spoke sites.









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RFC 8299       YANG Data Model for L3VPN Service Delivery   January 2018


6.2.2.  Cloud Access

  The proposed model provides cloud access configuration via the
  "cloud-accesses" container.  The usage of cloud-access is targeted
  for the public cloud.  An Internet access can also be considered a
  public cloud access service.  The cloud-accesses container provides
  parameters for network address translation and authorization rules.

  A private cloud access may be addressed through NNIs, as described in
  Section 6.15.

  A cloud identifier is used to reference the target service.  This
  identifier is local to each administration.

  The model allows for source address translation before accessing the
  cloud.  IPv4-to-IPv4 address translation (NAT44) is the only
  supported option, but other options can be added through
  augmentation.  If IP source address translation is required to access
  the cloud, the "enabled" leaf MUST be set to true in the "nat44"
  container.  An IP address may be provided in the "customer-address"
  leaf if the customer is providing the IP address to be used for the
  cloud access.  If the SP is providing this address, "customer-
  address" is not necessary, as it can be picked from a pool of SPs.

  By default, all sites in the IP VPN MUST be authorized to access the
  cloud.  If restrictions are required, a user MAY configure the
  "permit-site" or "deny-site" leaf-list.  The permit-site leaf-list
  defines the list of sites authorized for cloud access.  The deny-site
  leaf-list defines the list of sites denied for cloud access.  The
  model supports both "deny-any-except" and "permit-any-except"
  authorization.

  How the restrictions will be configured on network elements is out of
  scope for this document.

















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                      IP VPN
            ++++++++++++++++++++++++++++++++     ++++++++++++
            +             Site 3           + --- +  Cloud 1 +
            + Site 1                       +     ++++++++++++
            +                              +
            + Site 2                       + --- ++++++++++++
            +                              +     + Internet +
            +            Site 4            +     ++++++++++++
            ++++++++++++++++++++++++++++++++
                         |
                    +++++++++++
                    + Cloud 2 +
                    +++++++++++

  In the example above, we configure the global VPN to access the
  Internet by creating a cloud-access pointing to the cloud identifier
  for the Internet service.  No authorized sites will be configured, as
  all sites are required to access the Internet.  The "address-
  translation/nat44/enabled" leaf will be set to true.

     <?xml version="1.0"?>
     <l3vpn-svc xmlns="urn:ietf:params:xml:ns:yang:ietf-l3vpn-svc">
       <vpn-services>
         <vpn-service>
           <vpn-id>123456487</vpn-id>
           <cloud-accesses>
             <cloud-access>
               <cloud-identifier>INTERNET</cloud-identifier>
               <address-translation>
                 <nat44>
                   <enabled>true</enabled>
                 </nat44>
               </address-translation>
             </cloud-access>
           </cloud-accesses>
         </vpn-service>
       </vpn-services>
     </l3vpn-svc>













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  If Site 1 and Site 2 require access to Cloud 1, a new cloud-access
  pointing to the cloud identifier of Cloud 1 will be created.  The
  permit-site leaf-list will be filled with a reference to Site 1 and
  Site 2.

     <?xml version="1.0"?>
     <l3vpn-svc xmlns="urn:ietf:params:xml:ns:yang:ietf-l3vpn-svc">
       <vpn-services>
         <vpn-service>
           <vpn-id>123456487</vpn-id>
           <cloud-accesses>
             <cloud-access>
               <cloud-identifier>Cloud1</cloud-identifier>
               <permit-site>site1</permit-site>
               <permit-site>site2</permit-site>
             </cloud-access>
           </cloud-accesses>
         </vpn-service>
       </vpn-services>
     </l3vpn-svc>

  If all sites except Site 1 require access to Cloud 2, a new cloud-
  access pointing to the cloud identifier of Cloud 2 will be created.
  The deny-site leaf-list will be filled with a reference to Site 1.

     <?xml version="1.0"?>
     <l3vpn-svc xmlns="urn:ietf:params:xml:ns:yang:ietf-l3vpn-svc">
       <vpn-services>
         <vpn-service>
           <vpn-id>123456487</vpn-id>
           <cloud-accesses>
             <cloud-access>
               <cloud-identifier>Cloud2</cloud-identifier>
               <deny-site>site1</deny-site>
             </cloud-access>
           </cloud-accesses>
         </vpn-service>
       </vpn-services>
     </l3vpn-svc>

  A service with more than one cloud access is functionally identical
  to multiple services each with a single cloud access, where the sites
  that belong to each service in the latter case correspond with the
  authorized sites for each cloud access in the former case.  However,
  defining a single service with multiple cloud accesses may be
  operationally simpler.





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6.2.3.  Multicast Service

  Multicast in IP VPNs is described in [RFC6513].

  If multicast support is required for an IP VPN, some global multicast
  parameters are required as input for the service request.

  Users of this model will need to provide the flavors of trees that
  will be used by customers within the IP VPN (customer tree).  The
  proposed model supports bidirectional, shared, and source-based trees
  (and can be augmented).  Multiple flavors of trees can be supported
  simultaneously.

                                 Operator network
                                 ______________
                                /               \
                               |                 |
                        (SSM tree)               |
  Recv (IGMPv3) -- Site2 ------- PE2             |
                               |             PE1 --- Site1 --- Source1
                               |                 |        \
                               |                 |         -- Source2
                               |                 |
                         (ASM tree)              |
  Recv (IGMPv2) -- Site3 ------- PE3             |
                               |                 |
                         (SSM tree)              |
  Recv (IGMPv3) -- Site4 ------- PE4             |
                               | /               |
  Recv (IGMPv2) -- Site5 --------                |
                         (ASM tree)              |
                               |                 |
                                \_______________/

  When an ASM flavor is requested, this model requires that the "rp"
  and "rp-discovery" parameters be filled.  Multiple RP-to-group
  mappings can be created using the "rp-group-mappings" container.  For
  each mapping, the SP can manage the RP service by setting the
  "provider-managed/enabled" leaf to true.  In the case of a provider-
  managed RP, the user can request RP redundancy and/or optimal traffic
  delivery.  Those parameters will help the SP select the appropriate
  technology or architecture to fulfill the customer service
  requirement: for instance, in the case of a request for optimal
  traffic delivery, an SP may use Anycast-RP or RP-tree-to-SPT
  switchover architectures.






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  In the case of a customer-managed RP, the RP address must be filled
  in the RP-to-group mappings using the "rp-address" leaf.  This leaf
  is not needed for a provider-managed RP.

  Users can define a specific mechanism for RP discovery, such as the
  "auto-rp", "static-rp", or "bsr-rp" modes.  By default, the model
  uses "static-rp" if ASM is requested.  A single rp-discovery
  mechanism is allowed for the VPN.  The "rp-discovery" container can
  be used for both provider-managed and customer-managed RPs.  In the
  case of a provider-managed RP, if the user wants to use "bsr-rp" as a
  discovery protocol, an SP should consider the provider-managed
  "rp-group-mappings" for the "bsr-rp" configuration.  The SP will then
  configure its selected RPs to be "bsr-rp-candidates".  In the case of
  a customer-managed RP and a "bsr-rp" discovery mechanism, the
  "rp-address" provided will be the bsr-rp candidate.

6.2.4.  Extranet VPNs

  There are some cases where a particular VPN needs access to resources
  (servers, hosts, etc.) that are external.  Those resources may be
  located in another VPN.

                 +-----------+           +-----------+
                /             \         /             \
     Site A -- |    VPN A      |  ---  |    VPN B      | --- Site B
                \             /         \             / (Shared
                 +-----------+           +-----------+   resources)


  In the figure above, VPN B has some resources on Site B that need to
  be available to some customers/partners.  VPN A must be able to
  access those VPN B resources.

  Such a VPN connection scenario can be achieved via a VPN policy as
  defined in Section 6.5.2.2.  But there are some simple cases where a
  particular VPN (VPN A) needs access to all resources in another VPN
  (VPN B).  The model provides an easy way to set up this connection
  using the "extranet-vpns" container.

  The extranet-vpns container defines a list of VPNs a particular VPN
  wants to access.  The extranet-vpns container must be used on
  customer VPNs accessing extranet resources in another VPN.  In the
  figure above, in order to provide VPN A with access to VPN B, the
  extranet-vpns container needs to be configured under VPN A with an
  entry corresponding to VPN B.  There is no service configuration
  requirement on VPN B.





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  Readers should note that even if there is no configuration
  requirement on VPN B, if VPN A lists VPN B as an extranet, all sites
  in VPN B will gain access to all sites in VPN A.

  The "site-role" leaf defines the role of the local VPN sites in the
  target extranet VPN service topology.  Site roles are defined in
  Section 6.4.  Based on this, the requirements described in
  Section 6.4 regarding the site-role leaf are also applicable here.

  In the example below, VPN A accesses VPN B resources through an
  extranet connection.  A Spoke role is required for VPN A sites, as
  sites from VPN A must not be able to communicate with each other
  through the extranet VPN connection.

     <?xml version="1.0"?>
     <l3vpn-svc xmlns="urn:ietf:params:xml:ns:yang:ietf-l3vpn-svc">
       <vpn-services>
         <vpn-service>
           <vpn-id>VPNB</vpn-id>
           <vpn-service-topology>hub-spoke</vpn-service-topology>
         </vpn-service>
         <vpn-service>
           <vpn-id>VPNA</vpn-id>
           <vpn-service-topology>any-to-any</vpn-service-topology>
           <extranet-vpns>
             <extranet-vpn>
               <vpn-id>VPNB</vpn-id>
               <local-sites-role>spoke-role</local-sites-role>
             </extranet-vpn>
           </extranet-vpns>
         </vpn-service>
       </vpn-services>
     </l3vpn-svc>

  This model does not define how the extranet configuration will be
  achieved.

  Any VPN interconnection scenario that is more complex (e.g., only
  certain parts of sites on VPN A accessing only certain parts of sites
  on VPN B) needs to be achieved using a VPN attachment as defined in
  Section 6.5.2, and especially a VPN policy as defined in
  Section 6.5.2.2.









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6.3.  Site Overview

  A site represents a connection of a customer office to one or more
  VPN services.  Each site is associated with one or more locations.

                                                   +-------------+
                                                  /               \
    +------------------+                   +-----|      VPN1       |
    |                  |                   |      \               /
    |  New York Office |------ (site) -----+       +-------------+
    |                  |                   |       +-------------+
    +------------------+                   |      /               \
                                           +-----|      VPN2       |
                                                  \               /
                                                   +-------------+

  A site has several characteristics:

  o  Unique identifier (site-id): uniquely identifies the site within
     the overall network infrastructure.  The identifier is a string
     that allows any encoding for the local administration of the VPN
     service.

  o  Locations (locations): site location information that allows easy
     retrieval of information from the nearest available resources.  A
     site may be composed of multiple locations.  Alternatively, two or
     more sites can be associated with the same location, by
     referencing the same location ID.

  o  Devices (devices): allows the customer to request one or more
     customer premises equipment entities from the SP for a particular
     site.

  o  Management (management): defines the type of management for the
     site -- for example, co-managed, customer-managed, or provider-
     managed.  See Section 6.10.

  o  Site network accesses (site-network-accesses): defines the list of
     network accesses associated with the sites, and their properties
     -- especially bearer, connection, and service parameters.

  A site-network-access represents an IP logical connection of a site.
  A site may have multiple site-network-accesses.








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        +------------------+             Site
        |                  |-----------------------------------
        |                  |****** (site-network-access#1) ******
        |  New York Office |
        |                  |****** (site-network-access#2) ******
        |                  |-----------------------------------
        +------------------+

  Multiple site-network-accesses are used, for instance, in the case of
  multihoming.  Some other meshing cases may also include multiple
  site-network-accesses.

  The site configuration is viewed as a global entity; we assume that
  it is mostly the management system's role to split the parameters
  between the different elements within the network.  For example, in
  the case of the site-network-access configuration, the management
  system needs to split the overall parameters between the PE
  configuration and the CE configuration.

6.3.1.  Devices and Locations

  A site may be composed of multiple locations.  All the locations will
  need to be configured as part of the "locations" container and list.
  A typical example of a multi-location site is a headquarters office
  in a city composed of multiple buildings.  Those buildings may be
  located in different parts of the city and may be linked by intra-
  city fibers (customer metropolitan area network).  In such a case,
  when connecting to a VPN service, the customer may ask for
  multihoming based on its distributed locations.

          New York Site

        +------------------+             Site
        | +--------------+ |-----------------------------------
        | | Manhattan    | |****** (site-network-access#1) ******
        | +--------------+ |
        | +--------------+ |
        | | Brooklyn     | |****** (site-network-access#2) ******
        | +--------------+ |
        |                  |-----------------------------------
        +------------------+

  A customer may also request some premises equipment entities (CEs)
  from the SP via the "devices" container.  Requesting a CE implies a
  provider-managed or co-managed model.  A particular device must be
  ordered to a particular already-configured location.  This would help





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  the SP send the device to the appropriate postal address.  In a
  multi-location site, a customer may, for example, request a CE for
  each location on the site where multihoming must be implemented.  In
  the figure above, one device may be requested for the Manhattan
  location and one other for the Brooklyn location.

  By using devices and locations, the user can influence the
  multihoming scenario he wants to implement: single CE, dual CE, etc.

6.3.2.  Site Network Accesses

  As mentioned earlier, a site may be multihomed.  Each IP network
  access for a site is defined in the "site-network-accesses"
  container.  The site-network-access parameter defines how the site is
  connected on the network and is split into three main classes of
  parameters:

  o  bearer: defines requirements of the attachment (below Layer 3).

  o  connection: defines Layer 3 protocol parameters of the attachment.

  o  availability: defines the site's availability policy.  The
     availability parameters are defined in Section 6.7.

  The site-network-access has a specific type (site-network-access-
  type).  This document defines two types:

  o  point-to-point: describes a point-to-point connection between the
     SP and the customer.

  o  multipoint: describes a multipoint connection between the SP and
     the customer.

  The type of site-network-access may have an impact on the parameters
  offered to the customer, e.g., an SP may not offer encryption for
  multipoint accesses.  It is up to the provider to decide what
  parameter is supported for point-to-point and/or multipoint accesses;
  this topic is out of scope for this document.  Some containers
  proposed in the model may require extensions in order to work
  properly for multipoint accesses.

6.3.2.1.  Bearer

  The bearer container defines the requirements for the site attachment
  to the provider network that are below Layer 3.

  The bearer parameters will help determine the access media to be
  used.  This is further described in Section 6.6.3.



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6.3.2.2.  Connection

  The "ip-connection" container defines the protocol parameters of the
  attachment (IPv4 and IPv6).  Depending on the management mode, it
  refers to PE-CE addressing or CE-to-customer-LAN addressing.  In any
  case, it describes the responsibility boundary between the provider
  and the customer.  For a customer-managed site, it refers to the
  PE-CE connection.  For a provider-managed site, it refers to the
  CE-to-LAN connection.

6.3.2.2.1.  IP Addressing

  An IP subnet can be configured for either IPv4 or IPv6 Layer 3
  protocols.  For a dual-stack connection, two subnets will be
  provided, one for each address family.

  The "address-allocation-type" determines how the address allocation
  needs to be done.  The current model defines five ways to perform IP
  address allocation:

  o  provider-dhcp: The provider will provide DHCP service for customer
     equipment; this is applicable to either the "IPv4" container or
     the "IPv6" container.

  o  provider-dhcp-relay: The provider will provide DHCP relay service
     for customer equipment; this is applicable to both IPv4 and IPv6
     addressing.  The customer needs to populate the DHCP server list
     to be used.

  o  static-address: Addresses will be assigned manually; this is
     applicable to both IPv4 and IPv6 addressing.

  o  slaac: This parameter enables stateless address autoconfiguration
     [RFC4862].  This is applicable to IPv6 only.

  o  provider-dhcp-slaac: The provider will provide DHCP service for
     customer equipment, as well as stateless address
     autoconfiguration.  This is applicable to IPv6 only.

  In the dynamic addressing mechanism, the SP is expected to provide at
  least the IP address, prefix length, and default gateway information.
  In the case of multiple site-network-access points belonging to the
  same VPN, address space allocated for one site-network-access should
  not conflict with one allocated for other site-network-accesses.







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6.3.2.2.2.  OAM

  A customer may require a specific IP connectivity fault detection
  mechanism on the IP connection.  The model supports BFD as a fault
  detection mechanism.  This can be extended with other mechanisms via
  augmentation.  The provider can propose some profiles to the
  customer, depending on the service level the customer wants to
  achieve.  Profile names must be communicated to the customer.  This
  communication is out of scope for this document.  Some fixed values
  for the holdtime period may also be imposed by the customer if the
  provider allows the customer this function.

  The "oam" container can easily be augmented by other mechanisms; in
  particular, work done by the LIME Working Group
  (https://datatracker.ietf.org/wg/lime/charter/) may be reused in
  applicable scenarios.

6.3.2.3.  Inheritance of Parameters Defined at Site Level and Site
         Network Access Level

  Some parameters can be configured at both the site level and the
  site-network-access level, e.g., routing, services, security.
  Inheritance applies when parameters are defined at the site level.
  If a parameter is configured at both the site level and the access
  level, the access-level parameter MUST override the site-level
  parameter.  Those parameters will be described later in this
  document.

  In terms of provisioning impact, it will be up to the implementation
  to decide on the appropriate behavior when modifying existing
  configurations.  But the SP will need to communicate to the user
  about the impact of using inheritance.  For example, if we consider
  that a site has already provisioned three site-network-accesses, what
  will happen if a customer changes a service parameter at the site
  level?  An implementation of this model may update the service
  parameters of all already-provisioned site-network-accesses (with
  potential impact on live traffic), or it may take into account this
  new parameter only for the new sites.

6.4.  Site Role

  A VPN has a particular service topology, as described in
  Section 6.2.1.  As a consequence, each site belonging to a VPN is
  assigned with a particular role in this topology.  The site-role leaf
  defines the role of the site in a particular VPN topology.

  In the any-to-any VPN service topology, all sites MUST have the same
  role, which will be "any-to-any-role".



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  In the Hub-and-Spoke VPN service topology or the Hub and Spoke
  disjoint VPN service topology, sites MUST have a Hub role or a Spoke
  role.

6.5.  Site Belonging to Multiple VPNs

6.5.1.  Site VPN Flavor

  A site may be part of one or multiple VPNs.  The "site-vpn-flavor"
  defines the way the VPN multiplexing is done.  The current version of
  the model supports four flavors:

  o  site-vpn-flavor-single: The site belongs to only one VPN.

  o  site-vpn-flavor-multi: The site belongs to multiple VPNs, and all
     the logical accesses of the sites belong to the same set of VPNs.

  o  site-vpn-flavor-sub: The site belongs to multiple VPNs with
     multiple logical accesses.  Each logical access may map to
     different VPNs (one or many).

  o  site-vpn-flavor-nni: The site represents an option A NNI.

6.5.1.1.  Single VPN Attachment: site-vpn-flavor-single

  The figure below describes a single VPN attachment.  The site
  connects to only one VPN.

                                                        +--------+
     +------------------+             Site             /          \
     |                  |-----------------------------|            |
     |                  |***(site-network-access#1)***|    VPN1    |
     |  New York Office |                             |            |
     |                  |***(site-network-access#2)***|            |
     |                  |-----------------------------|            |
     +------------------+                              \          /
                                                        +--------+














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6.5.1.2.  MultiVPN Attachment: site-vpn-flavor-multi

  The figure below describes a site connected to multiple VPNs.

                                                          +---------+
                                                     +---/----+      \
  +------------------+             Site             /   |      \      |
  |                  |--------------------------------- |       |VPN B|
  |                  |***(site-network-access#1)******* |       |     |
  |  New York Office |                             |    |       |     |
  |                  |***(site-network-access#2)*******  \      |    /
  |                  |-----------------------------| VPN A+-----|---+
  +------------------+                              \          /
                                                     +--------+


  In the example above, the New York office is multihomed.  Both
  logical accesses are using the same VPN attachment rules, and both
  are connected to VPN A and VPN B.

  Reaching VPN A or VPN B from the New York office will be done via
  destination-based routing.  Having the same destination reachable
  from the two VPNs may cause routing troubles.  The customer
  administration's role in this case would be to ensure the appropriate
  mapping of its prefixes in each VPN.

6.5.1.3.  SubVPN Attachment: site-vpn-flavor-sub

  The figure below describes a subVPN attachment.  The site connects to
  multiple VPNs, but each logical access is attached to a particular
  set of VPNs.  A typical use case for a subVPN is a customer site used
  by multiple affiliates with private resources for each affiliate that
  cannot be shared (communication between the affiliates is prevented).
  It is similar to having separate sites, but in the case of a SubVPN,
  the customer can share some physical components at a single location,
  while maintaining strong communication isolation between the
  affiliates.  In this example, site-network-access#1 is attached to
  VPN B, while site-network-access#2 is attached to VPN A.













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RFC 8299       YANG Data Model for L3VPN Service Delivery   January 2018


   +------------------+         Site                      +--------+
   |                  |----------------------------------/          \
   |                  |****(site-network-access#1)******|    VPN B   |
   |  New York Office |                                  \          /
   |                  |                                   +--------+
   |                  |                                   +--------+
   |                  |                                  /          \
   |                  |****(site-network-access#2)******|    VPN A   |
   |                  |                                  \          /
   |                  |                                   +--------+
   |                  |-----------------------------------
   +------------------+

  A multiVPN can be implemented in addition to a subVPN; as a
  consequence, each site-network-access can access multiple VPNs.  In
  the example below, site-network-access#1 is mapped to VPN B and VPN
  C, while site-network-access#2 is mapped to VPN A and VPN D.

  +-----------------+         Site                    +------+
  |                 |--------------------------------/       +-----+
  |                 |****(site-network-access#1)****| VPN B /       \
  | New York Office |                                \     |  VPN C  |
  |                 |                                 +-----\       /
  |                 |                                        +-----+
  |                 |
  |                 |                                 +-------+
  |                 |                                /        +-----+
  |                 |****(site-network-access#2)****| VPN A  /       \
  |                 |                                \      | VPN D   |
  |                 |                                 +------\       /
  |                 |---------------------------------        +-----+
  +-----------------+

  Multihoming is also possible with subVPNs; in this case, site-
  network-accesses are grouped, and a particular group will have access
  to the same set of VPNs.  In the example below, site-network-access#1
  and site-network-access#2 are part of the same group (multihomed
  together) and are mapped to VPN B and VPN C; in addition, site-
  network-access#3 and site-network-access#4 are part of the same group
  (multihomed together) and are mapped to VPN A and VPN D.











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RFC 8299       YANG Data Model for L3VPN Service Delivery   January 2018


  +-----------------+         Site                     +------+
  |                 |---------------------------------/       +-----+
  |                 |****(site-network-access#1)*****| VPN B /       \
  | New York Office |****(site-network-access#2)***** \     |  VPN C  |
  |                 |                                  +-----\       /
  |                 |                                         +-----+
  |                 |
  |                 |                                  +------+
  |                 |                                 /       +-----+
  |                 |****(site-network-access#3)*****| VPN A /       \
  |                 |****(site-network-access#4)***** \     | VPN D   |
  |                 |                                  +-----\       /
  |                 |----------------------------------       +-----+
  +-----------------+

  In terms of service configuration, a subVPN can be achieved by
  requesting that the site-network-access use the same bearer (see
  Section 6.6.4 for more details).

6.5.1.4.  NNI: site-vpn-flavor-nni

  A Network-to-Network Interface (NNI) scenario may be modeled using
  the sites container (see Section 6.15.1).  Using the sites container
  to model an NNI is only one possible option for NNIs (see
  Section 6.15).  This option is called "option A" by reference to the
  option A NNI defined in [RFC4364].  It is helpful for the SP to
  indicate that the requested VPN connection is not a regular site but
  rather is an NNI, as specific default device configuration parameters
  may be applied in the case of NNIs (e.g., ACLs, routing policies).






















Wu, et al.                   Standards Track                   [Page 40]

RFC 8299       YANG Data Model for L3VPN Service Delivery   January 2018


          SP A                                             SP B
     -------------------                         -------------------
    /                   \                       /                   \
   |                     |                     |                     |
   |                 ++++++++ Inter-AS link ++++++++                 |
   |                 +      +_______________+      +                 |
   |                 +  (VRF1)---(VPN1)----(VRF1)  +                 |
   |                 + ASBR +               + ASBR +                 |
   |                 +  (VRF2)---(VPN2)----(VRF2)  +                 |
   |                 +      +_______________+      +                 |
   |                 ++++++++               ++++++++                 |
   |                     |                     |                     |
   |                     |                     |                     |
   |                     |                     |                     |
   |                 ++++++++ Inter-AS link ++++++++                 |
   |                 +      +_______________+      +                 |
   |                 +  (VRF1)---(VPN1)----(VRF1)  +                 |
   |                 + ASBR +               + ASBR +                 |
   |                 +  (VRF2)---(VPN2)----(VRF2)  +                 |
   |                 +      +_______________+      +                 |
   |                 ++++++++               ++++++++                 |
   |                     |                     |                     |
   |                     |                     |                     |
    \                   /                       \                   /
     -------------------                         -------------------

  The figure above describes an option A NNI scenario that can be
  modeled using the sites container.  In order to connect its customer
  VPNs (VPN1 and VPN2) in SP B, SP A may request the creation of some
  site-network-accesses to SP B.  The site-vpn-flavor-nni will be used
  to inform SP B that this is an NNI and not a regular customer site.
  The site-vpn-flavor-nni may be multihomed and multiVPN as well.

6.5.2.  Attaching a Site to a VPN

  Due to the multiple site-vpn flavors, the attachment of a site to an
  IP VPN is done at the site-network-access (logical access) level
  through the "vpn-attachment" container.  The vpn-attachment container
  is mandatory.  The model provides two ways to attach a site to a VPN:

  o  By referencing the target VPN directly.

  o  By referencing a VPN policy for attachments that are more complex.

  A choice is implemented to allow the user to choose the flavor that
  provides the best fit.





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6.5.2.1.  Referencing a VPN

  Referencing a vpn-id provides an easy way to attach a particular
  logical access to a VPN.  This is the best way in the case of a
  single VPN attachment or subVPN with a single VPN attachment per
  logical access.  When referencing a vpn-id, the site-role setting
  must be added to express the role of the site in the target VPN
  service topology.

<?xml version="1.0"?>
<l3vpn-svc xmlns="urn:ietf:params:xml:ns:yang:ietf-l3vpn-svc">
 <vpn-services>
  <vpn-service>
   <vpn-id>VPNA</vpn-id>
  </vpn-service>
  <vpn-service>
   <vpn-id>VPNB</vpn-id>
  </vpn-service>
 </vpn-services>
 <sites>
  <site>
   <site-id>SITE1</site-id>
   <locations>
    <location>
     <location-id>L1</location-id>
    </location>
   </locations>
   <management>
    <type>customer-managed</type>
   </management>
   <security>
    <encryption>
     <layer>layer3</layer>
    </encryption>
   </security>
   <site-network-accesses>
    <site-network-access>
     <site-network-access-id>LA1</site-network-access-id>
     <ip-connection>
      <ipv4>
       <address-allocation-type>provider-dhcp</address-allocation-type>
      </ipv4>
      <ipv6>
       <address-allocation-type>provider-dhcp</address-allocation-type>
      </ipv6>
     </ip-connection>
     <service>
      <svc-mtu>1514</svc-mtu>



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      <svc-input-bandwidth>10000000</svc-input-bandwidth>
      <svc-output-bandwidth>10000000</svc-output-bandwidth>
     </service>
     <security>
      <encryption>
       <layer>layer3</layer>
      </encryption>
     </security>
     <location-reference>L1</location-reference>
     <vpn-attachment>
      <vpn-id>VPNA</vpn-id>
      <site-role>spoke-role</site-role>
     </vpn-attachment>
    </site-network-access>
    <site-network-access>
     <site-network-access-id>LA2</site-network-access-id>
     <ip-connection>
      <ipv4>
       <address-allocation-type>provider-dhcp</address-allocation-type>
      </ipv4>
      <ipv6>
       <address-allocation-type>provider-dhcp</address-allocation-type>
      </ipv6>
     </ip-connection>
     <service>
      <svc-mtu>1514</svc-mtu>
      <svc-input-bandwidth>10000000</svc-input-bandwidth>
      <svc-output-bandwidth>10000000</svc-output-bandwidth>
     </service>
     <security>
      <encryption>
       <layer>layer3</layer>
      </encryption>
     </security>
     <location-reference>L1</location-reference>
     <vpn-attachment>
      <vpn-id>VPNB</vpn-id>
      <site-role>spoke-role</site-role>
     </vpn-attachment>
    </site-network-access>
   </site-network-accesses>
  </site>
 </sites>
</l3vpn-svc>

  The example of a corresponding XML snippet above describes a subVPN
  case where a site (SITE1) has two logical accesses (LA1 and LA2),
  with LA1 attached to VPNA and LA2 attached to VPNB.



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RFC 8299       YANG Data Model for L3VPN Service Delivery   January 2018


6.5.2.2.  VPN Policy

  The "vpn-policy" list helps express a multiVPN scenario where a
  logical access belongs to multiple VPNs.  Multiple VPN policies can
  be created to handle the subVPN case where each logical access is
  part of a different set of VPNs.

  As a site can belong to multiple VPNs, the vpn-policy list may be
  composed of multiple entries.  A filter can be applied to specify
  that only some LANs of the site should be part of a particular VPN.
  Each time a site (or LAN) is attached to a VPN, the user must
  precisely describe its role (site-role) within the target VPN service
  topology.

    +--------------------------------------------------------------+
    |       Site1 ------ PE7                                       |
    +-------------------------+                 (VPN2)             |
                              |                                    |
    +-------------------------+                                    |
    |       Site2 ------ PE3               PE4 ------ Site3        |
    +----------------------------------+                           |
                                       |                           |
    +------------------------------------------------------------+ |
    |       Site4 ------ PE5           |   PE6 ------ Site5      | |
    |                                                            | |
    |                      (VPN3)                                | |
    +------------------------------------------------------------+ |
                                       |                           |
                                       +---------------------------+

  In the example above, Site5 is part of two VPNs: VPN3 and VPN2.  It
  will play a Hub role in VPN2 and an any-to-any role in VPN3.  We can
  express such a multiVPN scenario with the following XML snippet:

<?xml version="1.0"?>
<l3vpn-svc xmlns="urn:ietf:params:xml:ns:yang:ietf-l3vpn-svc">
 <vpn-services>
  <vpn-service>
   <vpn-id>VPN2</vpn-id>
  </vpn-service>
  <vpn-service>
   <vpn-id>VPN3</vpn-id>
  </vpn-service>
 </vpn-services>
 <sites>
  <site>
   <site-id>Site5</site-id>
   <devices>



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RFC 8299       YANG Data Model for L3VPN Service Delivery   January 2018


    <device>
     <device-id>D1</device-id>
    </device>
   </devices>
   <management>
    <type>provider-managed</type>
   </management>
   <security>
    <encryption>
     <layer>layer3</layer>
    </encryption>
   </security>
   <vpn-policies>
    <vpn-policy>
     <vpn-policy-id>POLICY1</vpn-policy-id>
     <entries>
      <id>ENTRY1</id>
      <vpn>
       <vpn-id>VPN2</vpn-id>
       <site-role>hub-role</site-role>
      </vpn>
     </entries>
     <entries>
      <id>ENTRY2</id>
      <vpn>
       <vpn-id>VPN3</vpn-id>
       <site-role>any-to-any-role</site-role>
      </vpn>
     </entries>
    </vpn-policy>
   </vpn-policies>
   <site-network-accesses>
    <site-network-access>
     <site-network-access-id>LA1</site-network-access-id>
     <device-reference>D1</device-reference>
     <ip-connection>
      <ipv4>
       <address-allocation-type>provider-dhcp</address-allocation-type>
      </ipv4>
      <ipv6>
       <address-allocation-type>provider-dhcp</address-allocation-type>
      </ipv6>
     </ip-connection>
     <service>
      <svc-mtu>1514</svc-mtu>
      <svc-input-bandwidth>10000000</svc-input-bandwidth>
      <svc-output-bandwidth>10000000</svc-output-bandwidth>
     </service>



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RFC 8299       YANG Data Model for L3VPN Service Delivery   January 2018


     <security>
      <encryption>
       <layer>layer3</layer>
      </encryption>
     </security>
     <vpn-attachment>
      <vpn-policy-id>POLICY1</vpn-policy-id>
     </vpn-attachment>
    </site-network-access>
   </site-network-accesses>
  </site>
 </sites>
</l3vpn-svc>

  Now, if a more-granular VPN attachment is necessary, filtering can be
  used.  For example, if only LAN1 from Site5 must be attached to VPN2
  as a Hub and only LAN2 must be attached to VPN3, the following XML
  snippet can be used:

     <?xml version="1.0"?>
     <l3vpn-svc xmlns="urn:ietf:params:xml:ns:yang:ietf-l3vpn-svc">
       <vpn-services>
         <vpn-service>
           <vpn-id>VPN2</vpn-id>
         </vpn-service>
         <vpn-service>
           <vpn-id>VPN3</vpn-id>
         </vpn-service>
       </vpn-services>
       <sites>
         <site>
           <site-id>Site5</site-id>
           <vpn-policies>
             <vpn-policy>
               <vpn-policy-id>POLICY1</vpn-policy-id>
               <entries>
                 <id>ENTRY1</id>
                 <filters>
                   <filter>
                     <type>lan</type>
                     <lan-tag>LAN1</lan-tag>
                   </filter>
                 </filters>
                 <vpn>
                   <vpn-id>VPN2</vpn-id>
                   <site-role>hub-role</site-role>
                 </vpn>
               </entries>



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RFC 8299       YANG Data Model for L3VPN Service Delivery   January 2018


               <entries>
                 <id>ENTRY2</id>
                 <filters>
                   <filter>
                     <type>lan</type>
                     <lan-tag>LAN2</lan-tag>
                   </filter>
                 </filters>
                 <vpn>
                   <vpn-id>VPN3</vpn-id>
                   <site-role>any-to-any-role</site-role>
                 </vpn>
               </entries>
             </vpn-policy>
           </vpn-policies>
           <site-network-accesses>
             <site-network-access>
               <site-network-access-id>LA1</site-network-access-id>
               <vpn-attachment>
                 <vpn-policy-id>POLICY1</vpn-policy-id>
               </vpn-attachment>
             </site-network-access>
           </site-network-accesses>
         </site>
       </sites>
     </l3vpn-svc>

6.6.  Deciding Where to Connect the Site

  The management system will have to determine where to connect each
  site-network-access of a particular site to the provider network
  (e.g., PE, aggregation switch).

  The current model defines parameters and constraints that can
  influence the meshing of the site-network-access.

  The management system MUST honor all customer constraints, or if a
  constraint is too strict and cannot be fulfilled, the management
  system MUST NOT provision the site and MUST provide information to
  the user about which constraints could not be fulfilled.  How the
  information is provided is out of scope for this document.  Whether
  or not to relax the constraint would then be left up to the user.

  Parameters such as site location (see Section 6.6.2) and access type
  are just hints (see Section 6.6.3) for the management system for
  service placement.





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RFC 8299       YANG Data Model for L3VPN Service Delivery   January 2018


  In addition to parameters and constraints, the management system's
  decision MAY be based on any other internal constraints that are left
  up to the SP: least load, distance, etc.

6.6.1.  Constraint: Device

  In the case of provider management or co-management, one or more
  devices have been ordered by the customer to a particular already-
  configured location.  The customer may force a particular site-
  network-access to be connected on a particular device that he
  ordered.

          New York Site

        +------------------+             Site
        | +--------------+ |-----------------------------------
        | | Manhattan    | |
        | |           CE1********* (site-network-access#1) ******
        | +--------------+ |
        | +--------------+ |
        | | Brooklyn  CE2********* (site-network-access#2) ******
        | +--------------+ |
        |                  |-----------------------------------
        +------------------+

  In the figure above, site-network-access#1 is associated with CE1 in
  the service request.  The SP must ensure the provisioning of this
  connection.

6.6.2.  Constraint/Parameter: Site Location

  The location information provided in this model MAY be used by a
  management system to determine the target PE to mesh the site (SP
  side).  A particular location must be associated with each site
  network access when configuring it.  The SP MUST honor the
  termination of the access on the location associated with the site
  network access (customer side).  The "country-code" in the site
  location SHOULD be expressed as an ISO ALPHA-2 code.

  The site-network-access location is determined by the "location-
  flavor".  In the case of a provider-managed or co-managed site, the
  user is expected to configure a "device-reference" (device case) that
  will bind the site-network-access to a particular device that the
  customer ordered.  As each device is already associated with a
  particular location, in such a case the location information is
  retrieved from the device location.  In the case of a customer-





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  managed site, the user is expected to configure a "location-
  reference" (location case); this provides a reference to an existing
  configured location and will help with placement.

                                       POP#1 (New York)
                                    +---------+
                                    |   PE1   |
               Site #1 ---...       |   PE2   |
              (Atlantic City)       |   PE3   |
                                    +---------+

                                       POP#2 (Washington)
                                    +---------+
                                    |   PE4   |
                                    |   PE5   |
                                    |   PE6   |
                                    +---------+

                                       POP#3 (Philadelphia)
                                    +---------+
                                    |   PE7   |
               Site #2 CE#1---...   |   PE8   |
              (Reston)              |   PE9   |
                                    +---------+


  In the example above, Site #1 is a customer-managed site with a
  location L1, while Site #2 is a provider-managed site for which a CE
  (CE#1) was ordered.  Site #2 is configured with L2 as its location.
  When configuring a site-network-access for Site #1, the user will
  need to reference location L1 so that the management system will know
  that the access will need to terminate on this location.  Then, for
  distance reasons, this management system may mesh Site #1 on a PE in
  the Philadelphia POP.  It may also take into account resources
  available on PEs to determine the exact target PE (e.g., least
  loaded).  For Site #2, the user is expected to configure the site-
  network-access with a device-reference to CE#1 so that the management
  system will know that the access must terminate on the location of
  CE#1 and must be connected to CE#1.  For placement of the SP side of
  the access connection, in the case of the nearest PE used, it may
  mesh Site #2 on the Washington POP.

6.6.3.  Constraint/Parameter: Access Type

  The management system needs to elect the access media to connect the
  site to the customer (for example, xDSL, leased line, Ethernet
  backhaul).  The customer may provide some parameters/constraints that
  will provide hints to the management system.



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  The bearer container information SHOULD be the first piece of
  information considered when making this decision:

  o  The "requested-type" parameter provides information about the
     media type that the customer would like to use.  If the "strict"
     leaf is equal to "true", this MUST be considered a strict
     constraint so that the management system cannot connect the site
     with another media type.  If the "strict" leaf is equal to "false"
     (default) and if the requested media type cannot be fulfilled, the
     management system can select another media type.  The supported
     media types SHOULD be communicated by the SP to the customer via a
     mechanism that is out of scope for this document.

  o  The "always-on" leaf defines a strict constraint: if set to true,
     the management system MUST elect a media type that is "always-on"
     (e.g., this means no dial access type).

  o  The "bearer-reference" parameter is used in cases where the
     customer has already ordered a network connection to the SP apart
     from the IP VPN site and wants to reuse this connection.  The
     string used is an internal reference from the SP and describes the
     already-available connection.  This is also a strict requirement
     that cannot be relaxed.  How the reference is given to the
     customer is out of scope for this document, but as a pure example,
     when the customer ordered the bearer (through a process that is
     out of scope for this model), the SP may have provided the bearer
     reference that can be used for provisioning services on top.

  Any other internal parameters from the SP can also be used.  The
  management system MAY use other parameters, such as the requested
  "svc-input-bandwidth" and "svc-output-bandwidth", to help decide
  which access type to use.

6.6.4.  Constraint: Access Diversity

  Each site-network-access may have one or more constraints that would
  drive the placement of the access.  By default, the model assumes
  that there are no constraints, but allocation of a unique bearer per
  site-network-access is expected.

  In order to help with the different placement scenarios, a site-
  network-access may be tagged using one or multiple group identifiers.
  The group identifier is a string, so it can accommodate both explicit
  naming of a group of sites (e.g., "multihomed-set1" or "subVPN") and
  the use of a numbered identifier (e.g., 12345678).  The meaning of
  each group-id is local to each customer administrator, and the
  management system MUST ensure that different customers can use the
  same group-ids.  One or more group-ids can also be defined at the



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  site level; as a consequence, all site-network-accesses under the
  site MUST inherit the group-ids of the site they belong to.  When, in
  addition to the site group-ids some group-ids are defined at the
  site-network-access level, the management system MUST consider the
  union of all groups (site level and site network access level) for
  this particular site-network-access.

  For an already-configured site-network-access, each constraint MUST
  be expressed against a targeted set of site-network-accesses.  This
  site-network-access MUST never be taken into account in the targeted
  set -- for example, "My site-network-access S must not be connected
  on the same POP as the site-network-accesses that are part of Group
  10."  The set of site-network-accesses against which the constraint
  is evaluated can be expressed as a list of groups, "all-other-
  accesses", or "all-other-groups".  The all-other-accesses option
  means that the current site-network-access constraint MUST be
  evaluated against all the other site-network-accesses belonging to
  the current site.  The all-other-groups option means that the
  constraint MUST be evaluated against all groups that the current
  site-network-access does not belong to.

  The current model defines multiple constraint-types:

  o  pe-diverse: The current site-network-access MUST NOT be connected
     to the same PE as the targeted site-network-accesses.

  o  pop-diverse: The current site-network-access MUST NOT be connected
     to the same POP as the targeted site-network-accesses.

  o  linecard-diverse: The current site-network-access MUST NOT be
     connected to the same linecard as the targeted site-network-
     accesses.

  o  bearer-diverse: The current site-network-access MUST NOT use
     common bearer components compared to bearers used by the targeted
     site-network-accesses.  "bearer-diverse" provides some level of
     diversity at the access level.  As an example, two bearer-diverse
     site-network-accesses must not use the same DSLAM, BAS, or Layer 2
     switch.

  o  same-pe: The current site-network-access MUST be connected to the
     same PE as the targeted site-network-accesses.

  o  same-bearer: The current site-network-access MUST be connected
     using the same bearer as the targeted site-network-accesses.

  These constraint-types can be extended through augmentation.




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  Each constraint is expressed as "The site-network-access S must be
  <constraint-type> (e.g., pe-diverse, pop-diverse) from these <target>
  site-network-accesses."

  The group-id used to target some site-network-accesses may be the
  same as the one used by the current site-network-access.  This eases
  the configuration of scenarios where a group of site-network-access
  points has a constraint between the access points in the group.  As
  an example, if we want a set of sites (Site#1 to Site#5) to be
  connected on different PEs, we can tag them with the same group-id
  and express a pe-diverse constraint for this group-id with the
  following XML snippet:

<?xml version="1.0"?>
<l3vpn-svc xmlns="urn:ietf:params:xml:ns:yang:ietf-l3vpn-svc">
 <vpn-services>
  <vpn-service>
   <vpn-id>VPNA</vpn-id>
  </vpn-service>
 </vpn-services>
 <sites>
  <site>
   <site-id>SITE1</site-id>
   <locations>
    <location>
     <location-id>L1</location-id>
    </location>
   </locations>
   <management>
    <type>customer-managed</type>
   </management>
   <site-network-accesses>
    <site-network-access>
     <site-network-access-id>1</site-network-access-id>
     <ip-connection>
      <ipv4>
       <address-allocation-type>provider-dhcp</address-allocation-type>
      </ipv4>
      <ipv6>
       <address-allocation-type>provider-dhcp</address-allocation-type>
      </ipv6>
     </ip-connection>
     <service>
      <svc-mtu>1514</svc-mtu>
      <svc-input-bandwidth>10000000</svc-input-bandwidth>
      <svc-output-bandwidth>10000000</svc-output-bandwidth>
     </service>
     <security>



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      <encryption>
       <layer>layer3</layer>
      </encryption>
     </security>
     <location-reference>L1</location-reference>
     <access-diversity>
      <groups>
       <group>
        <group-id>10</group-id>
       </group>
      </groups>
      <constraints>
       <constraint>
        <constraint-type>pe-diverse</constraint-type>
        <target>
         <group>
          <group-id>10</group-id>
         </group>
        </target>
       </constraint>
      </constraints>
     </access-diversity>
     <vpn-attachment>
      <vpn-id>VPNA</vpn-id>
      <site-role>spoke-role</site-role>
     </vpn-attachment>
    </site-network-access>
   </site-network-accesses>
  </site>
  <site>
   <site-id>SITE2</site-id>
   <locations>
    <location>
     <location-id>L1</location-id>
    </location>
   </locations>
   <management>
    <type>customer-managed</type>
   </management>
   <security>
    <encryption>
     <layer>layer3</layer>
    </encryption>
   </security>
   <site-network-accesses>
    <site-network-access>
     <site-network-access-id>1</site-network-access-id>
     <ip-connection>



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      <ipv4>
       <address-allocation-type>provider-dhcp</address-allocation-type>
      </ipv4>
      <ipv6>
       <address-allocation-type>provider-dhcp</address-allocation-type>
      </ipv6>
     </ip-connection>
     <service>
      <svc-mtu>1514</svc-mtu>
      <svc-input-bandwidth>10000000</svc-input-bandwidth>
      <svc-output-bandwidth>10000000</svc-output-bandwidth>
     </service>
     <security>
      <encryption>
       <layer>layer3</layer>
      </encryption>
     </security>
     <location-reference>L1</location-reference>
     <access-diversity>
      <groups>
       <group>
        <group-id>10</group-id>
       </group>
      </groups>
      <constraints>
       <constraint>
        <constraint-type>pe-diverse</constraint-type>
        <target>
         <group>
          <group-id>10</group-id>
         </group>
        </target>
       </constraint>
      </constraints>
     </access-diversity>
     <vpn-attachment>
      <vpn-id>VPNA</vpn-id>
      <site-role>spoke-role</site-role>
     </vpn-attachment>
    </site-network-access>
   </site-network-accesses>
  </site>
      ...
  <site>
   <site-id>SITE5</site-id>
   <locations>
    <location>
     <location-id>L1</location-id>



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    </location>
   </locations>
   <management>
    <type>customer-managed</type>
   </management>
   <security>
    <encryption>
     <layer>layer3</layer>
    </encryption>
   </security>
   <site-network-accesses>
    <site-network-access>
     <site-network-access-id>1</site-network-access-id>
     <ip-connection>
      <ipv4>
       <address-allocation-type>provider-dhcp</address-allocation-type>
      </ipv4>
      <ipv6>
       <address-allocation-type>provider-dhcp</address-allocation-type>
      </ipv6>
     </ip-connection>
     <service>
      <svc-mtu>1514</svc-mtu>
      <svc-input-bandwidth>10000000</svc-input-bandwidth>
      <svc-output-bandwidth>10000000</svc-output-bandwidth>
     </service>
     <security>
      <encryption>
       <layer>layer3</layer>
      </encryption>
     </security>
     <location-reference>L1</location-reference>
     <access-diversity>
      <groups>
       <group>
        <group-id>10</group-id>
       </group>
      </groups>
      <constraints>
       <constraint>
        <constraint-type>pe-diverse</constraint-type>
        <target>
         <group>
          <group-id>10</group-id>
         </group>
        </target>
       </constraint>
      </constraints>



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     </access-diversity>
     <vpn-attachment>
      <vpn-id>VPNA</vpn-id>
      <site-role>spoke-role</site-role>
     </vpn-attachment>
    </site-network-access>
   </site-network-accesses>
  </site>
 </sites>
</l3vpn-svc>

  The group-id used to target some site-network-accesses may also be
  different than the one used by the current site-network-access.  This
  can be used to express that a group of sites has some constraints
  against another group of sites, but there is no constraint within the
  group.  For example, we consider a set of six sites and two groups;
  we want to ensure that a site in the first group must be pop-diverse
  from a site in the second group.  The example of a corresponding XML
  snippet is described as follows:

<?xml version="1.0"?>
<l3vpn-svc xmlns="urn:ietf:params:xml:ns:yang:ietf-l3vpn-svc">
 <vpn-services>
  <vpn-service>
   <vpn-id>VPNA</vpn-id>
  </vpn-service>
 </vpn-services>
 <sites>
  <site>
   <site-id>SITE1</site-id>
   <site-network-accesses>
    <site-network-access>
     <site-network-access-id>1</site-network-access-id>
     <access-diversity>
      <groups>
       <group>
        <group-id>10</group-id>
       </group>
      </groups>
      <constraints>
       <constraint>
        <constraint-type>pop-diverse</constraint-type>
        <target>
         <group>
          <group-id>20</group-id>
         </group>
        </target>
       </constraint>



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      </constraints>
     </access-diversity>
     <vpn-attachment>
      <vpn-id>VPNA</vpn-id>
      <site-role>spoke-role</site-role>
     </vpn-attachment>
    </site-network-access>
   </site-network-accesses>
  </site>
  <site>
   <site-id>SITE2</site-id>
   <site-network-accesses>
    <site-network-access>
     <site-network-access-id>1</site-network-access-id>
     <access-diversity>
      <groups>
       <group>
        <group-id>10</group-id>
       </group>
      </groups>
      <constraints>
       <constraint>
        <constraint-type>pop-diverse</constraint-type>
        <target>
         <group>
          <group-id>20</group-id>
         </group>
        </target>
       </constraint>
      </constraints>
     </access-diversity>
     <vpn-attachment>
      <vpn-id>VPNA</vpn-id>
      <site-role>spoke-role</site-role>
     </vpn-attachment>
    </site-network-access>
   </site-network-accesses>
  </site>
      ...
  <site>
   <site-id>SITE5</site-id>
   <site-network-accesses>
    <site-network-access>
     <site-network-access-id>1</site-network-access-id>
     <access-diversity>
      <groups>
       <group>
        <group-id>20</group-id>



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       </group>
      </groups>
      <constraints>
       <constraint>
        <constraint-type>pop-diverse</constraint-type>
        <target>
         <group>
          <group-id>10</group-id>
         </group>
        </target>
       </constraint>
      </constraints>
     </access-diversity>
     <vpn-attachment>
      <vpn-id>VPNA</vpn-id>
      <site-role>spoke-role</site-role>
     </vpn-attachment>
    </site-network-access>
   </site-network-accesses>
  </site>
  <site>
   <site-id>SITE6</site-id>
   <locations>
    <location>
     <location-id>L1</location-id>
    </location>
   </locations>
   <management>
    <type>customer-managed</type>
   </management>
   <security>
    <encryption>
     <layer>layer3</layer>
    </encryption>
   </security>
   <site-network-accesses>
    <site-network-access>
     <site-network-access-id>1</site-network-access-id>
     <ip-connection>
      <ipv4>
       <address-allocation-type>provider-dhcp</address-allocation-type>
      </ipv4>
      <ipv6>
       <address-allocation-type>provider-dhcp</address-allocation-type>
      </ipv6>
     </ip-connection>
     <service>
      <svc-mtu>1514</svc-mtu>



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      <svc-input-bandwidth>10000000</svc-input-bandwidth>
      <svc-output-bandwidth>10000000</svc-output-bandwidth>
     </service>
     <security>
      <encryption>
       <layer>layer3</layer>
      </encryption>
     </security>
     <location-reference>L1</location-reference>
     <access-diversity>
      <groups>
       <group>
        <group-id>20</group-id>
       </group>
      </groups>
      <constraints>
       <constraint>
        <constraint-type>pop-diverse</constraint-type>
        <target>
         <group>
          <group-id>10</group-id>
         </group>
        </target>
       </constraint>
      </constraints>
     </access-diversity>
     <vpn-attachment>
      <vpn-id>VPNA</vpn-id>
      <site-role>spoke-role</site-role>
     </vpn-attachment>
    </site-network-access>
   </site-network-accesses>
  </site>
 </sites>
</l3vpn-svc>

6.6.5.  Infeasible Access Placement

  Some infeasible access placement scenarios could be created via the
  proposed configuration framework.  Such infeasible access placement
  scenarios could result from constraints that are too restrictive,
  leading to infeasible access placement in the network or conflicting
  constraints that would also lead to infeasible access placement.  An
  example of conflicting rules would be to request that site-network-
  access#1 be pe-diverse from site-network-access#2 and to request at
  the same time that site-network-access#2 be on the same PE as site-





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  network-access#1.  When the management system cannot determine the
  placement of a site-network-access, it MUST return an error message
  indicating that placement was not possible.

6.6.6.  Examples of Access Placement

6.6.6.1.  Multihoming

  The customer wants to create a multihomed site.  The site will be
  composed of two site-network-accesses; for resiliency purposes, the
  customer wants the two site-network-accesses to be meshed on
  different POPs.

                                                    POP#1
            +-------+                            +---------+
            |       |                            |   PE1   |
            |       |---site-network-access#1----|   PE2   |
            |       |                            |   PE3   |
            |       |                            +---------+
            | Site#1|
            |       |                               POP#2
            |       |                            +---------+
            |       |                            |   PE4   |
            |       |---site-network-access#2----|   PE5   |
            |       |                            |   PE6   |
            |       |                            +---------+
            +-------+

  This scenario can be expressed with the following XML snippet:

<?xml version="1.0"?>
<l3vpn-svc xmlns="urn:ietf:params:xml:ns:yang:ietf-l3vpn-svc">
 <vpn-services>
  <vpn-service>
   <vpn-id>VPNA</vpn-id>
  </vpn-service>
 </vpn-services>
 <sites>
  <site>
   <site-id>SITE1</site-id>
   <locations>
    <location>
     <location-id>L1</location-id>
    </location>
   </locations>
   <management>
    <type>customer-managed</type>
   </management>



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   <security>
    <encryption>
     <layer>layer3</layer>
    </encryption>
   </security>
   <site-network-accesses>
    <site-network-access>
     <site-network-access-id>1</site-network-access-id>
     <ip-connection>
      <ipv4>
       <address-allocation-type>provider-dhcp</address-allocation-type>
      </ipv4>
      <ipv6>
       <address-allocation-type>provider-dhcp</address-allocation-type>
      </ipv6>
     </ip-connection>
     <service>
      <svc-mtu>1514</svc-mtu>
      <svc-input-bandwidth>10000000</svc-input-bandwidth>
      <svc-output-bandwidth>10000000</svc-output-bandwidth>
     </service>
     <security>
      <encryption>
       <layer>layer3</layer>
      </encryption>
     </security>
     <location-reference>L1</location-reference>
     <access-diversity>
      <groups>
       <group>
        <group-id>10</group-id>
       </group>
      </groups>
      <constraints>
       <constraint>
        <constraint-type>pop-diverse</constraint-type>
        <target>
         <group>
          <group-id>20</group-id>
         </group>
        </target>
       </constraint>
      </constraints>
     </access-diversity>
     <vpn-attachment>
      <vpn-id>VPNA</vpn-id>
      <site-role>spoke-role</site-role>
     </vpn-attachment>



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    </site-network-access>
    <site-network-access>
     <site-network-access-id>2</site-network-access-id>
     <ip-connection>
      <ipv4>
       <address-allocation-type>provider-dhcp</address-allocation-type>
      </ipv4>
      <ipv6>
       <address-allocation-type>provider-dhcp</address-allocation-type>
      </ipv6>
     </ip-connection>
     <service>
      <svc-mtu>1514</svc-mtu>
      <svc-input-bandwidth>10000000</svc-input-bandwidth>
      <svc-output-bandwidth>10000000</svc-output-bandwidth>
     </service>
     <security>
      <encryption>
       <layer>layer3</layer>
      </encryption>
     </security>
     <location-reference>L1</location-reference>
     <access-diversity>
      <groups>
       <group>
        <group-id>20</group-id>
       </group>
      </groups>
      <constraints>
       <constraint>
        <constraint-type>pop-diverse</constraint-type>
        <target>
         <group>
          <group-id>10</group-id>
         </group>
        </target>
       </constraint>
      </constraints>
     </access-diversity>
     <vpn-attachment>
      <vpn-id>VPNA</vpn-id>
      <site-role>spoke-role</site-role>
     </vpn-attachment>
    </site-network-access>
   </site-network-accesses>
  </site>
 </sites>
</l3vpn-svc>



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  But it can also be expressed with the following XML snippet:

     <?xml version="1.0"?>
     <l3vpn-svc xmlns="urn:ietf:params:xml:ns:yang:ietf-l3vpn-svc">
       <vpn-services>
         <vpn-service>
           <vpn-id>VPNA</vpn-id>
         </vpn-service>
       </vpn-services>
       <sites>
         <site>
           <site-id>SITE1</site-id>
           <site-network-accesses>
             <site-network-access>
               <site-network-access-id>1</site-network-access-id>
               <access-diversity>
                 <constraints>
                   <constraint>
                     <constraint-type>pop-diverse</constraint-type>
                     <target>
                       <all-other-accesses/>
                     </target>
                   </constraint>
                 </constraints>
               </access-diversity>
               <vpn-attachment>
                 <vpn-id>VPNA</vpn-id>
                 <site-role>spoke-role</site-role>
               </vpn-attachment>
             </site-network-access>
             <site-network-access>
               <site-network-access-id>2</site-network-access-id>
               <access-diversity>
                 <constraints>
                   <constraint>
                     <constraint-type>pop-diverse</constraint-type>
                     <target>
                       <all-other-accesses/>
                     </target>
                   </constraint>
                 </constraints>
               </access-diversity>
               <vpn-attachment>
                 <vpn-id>VPNA</vpn-id>
                 <site-role>spoke-role</site-role>
               </vpn-attachment>
             </site-network-access>
           </site-network-accesses>



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         </site>
       </sites>
     </l3vpn-svc>

6.6.6.2.  Site Offload

  The customer has six branch offices in a particular region, and he
  wants to prevent having all branch offices connected on the same PE.

  He wants to express that three branch offices cannot be connected on
  the same linecard.  Also, the other branch offices must be connected
  on a different POP.  Those other branch offices cannot also be
  connected on the same linecard.

                                             POP#1
                                          +---------+
                                          |   PE1   |
                    Office#1 ---...       |   PE2   |
                    Office#2 ---...       |   PE3   |
                    Office#3 ---...       |   PE4   |
                                          +---------+

                                             POP#2
                                          +---------+
                    Office#4 ---...       |   PE5   |
                    Office#5 ---...       |   PE6   |
                    Office#6 ---...       |   PE7   |
                                          +---------+

  This scenario can be expressed as follows:

  o  We need to create two groups of sites: Group#10, which is composed
     of Office#1, Office#2, and Office#3; and Group#20, which is
     composed of Office#4, Office#5, and Office#6.

  o  Sites within Group#10 must be pop-diverse from sites within
     Group#20, and vice versa.

  o  Sites within Group#10 must be linecard-diverse from other sites in
     Group#10 (same for Group#20).

<?xml version="1.0"?>
<l3vpn-svc xmlns="urn:ietf:params:xml:ns:yang:ietf-l3vpn-svc">
 <vpn-services>
  <vpn-service>
   <vpn-id>VPNA</vpn-id>
  </vpn-service>
 </vpn-services>



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 <sites>
  <site>
   <site-id>Office1</site-id>
   <locations>
    <location>
     <location-id>L1</location-id>
    </location>
   </locations>
   <management>
    <type>customer-managed</type>
   </management>
   <security>
    <encryption>
     <layer>layer3</layer>
    </encryption>
   </security>
   <site-network-accesses>
    <site-network-access>
     <site-network-access-id>1</site-network-access-id>
     <ip-connection>
      <ipv4>
       <address-allocation-type>provider-dhcp</address-allocation-type>
      </ipv4>
      <ipv6>
       <address-allocation-type>provider-dhcp</address-allocation-type>
      </ipv6>
     </ip-connection>
     <service>
      <svc-mtu>1514</svc-mtu>
      <svc-input-bandwidth>10000000</svc-input-bandwidth>
      <svc-output-bandwidth>10000000</svc-output-bandwidth>
     </service>
     <security>
      <encryption>
       <layer>layer3</layer>
      </encryption>
     </security>
     <location-reference>L1</location-reference>
     <access-diversity>
      <groups>
       <group>
        <group-id>10</group-id>
       </group>
      </groups>
      <constraints>
       <constraint>
        <constraint-type>pop-diverse</constraint-type>
        <target>



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         <group>
          <group-id>20</group-id>
         </group>
        </target>
       </constraint>
       <constraint>
        <constraint-type>linecard-diverse</constraint-type>
        <target>
         <group>
          <group-id>10</group-id>
         </group>
        </target>
       </constraint>
      </constraints>
     </access-diversity>
     <vpn-attachment>
      <vpn-id>VPNA</vpn-id>
      <site-role>spoke-role</site-role>
     </vpn-attachment>
    </site-network-access>
   </site-network-accesses>
  </site>
  <site>
   <site-id>Office2</site-id>
   <locations>
    <location>
     <location-id>L1</location-id>
    </location>
   </locations>
   <management>
    <type>customer-managed</type>
   </management>
   <security>
    <encryption>
     <layer>layer3</layer>
    </encryption>
   </security>
   <site-network-accesses>
    <site-network-access>
     <site-network-access-id>1</site-network-access-id>
     <ip-connection>
      <ipv4>
       <address-allocation-type>provider-dhcp</address-allocation-type>
      </ipv4>
      <ipv6>
       <address-allocation-type>provider-dhcp</address-allocation-type>
      </ipv6>
     </ip-connection>



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     <service>
      <svc-mtu>1514</svc-mtu>
      <svc-input-bandwidth>10000000</svc-input-bandwidth>
      <svc-output-bandwidth>10000000</svc-output-bandwidth>
     </service>
     <security>
      <encryption>
       <layer>layer3</layer>
      </encryption>
     </security>
     <location-reference>L1</location-reference>
     <access-diversity>
      <groups>
       <group>
        <group-id>10</group-id>
       </group>
      </groups>
      <constraints>
       <constraint>
        <constraint-type>pop-diverse</constraint-type>
        <target>
         <group>
          <group-id>20</group-id>
         </group>
        </target>
       </constraint>
       <constraint>
        <constraint-type>linecard-diverse</constraint-type>
        <target>
         <group>
          <group-id>10</group-id>
         </group>
        </target>
       </constraint>
      </constraints>
     </access-diversity>
     <vpn-attachment>
      <vpn-id>VPNA</vpn-id>
      <site-role>spoke-role</site-role>
     </vpn-attachment>
    </site-network-access>
   </site-network-accesses>
  </site>
  <site>
   <site-id>Office3</site-id>
   <locations>
    <location>
     <location-id>L1</location-id>



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    </location>
   </locations>
   <management>
    <type>customer-managed</type>
   </management>
   <security>
    <encryption>
     <layer>layer3</layer>
    </encryption>
   </security>
   <site-network-accesses>
    <site-network-access>
     <site-network-access-id>1</site-network-access-id>
     <ip-connection>
      <ipv4>
       <address-allocation-type>provider-dhcp</address-allocation-type>
      </ipv4>
      <ipv6>
       <address-allocation-type>provider-dhcp</address-allocation-type>
      </ipv6>
     </ip-connection>
     <service>
      <svc-mtu>1514</svc-mtu>
      <svc-input-bandwidth>10000000</svc-input-bandwidth>
      <svc-output-bandwidth>10000000</svc-output-bandwidth>
     </service>
     <security>
      <encryption>
       <layer>layer3</layer>
      </encryption>
     </security>
     <location-reference>L1</location-reference>
     <access-diversity>
      <groups>
       <group>
        <group-id>10</group-id>
       </group>
      </groups>
      <constraints>
       <constraint>
        <constraint-type>pop-diverse</constraint-type>
        <target>
         <group>
          <group-id>20</group-id>
         </group>
        </target>
       </constraint>
       <constraint>



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        <constraint-type>linecard-diverse</constraint-type>
        <target>
         <group>
          <group-id>10</group-id>
         </group>
        </target>
       </constraint>
      </constraints>
     </access-diversity>
     <vpn-attachment>
      <vpn-id>VPNA</vpn-id>
      <site-role>spoke-role</site-role>
     </vpn-attachment>
    </site-network-access>
   </site-network-accesses>
  </site>
  <site>
   <site-id>Office4</site-id>
   <locations>
    <location>
     <location-id>L1</location-id>
    </location>
   </locations>
   <management>
    <type>customer-managed</type>
   </management>
   <security>
    <encryption>
     <layer>layer3</layer>
    </encryption>
   </security>
   <site-network-accesses>
    <site-network-access>
     <site-network-access-id>1</site-network-access-id>
     <ip-connection>
      <ipv4>
       <address-allocation-type>provider-dhcp</address-allocation-type>
      </ipv4>
      <ipv6>
       <address-allocation-type>provider-dhcp</address-allocation-type>
      </ipv6>
     </ip-connection>
     <service>
      <svc-mtu>1514</svc-mtu>
      <svc-input-bandwidth>10000000</svc-input-bandwidth>
      <svc-output-bandwidth>10000000</svc-output-bandwidth>
     </service>
     <security>



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      <encryption>
       <layer>layer3</layer>
      </encryption>
     </security>
     <location-reference>L1</location-reference>
     <access-diversity>
      <groups>
       <group>
        <group-id>20</group-id>
       </group>
      </groups>
      <constraints>
       <constraint>
        <constraint-type>pop-diverse</constraint-type>
        <target>
         <group>
          <group-id>10</group-id>
         </group>
        </target>
       </constraint>
       <constraint>
        <constraint-type>linecard-diverse</constraint-type>
        <target>
         <group>
          <group-id>20</group-id>
         </group>
        </target>
       </constraint>
      </constraints>
     </access-diversity>
     <vpn-attachment>
      <vpn-id>VPNA</vpn-id>
      <site-role>spoke-role</site-role>
     </vpn-attachment>
    </site-network-access>
   </site-network-accesses>
  </site>
  <site>
   <site-id>Office5</site-id>
   <locations>
    <location>
     <location-id>L1</location-id>
    </location>
   </locations>
   <management>
    <type>customer-managed</type>
   </management>
   <security>



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    <encryption>
     <layer>layer3</layer>
    </encryption>
   </security>
   <site-network-accesses>
    <site-network-access>
     <site-network-access-id>1</site-network-access-id>
     <ip-connection>
      <ipv4>
       <address-allocation-type>provider-dhcp</address-allocation-type>
      </ipv4>
      <ipv6>
       <address-allocation-type>provider-dhcp</address-allocation-type>
      </ipv6>
     </ip-connection>
     <service>
      <svc-mtu>1514</svc-mtu>
      <svc-input-bandwidth>10000000</svc-input-bandwidth>
      <svc-output-bandwidth>10000000</svc-output-bandwidth>
     </service>
     <security>
      <encryption>
       <layer>layer3</layer>
      </encryption>
     </security>
     <location-reference>L1</location-reference>
     <access-diversity>
      <groups>
       <group>
        <group-id>20</group-id>
       </group>
      </groups>
      <constraints>
       <constraint>
        <constraint-type>pop-diverse</constraint-type>
        <target>
         <group>
          <group-id>10</group-id>
         </group>
        </target>
       </constraint>
       <constraint>
        <constraint-type>linecard-diverse</constraint-type>
        <target>
         <group>
          <group-id>20</group-id>
         </group>
        </target>



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       </constraint>
      </constraints>
     </access-diversity>
     <vpn-attachment>
      <vpn-id>VPNA</vpn-id>
      <site-role>spoke-role</site-role>
     </vpn-attachment>
    </site-network-access>
   </site-network-accesses>
  </site>
  <site>
   <site-id>Office6</site-id>
   <locations>
    <location>
     <location-id>L1</location-id>
    </location>
   </locations>
   <management>
    <type>customer-managed</type>
   </management>
   <security>
    <encryption>
     <layer>layer3</layer>
    </encryption>
   </security>
   <site-network-accesses>
    <site-network-access>
     <site-network-access-id>1</site-network-access-id>
     <ip-connection>
      <ipv4>
       <address-allocation-type>provider-dhcp</address-allocation-type>
      </ipv4>
      <ipv6>
       <address-allocation-type>provider-dhcp</address-allocation-type>
      </ipv6>
     </ip-connection>
     <service>
      <svc-mtu>1514</svc-mtu>
      <svc-input-bandwidth>10000000</svc-input-bandwidth>
      <svc-output-bandwidth>10000000</svc-output-bandwidth>
     </service>
     <security>
      <encryption>
       <layer>layer3</layer>
      </encryption>
     </security>
     <location-reference>L1</location-reference>
     <access-diversity>



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      <groups>
       <group>
        <group-id>20</group-id>
       </group>
      </groups>
      <constraints>
       <constraint>
        <constraint-type>pop-diverse</constraint-type>
        <target>
         <group>
          <group-id>10</group-id>
         </group>
        </target>
       </constraint>
       <constraint>
        <constraint-type>linecard-diverse</constraint-type>
        <target>
         <group>
          <group-id>20</group-id>
         </group>
        </target>
       </constraint>
      </constraints>
     </access-diversity>
     <vpn-attachment>
      <vpn-id>VPNA</vpn-id>
      <site-role>spoke-role</site-role>
     </vpn-attachment>
    </site-network-access>
   </site-network-accesses>
  </site>
 </sites>
</l3vpn-svc>

6.6.6.3.  Parallel Links

  To increase its site bandwidth at lower cost, a customer wants to
  order two parallel site-network-accesses that will be connected to
  the same PE.

                   *******site-network-access#1**********
            Site 1 *******site-network-access#2********** PE1









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  This scenario can be expressed with the following XML snippet:

     <?xml version="1.0"?>
     <l3vpn-svc xmlns="urn:ietf:params:xml:ns:yang:ietf-l3vpn-svc">
       <vpn-services>
         <vpn-service>
           <vpn-id>VPNB</vpn-id>
         </vpn-service>
       </vpn-services>
       <sites>
         <site>
           <site-id>SITE1</site-id>
           <site-network-accesses>
             <site-network-access>
               <site-network-access-id>1</site-network-access-id>
               <access-diversity>
                 <groups>
                   <group>
                     <group-id>PE-linkgrp-1</group-id>
                   </group>
                 </groups>
                 <constraints>
                   <constraint>
                     <constraint-type>same-pe</constraint-type>
                     <target>
                       <group>
                         <group-id>PE-linkgrp-1</group-id>
                       </group>
                     </target>
                   </constraint>
                 </constraints>
               </access-diversity>
               <vpn-attachment>
                 <vpn-id>VPNB</vpn-id>
                 <site-role>spoke-role</site-role>
               </vpn-attachment>
             </site-network-access>
             <site-network-access>
               <site-network-access-id>2</site-network-access-id>
               <access-diversity>
                 <groups>
                   <group>
                     <group-id>PE-linkgrp-1</group-id>
                   </group>
                 </groups>
                 <constraints>
                   <constraint>
                     <constraint-type>same-pe</constraint-type>



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                     <target>
                       <group>
                         <group-id>PE-linkgrp-1</group-id>
                       </group>
                     </target>
                   </constraint>
                 </constraints>
               </access-diversity>
               <vpn-attachment>
                 <vpn-id>VPNB</vpn-id>
                 <site-role>spoke-role</site-role>
               </vpn-attachment>
             </site-network-access>
           </site-network-accesses>
         </site>
       </sites>
     </l3vpn-svc>

6.6.6.4.  SubVPN with Multihoming

  A customer has a site that is dual-homed.  The dual-homing must be
  done on two different PEs.  The customer also wants to implement two
  subVPNs on those multihomed accesses.

  +-----------------+         Site                     +------+
  |                 |---------------------------------/       +-----+
  |                 |****(site-network-access#1)*****| VPN B /       \
  | New York Office |****(site-network-access#2)************| VPN C   |
  |                 |                                  +-----\       /
  |                 |                                         +-----+
  |                 |
  |                 |                                  +------+
  |                 |                                 /       +-----+
  |                 |****(site-network-access#3)*****| VPN B /       \
  |                 |****(site-network-access#4)************| VPN C   |
  |                 |                                  +-----\       /
  |                 |-----------------------------------      +-----+
  +-----------------+

  This scenario can be expressed as follows:

  o  The site will have four site network accesses (two subVPNs coupled
     via dual-homing).

  o  Site-network-access#1 and site-network-access#3 will correspond to
     the multihoming of subVPN B.  A PE-diverse constraint is required
     between them.




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  o  Site-network-access#2 and site-network-access#4 will correspond to
     the multihoming of subVPN C.  A PE-diverse constraint is required
     between them.

  o  To ensure proper usage of the same bearer for the subVPN, site-
     network-access#1 and site-network-access#2 must share the same
     bearer as site-network-access#3 and site-network-access#4.

<?xml version="1.0"?>
<l3vpn-svc xmlns="urn:ietf:params:xml:ns:yang:ietf-l3vpn-svc">
 <vpn-services>
  <vpn-service>
   <vpn-id>VPNB</vpn-id>
  </vpn-service>
  <vpn-service>
   <vpn-id>VPNC</vpn-id>
  </vpn-service>
 </vpn-services>
 <sites>
  <site>
   <site-id>SITE1</site-id>
   <locations>
    <location>
     <location-id>L1</location-id>
    </location>
   </locations>
   <management>
    <type>customer-managed</type>
   </management>
   <security>
    <encryption>
     <layer>layer3</layer>
    </encryption>
   </security>
   <site-network-accesses>
    <site-network-access>
     <site-network-access-id>1</site-network-access-id>
     <ip-connection>
      <ipv4>
       <address-allocation-type>provider-dhcp</address-allocation-type>
      </ipv4>
      <ipv6>
       <address-allocation-type>provider-dhcp</address-allocation-type>
      </ipv6>
     </ip-connection>
     <service>
      <svc-mtu>1514</svc-mtu>
      <svc-input-bandwidth>10000000</svc-input-bandwidth>



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      <svc-output-bandwidth>10000000</svc-output-bandwidth>
     </service>
     <security>
      <encryption>
       <layer>layer3</layer>
      </encryption>
     </security>
     <location-reference>L1</location-reference>
     <access-diversity>
      <groups>
       <group>
        <group-id>dualhomed-1</group-id>
       </group>
      </groups>
      <constraints>
       <constraint>
        <constraint-type>pe-diverse</constraint-type>
        <target>
         <group>
          <group-id>dualhomed-2</group-id>
         </group>
        </target>
       </constraint>
       <constraint>
        <constraint-type>same-bearer</constraint-type>
        <target>
         <group>
          <group-id>dualhomed-1</group-id>
         </group>
        </target>
       </constraint>
      </constraints>
     </access-diversity>
     <vpn-attachment>
      <vpn-id>VPNB</vpn-id>
      <site-role>spoke-role</site-role>
     </vpn-attachment>
    </site-network-access>
    <site-network-access>
     <site-network-access-id>2</site-network-access-id>
     <access-diversity>
      <groups>
       <group>
        <group-id>dualhomed-1</group-id>
       </group>
      </groups>
      <constraints>
       <constraint>



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        <constraint-type>pe-diverse</constraint-type>
        <target>
         <group>
          <group-id>dualhomed-2</group-id>
         </group>
        </target>
       </constraint>
       <constraint>
        <constraint-type>same-bearer</constraint-type>
        <target>
         <group>
          <group-id>dualhomed-1</group-id>
         </group>
        </target>
       </constraint>
      </constraints>
     </access-diversity>
     <vpn-attachment>
      <vpn-id>VPNC</vpn-id>
      <site-role>spoke-role</site-role>
     </vpn-attachment>
    </site-network-access>
    <site-network-access>
     <site-network-access-id>3</site-network-access-id>
     <ip-connection>
      <ipv4>
       <address-allocation-type>provider-dhcp</address-allocation-type>
      </ipv4>
      <ipv6>
       <address-allocation-type>provider-dhcp</address-allocation-type>
      </ipv6>
     </ip-connection>
     <service>
      <svc-mtu>1514</svc-mtu>
      <svc-input-bandwidth>10000000</svc-input-bandwidth>
      <svc-output-bandwidth>10000000</svc-output-bandwidth>
     </service>
     <security>
      <encryption>
       <layer>layer3</layer>
      </encryption>
     </security>
     <location-reference>L1</location-reference>
     <access-diversity>
      <groups>
       <group>
        <group-id>dualhomed-2</group-id>
       </group>



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      </groups>
      <constraints>
       <constraint>
        <constraint-type>pe-diverse</constraint-type>
        <target>
         <group>
          <group-id>dualhomed-1</group-id>
         </group>
        </target>
       </constraint>
       <constraint>
        <constraint-type>same-bearer</constraint-type>
        <target>
         <group>
          <group-id>dualhomed-2</group-id>
         </group>
        </target>
       </constraint>
      </constraints>
     </access-diversity>
     <vpn-attachment>
      <vpn-id>VPNB</vpn-id>
      <site-role>spoke-role</site-role>
     </vpn-attachment>
    </site-network-access>
    <site-network-access>
     <site-network-access-id>4</site-network-access-id>
     <ip-connection>
      <ipv4>
       <address-allocation-type>provider-dhcp</address-allocation-type>
      </ipv4>
      <ipv6>
       <address-allocation-type>provider-dhcp</address-allocation-type>
      </ipv6>
     </ip-connection>
     <service>
      <svc-mtu>1514</svc-mtu>
      <svc-input-bandwidth>10000000</svc-input-bandwidth>
      <svc-output-bandwidth>10000000</svc-output-bandwidth>
     </service>
     <security>
      <encryption>
       <layer>layer3</layer>
      </encryption>
     </security>
     <location-reference>L1</location-reference>
     <access-diversity>
      <groups>



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       <group>
        <group-id>dualhomed-2</group-id>
       </group>
      </groups>
      <constraints>
       <constraint>
        <constraint-type>pe-diverse</constraint-type>
        <target>
         <group>
          <group-id>dualhomed-1</group-id>
         </group>
        </target>
       </constraint>
       <constraint>
        <constraint-type>same-bearer</constraint-type>
        <target>
         <group>
          <group-id>dualhomed-2</group-id>
         </group>
        </target>
       </constraint>
      </constraints>
     </access-diversity>
     <vpn-attachment>
      <vpn-id>VPNC</vpn-id>
      <site-role>spoke-role</site-role>
     </vpn-attachment>
    </site-network-access>
   </site-network-accesses>
  </site>
 </sites>
</l3vpn-svc>

6.6.7.  Route Distinguisher and VRF Allocation

  The route distinguisher (RD) is a critical parameter of PE-based
  L3VPNs as described in [RFC4364] that provides the ability to
  distinguish common addressing plans in different VPNs.  As for route
  targets (RTs), a management system is expected to allocate a VRF on
  the target PE and an RD for this VRF.

  If a VRF already exists on the target PE and the VRF fulfills the
  connectivity constraints for the site, there is no need to recreate
  another VRF, and the site MAY be meshed within this existing VRF.
  How the management system checks that an existing VRF fulfills the
  connectivity constraints for a site is out of scope for this
  document.




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  If no such VRF exists on the target PE, the management system has to
  initiate the creation of a new VRF on the target PE and has to
  allocate a new RD for this new VRF.

  The management system MAY apply a per-VPN or per-VRF allocation
  policy for the RD, depending on the SP's policy.  In a per-VPN
  allocation policy, all VRFs (dispatched on multiple PEs) within a VPN
  will share the same RD value.  In a per-VRF model, all VRFs should
  always have a unique RD value.  Some other allocation policies are
  also possible, and this document does not restrict the allocation
  policies to be used.

  The allocation of RDs MAY be done in the same way as RTs.  The
  examples provided in Section 6.2.1.1 could be reused in this
  scenario.

  Note that an SP MAY configure a target PE for an automated allocation
  of RDs.  In this case, there will be no need for any backend system
  to allocate an RD value.

6.7.  Site Network Access Availability

  A site may be multihomed, meaning that it has multiple site-network-
  access points.  Placement constraints defined in previous sections
  will help ensure physical diversity.

  When the site-network-accesses are placed on the network, a customer
  may want to use a particular routing policy on those accesses.

  The "site-network-access/availability" container defines parameters
  for site redundancy.  The "access-priority" leaf defines a preference
  for a particular access.  This preference is used to model load-
  balancing or primary/backup scenarios.  The higher the access-
  priority value, the higher the preference will be.

















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  The figure below describes how the access-priority attribute can be
  used.

      Hub#1 LAN (Primary/backup)          Hub#2 LAN (Load-sharing)
        |                                                     |
        |    access-priority 1          access-priority 1     |
        |--- CE1 ------- PE1            PE3 --------- CE3 --- |
        |                                                     |
        |                                                     |
        |--- CE2 ------- PE2            PE4 --------- CE4 --- |
        |    access-priority 2          access-priority 1     |

                                PE5
                                 |
                                 |
                                 |
                                CE5
                                 |
                            Spoke#1 site (Single-homed)

  In the figure above, Hub#2 requires load-sharing, so all the site-
  network-accesses must use the same access-priority value.  On the
  other hand, as Hub#1 requires a primary site-network-access and a
  backup site-network-access, a higher access-priority setting will be
  configured on the primary site-network-access.

  Scenarios that are more complex can be modeled.  Let's consider a Hub
  site with five accesses to the network (A1,A2,A3,A4,A5).  The
  customer wants to load-share its traffic on A1,A2 in the nominal
  situation.  If A1 and A2 fail, the customer wants to load-share its
  traffic on A3 and A4; finally, if A1 to A4 are down, he wants to use
  A5.  We can model this easily by configuring the following access-
  priority values: A1=100, A2=100, A3=50, A4=50, A5=10.

  The access-priority scenario has some limitations.  An access-
  priority scenario like the previous one with five accesses but with
  the constraint of having traffic load-shared between A3 and A4 in the
  case where A1 OR A2 is down is not achievable.  But the authors
  believe that using the access-priority attribute will cover most of
  the deployment use cases and that the model can still be extended via
  augmentation to support additional use cases.

6.8.  Traffic Protection

  The service model supports the ability to protect the traffic for a
  site.  Such protection provides a better level of availability in
  multihoming scenarios by, for example, using local-repair techniques




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  in case of failures.  The associated level of service guarantee would
  be based on an agreement between the customer and the SP and is out
  of scope for this document.

                Site#1                            Site#2
            CE1 ----- PE1 -- P1            P3 -- PE3 ---- CE3
             |                              |             |
             |                              |             |
            CE2 ----- PE2 -- P2            P4 -- PE4 ---- CE4
                      /
                     /
            CE5 ----+
               Site#3

  In the figure above, we consider an IP VPN service with three sites,
  including two dual-homed sites (Site#1 and Site#2).  For dual-homed
  sites, we consider PE1-CE1 and PE3-CE3 as primary and PE2-CE2,PE4-CE4
  as backup for the example (even if protection also applies to load-
  sharing scenarios).

  In order to protect Site#2 against a failure, a user may set the
  "traffic-protection/enabled" leaf to true for Site#2.  How the
  traffic protection will be implemented is out of scope for this
  document.  However, in such a case, we could consider traffic coming
  from a remote site (Site#1 or Site#3), where the primary path would
  use PE3 as the egress PE.  PE3 may have preprogrammed a backup
  forwarding entry pointing to the backup path (through PE4-CE4) for
  all prefixes going through the PE3-CE3 link.  How the backup path is
  computed is out of scope for this document.  When the PE3-CE3 link
  fails, traffic is still received by PE3, but PE3 automatically
  switches traffic to the backup entry; the path will therefore be
  PE1-P1-(...)-P3-PE3-PE4-CE4 until the remote PEs reconverge and use
  PE4 as the egress PE.

6.9.  Security

  The "security" container defines customer-specific security
  parameters for the site.  The security options supported in the model
  are limited but may be extended via augmentation.

6.9.1.  Authentication

  The current model does not support any authentication parameters for
  the site connection, but such parameters may be added in the
  "authentication" container through augmentation.






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6.9.2.  Encryption

  Traffic encryption can be requested on the connection.  It may be
  performed at Layer 2 or Layer 3 by selecting the appropriate
  enumeration in the "layer" leaf.  For example, an SP may use IPsec
  when a customer requests Layer 3 encryption.  The encryption profile
  can be SP defined or customer specific.

  When an SP profile is used and a key (e.g., a pre-shared key) is
  allocated by the provider to be used by a customer, the SP should
  provide a way to communicate the key in a secured way to the
  customer.

  When a customer profile is used, the model supports only a pre-shared
  key for authentication of the site connection, with the pre-shared
  key provided through the NETCONF or RESTCONF request.  A secure
  channel must be used to ensure that the pre-shared key cannot be
  intercepted.

  For security reasons, it may be necessary for the customer to change
  the pre-shared key on a regular basis.  To perform a key change, the
  user can ask the SP to change the pre-shared key by submitting a new
  pre-shared key for the site configuration (as shown below with a
  corresponding XML snippet).  This mechanism might not be hitless.



























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     <?xml version="1.0"?>
     <l3vpn-svc xmlns="urn:ietf:params:xml:ns:yang:ietf-l3vpn-svc">
       <vpn-services>
         <vpn-service>
           <vpn-id>VPNA</vpn-id>
         </vpn-service>
       </vpn-services>
       <sites>
         <site>
           <site-id>SITE1</site-id>
           <site-network-accesses>
             <site-network-access>
               <site-network-access-id>1</site-network-access-id>
               <security>
                 <encryption>
                   <encryption-profile>
                     <preshared-key>MY_NEW_KEY</preshared-key>
                   </encryption-profile>
                 </encryption>
               </security>
             </site-network-access>
           </site-network-accesses>
         </site>
       </sites>
     </l3vpn-svc>

  A hitless key change mechanism may be added through augmentation.

  Other key-management methodologies (e.g., PKI) may be added through
  augmentation.

6.10.  Management

  The model defines three types of common management options:

  o  provider-managed: The CE router is managed only by the provider.
     In this model, the responsibility boundary between the SP and the
     customer is between the CE and the customer network.

  o  customer-managed: The CE router is managed only by the customer.
     In this model, the responsibility boundary between the SP and the
     customer is between the PE and the CE.

  o  co-managed: The CE router is primarily managed by the provider; in
     addition, the SP allows customers to access the CE for
     configuration/monitoring purposes.  In the co-managed mode, the
     responsibility boundary is the same as the responsibility boundary
     for the provider-managed model.



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  Based on the management model, different security options MAY be
  derived.

  In the co-managed case, the model defines options for the management
  address family (IPv4 or IPv6) and the associated management address.

6.11.  Routing Protocols

  "routing-protocol" defines which routing protocol must be activated
  between the provider and the customer router.  The current model
  supports the following settings: bgp, rip, ospf, static, direct, and
  vrrp.

  The routing protocol defined applies at the provider-to-customer
  boundary.  Depending on how the management model is administered, it
  may apply to the PE-CE boundary or the CE-to-customer boundary.  In
  the case of a customer-managed site, the routing protocol defined
  will be activated between the PE and the CE router managed by the
  customer.  In the case of a provider-managed site, the routing
  protocol defined will be activated between the CE managed by the SP
  and the router or LAN belonging to the customer.  In this case, we
  expect the PE-CE routing to be configured based on the SP's rules, as
  both are managed by the same entity.

                                     Rtg protocol
             192.0.2.0/24 ----- CE ----------------- PE1

                          Customer-managed site

                   Rtg protocol
             Customer router ----- CE ----------------- PE1

                          Provider-managed site

  All the examples below will refer to a scenario for a customer-
  managed site.















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6.11.1.  Handling of Dual Stack

  All routing protocol types support dual stack by using the "address-
  family" leaf-list.

  Example of a corresponding XML snippet with dual stack using the same
  routing protocol:

     <?xml version="1.0"?>
     <l3vpn-svc xmlns="urn:ietf:params:xml:ns:yang:ietf-l3vpn-svc">
       <vpn-services>
         <vpn-service>
           <vpn-id>VPNA</vpn-id>
         </vpn-service>
       </vpn-services>
       <sites>
         <site>
           <site-id>SITE1</site-id>
           <routing-protocols>
             <routing-protocol>
               <type>static</type>
               <static>
                 <cascaded-lan-prefixes>
                   <ipv4-lan-prefixes>
                     <lan>192.0.2.0/24</lan>
                     <next-hop>203.0.113.1</next-hop>
                   </ipv4-lan-prefixes>
                   <ipv6-lan-prefixes>
                     <lan>2001:db8::1/64</lan>
                     <next-hop>2001:db8::2</next-hop>
                   </ipv6-lan-prefixes>
                 </cascaded-lan-prefixes>
               </static>
             </routing-protocol>
           </routing-protocols>
         </site>
       </sites>
     </l3vpn-svc>













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  Example of a corresponding XML snippet with dual stack using two
  different routing protocols:

     <?xml version="1.0"?>
     <l3vpn-svc xmlns="urn:ietf:params:xml:ns:yang:ietf-l3vpn-svc">
       <vpn-services>
         <vpn-service>
           <vpn-id>VPNA</vpn-id>
         </vpn-service>
       </vpn-services>
       <sites>
         <site>
           <site-id>SITE1</site-id>
           <routing-protocols>
             <routing-protocol>
               <type>rip</type>
               <rip>
                 <address-family>ipv4</address-family>
               </rip>
             </routing-protocol>
             <routing-protocol>
               <type>ospf</type>
               <ospf>
                 <address-family>ipv6</address-family>
                 <area-address>4.4.4.4</area-address>
               </ospf>
             </routing-protocol>
           </routing-protocols>
         </site>
       </sites>
     </l3vpn-svc>

6.11.2.  LAN Directly Connected to SP Network

  The routing protocol type "direct" SHOULD be used when a customer LAN
  is directly connected to the provider network and must be advertised
  in the IP VPN.

               LAN attached directly to provider network:

               192.0.2.0/24 ----- PE1

  In this case, the customer has a default route to the PE address.








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6.11.3.  LAN Directly Connected to SP Network with Redundancy

  The routing protocol type "vrrp" SHOULD be used and advertised in the
  IP VPN when

  o  the customer LAN is directly connected to the provider network,
     and

  o  LAN redundancy is expected.

  LAN attached directly to provider network with LAN redundancy:

                         192.0.2.0/24 ------ PE1
                                        |
                                        +--- PE2

  In this case, the customer has a default route to the SP network.

6.11.4.  Static Routing

  The routing protocol type "static" MAY be used when a customer LAN is
  connected to the provider network through a CE router and must be
  advertised in the IP VPN.  In this case, the static routes give next
  hops (nh) to the CE and to the PE.  The customer has a default route
  to the SP network.

                                Static rtg
       192.0.2.0/24 ------ CE -------------- PE
                            |                |
                            |      Static route 192.0.2.0/24 nh CE
            Static route 0.0.0.0/0 nh PE

6.11.5.  RIP Routing

  The routing protocol type "rip" MAY be used when a customer LAN is
  connected to the provider network through a CE router and must be
  advertised in the IP VPN.  For IPv4, the model assumes that RIP
  version 2 is used.

  In the case of dual-stack routing requested through this model, the
  management system will be responsible for configuring RIP (including
  the correct version number) and associated address families on
  network elements.

                                        RIP rtg
                192.0.2.0/24 ------ CE -------------- PE





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6.11.6.  OSPF Routing

  The routing protocol type "ospf" MAY be used when a customer LAN is
  connected to the provider network through a CE router and must be
  advertised in the IP VPN.

  It can be used to extend an existing OSPF network and interconnect
  different areas.  See [RFC4577] for more details.

                            +---------------------+
                            |                     |
                    OSPF    |                     | OSPF
                    area 1  |                     | area 2
   (OSPF                    |                     |          (OSPF
   area 1) --- CE ---------- PE               PE ----- CE --- area 2)
                            |                     |
                            +---------------------+

  The model also defines an option to create an OSPF sham link between
  two sites sharing the same area and having a backdoor link.  The sham
  link is created by referencing the target site sharing the same OSPF
  area.  The management system will be responsible for checking to see
  if there is already a sham link configured for this VPN and area
  between the same pair of PEs.  If there is no existing sham link, the
  management system will provision one.  This sham link MAY be reused
  by other sites.

                   +------------------------+
                   |                        |
                   |                        |
                   |  PE (--sham link--)PE  |
                   |    |                |  |
                   +----|----------------|--+
                        | OSPF area 1    | OSPF area 1
                        |                |
                        CE1             CE2
                        |                |
                  (OSPF area 1)     (OSPF area 1)
                        |                |
                        +----------------+

  Regarding dual-stack support, the user MAY specify both IPv4 and IPv6
  address families, if both protocols should be routed through OSPF.
  As OSPF uses separate protocol instances for IPv4 and IPv6, the
  management system will need to configure both OSPF version 2 and OSPF
  version 3 on the PE-CE link.





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  Other OSPF parameters, such as timers, are typically set by the SP
  and communicated to the customer outside the scope of this model.

  Example of a corresponding XML snippet with OSPF routing parameters
  in the service model:

     <?xml version="1.0"?>
     <l3vpn-svc xmlns="urn:ietf:params:xml:ns:yang:ietf-l3vpn-svc">
       <vpn-services>
         <vpn-service>
           <vpn-id>VPNA</vpn-id>
         </vpn-service>
       </vpn-services>
       <sites>
         <site>
           <site-id>SITE1</site-id>
           <routing-protocols>
             <routing-protocol>
               <type>ospf</type>
               <ospf>
                 <area-address>0.0.0.1</area-address>
                 <address-family>ipv4</address-family>
                 <address-family>ipv6</address-family>
               </ospf>
             </routing-protocol>
           </routing-protocols>
         </site>
       </sites>
     </l3vpn-svc>

  Example of PE configuration done by the management system:

                         router ospf 10
                          area 0.0.0.1
                           interface Ethernet0/0
                         !
                         router ospfv3 10
                          area 0.0.0.1
                           interface Ethernet0/0
                          !











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6.11.7.  BGP Routing

  The routing protocol type "bgp" MAY be used when a customer LAN is
  connected to the provider network through a CE router and must be
  advertised in the IP VPN.

                                          BGP rtg
                192.0.2.0/24 ------ CE -------------- PE

  The session addressing will be derived from connection parameters as
  well as the SP's knowledge of the addressing plan that is in use.

  In the case of dual-stack access, the user MAY request BGP routing
  for both IPv4 and IPv6 by specifying both address families.  It will
  be up to the SP and management system to determine how to describe
  the configuration (two BGP sessions, single, multi-session, etc.).
  This, along with other BGP parameters such as timers, is communicated
  to the customer outside the scope of this model.

  The service configuration below activates BGP on the PE-CE link for
  both IPv4 and IPv6.

  BGP activation requires the SP to know the address of the customer
  peer.  If the site-network-access connection addresses are used for
  BGP peering, the "static-address" allocation type for the IP
  connection MUST be used.  Other peering mechanisms are outside the
  scope of this model.  An example of a corresponding XML snippet is
  described as follows:

     <?xml version="1.0"?>
     <l3vpn-svc xmlns="urn:ietf:params:xml:ns:yang:ietf-l3vpn-svc">
       <vpn-services>
         <vpn-service>
           <vpn-id>VPNA</vpn-id>
         </vpn-service>
       </vpn-services>
       <sites>
         <site>
           <site-id>SITE1</site-id>
           <routing-protocols>
             <routing-protocol>
               <type>bgp</type>
               <bgp>
                 <autonomous-system>65000</autonomous-system>
                 <address-family>ipv4</address-family>
                 <address-family>ipv6</address-family>
               </bgp>
             </routing-protocol>



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           </routing-protocols>
         </site>
       </sites>
     </l3vpn-svc>

  Depending on the SP flavor, a management system can divide this
  service configuration into different flavors, as shown by the
  following examples.

  Example of PE configuration done by the management system (single
  IPv4 transport session):

           router bgp 100
            neighbor 203.0.113.2 remote-as 65000
            address-family ipv4 vrf Cust1
               neighbor 203.0.113.2 activate
            address-family ipv6 vrf Cust1
               neighbor 203.0.113.2 activate
               neighbor 203.0.113.2 route-map SET-NH-IPV6 out

  Example of PE configuration done by the management system (two
  sessions):

                  router bgp 100
                   neighbor 203.0.113.2 remote-as 65000
                   neighbor 2001::2 remote-as 65000
                   address-family ipv4 vrf Cust1
                      neighbor 203.0.113.2 activate
                   address-family ipv6 vrf Cust1
                      neighbor 2001::2 activate

  Example of PE configuration done by the management system (multi-
  session):

           router bgp 100
            neighbor 203.0.113.2 remote-as 65000
            neighbor 203.0.113.2 multisession per-af
            address-family ipv4 vrf Cust1
               neighbor 203.0.113.2 activate
            address-family ipv6 vrf Cust1
               neighbor 203.0.113.2 activate
               neighbor 203.0.113.2 route-map SET-NH-IPV6 out

6.12.  Service

  The service defines service parameters associated with the site.





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6.12.1.  Bandwidth

  The service bandwidth refers to the bandwidth requirement between the
  PE and the CE (WAN link bandwidth).  The requested bandwidth is
  expressed as svc-input-bandwidth and svc-output-bandwidth in bits per
  second.  The input/output direction uses the customer site as a
  reference: "input bandwidth" means download bandwidth for the site,
  and "output bandwidth" means upload bandwidth for the site.

  The service bandwidth is only configurable at the site-network-access
  level.

  Using a different input and output bandwidth will allow the SP to
  determine if the customer allows for asymmetric bandwidth access,
  such as ADSL.  It can also be used to set rate-limiting in a
  different way for uploading and downloading on a symmetric bandwidth
  access.

  The bandwidth is a service bandwidth expressed primarily as IP
  bandwidth, but if the customer enables MPLS for Carriers' Carriers
  (CsC), this becomes MPLS bandwidth.

6.12.2.  MTU

  The service MTU refers to the maximum PDU size that the customer may
  use.  If the customer sends packets that are longer than the
  requested service MTU, the network may discard it (or for IPv4,
  fragment it).

6.12.3.  QoS

  The model defines QoS parameters in an abstracted way:

  o  qos-classification-policy: policy that defines a set of ordered
     rules to classify customer traffic.

  o  qos-profile: QoS scheduling profile to be applied.

6.12.3.1.  QoS Classification

  QoS classification rules are handled by the "qos-classification-
  policy" container.  The qos-classification-policy container is an
  ordered list of rules that match a flow or application and set the
  appropriate target class of service (target-class-id).  The user can
  define the match using an application reference or a flow definition
  that is more specific (e.g., based on Layer 3 source and destination
  addresses, Layer 4 ports, and Layer 4 protocol).  When a flow
  definition is used, the user can employ a "target-sites" leaf-list to



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  identify the destination of a flow rather than using destination IP
  addresses.  In such a case, an association between the site
  abstraction and the IP addresses used by this site must be done
  dynamically.  How this association is done is out of scope for this
  document.  The association of a site to an IP VPN is done through the
  "vpn-attachment" container.  Therefore, the user can also employ
  "target-sites" leaf-list and "vpn-attachment" to identify the
  destination of a flow targeted to a specific VPN service.  A rule
  that does not have a match statement is considered a match-all rule.
  An SP may implement a default terminal classification rule if the
  customer does not provide it.  It will be up to the SP to determine
  its default target class.  The current model defines some
  applications, but new application identities may be added through
  augmentation.  The exact meaning of each application identity is up
  to the SP, so it will be necessary for the SP to advise the customer
  on the usage of application matching.

  Where the classification is done depends on the SP's implementation
  of the service, but classification concerns the flow coming from the
  customer site and entering the network.

                                          Provider network
                                     +-----------------------+
              192.0.2.0/24
           198.51.100.0/24 ---- CE --------- PE

             Traffic flow
            ---------->

  In the figure above, the management system should implement the
  classification rule:

  o  in the ingress direction on the PE interface, if the CE is
     customer-managed.

  o  in the ingress direction on the CE interface connected to the
     customer LAN, if the CE is provider-managed.

  The figure below describes a sample service description of QoS
  classification for a site:

    <?xml version="1.0"?>
    <l3vpn-svc xmlns="urn:ietf:params:xml:ns:yang:ietf-l3vpn-svc">
      <vpn-services>
        <vpn-service>
          <vpn-id>VPNA</vpn-id>
        </vpn-service>




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      </vpn-services>
      <sites>
        <site>
          <site-id>SITE1</site-id>
          <service>
            <qos>
              <qos-classification-policy>
                <rule>
                  <id>SvrA-http</id>
                  <match-flow>
                    <ipv4-src-prefix>192.0.2.0/24</ipv4-src-prefix>
                    <ipv4-dst-prefix>203.0.113.1/32</ipv4-dst-prefix>
                    <l4-dst-port>80</l4-dst-port>
                    <protocol-type>tcp</protocol-type>
                  </match-flow>
                  <target-class-id>DATA2</target-class-id>
                </rule>
                <rule>
                  <id>SvrA-ftp</id>
                  <match-flow>
                    <ipv4-src-prefix>192.0.2.0/24</ipv4-src-prefix>
                    <ipv4-dst-prefix>203.0.113.1/32</ipv4-dst-prefix>
                    <l4-dst-port>21</l4-dst-port>
                    <protocol-field>tcp</protocol-field>
                  </match-flow>
                  <target-class-id>DATA2</target-class-id>
                </rule>
                <rule>
                  <id>p2p</id>
                  <match-application>p2p</match-application>
                  <target-class-id>DATA3</target-class-id>
                </rule>
                <rule>
                  <id>any</id>
                  <target-class-id>DATA1</target-class-id>
                </rule>
              </qos-classification-policy>
            </qos>
          </service>
        </site>
      </sites>
    </l3vpn-svc>

  In the example above:

  o  HTTP traffic from the 192.0.2.0/24 LAN destined for 203.0.113.1/32
     will be classified in DATA2.




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  o  FTP traffic from the 192.0.2.0/24 LAN destined for 203.0.113.1/32
     will be classified in DATA2.

  o  Peer-to-peer traffic will be classified in DATA3.

  o  All other traffic will be classified in DATA1.

  The order of rule list entries is defined by the user.  The
  management system responsible for translating those rules in network
  element configuration MUST keep the same processing order in network
  element configuration.

6.12.3.2.  QoS Profile

  The user can choose either a standard profile provided by the
  operator or a custom profile.  The "qos-profile" container defines
  the traffic-scheduling policy to be used by the SP.

                                          Provider network
                                     +-----------------------+
           192.0.2.0/24
           198.51.100.0/24 ---- CE --------- PE
                                   \       /
                                  qos-profile

  A custom QoS profile is defined as a list of classes of services and
  associated properties.  The properties are as follows:

  o  direction: used to specify the direction to which the QoS profile
     is applied.  This model supports three direction settings: "Site-
     to-WAN", "WAN-to-Site", and "both".  By default, the "both"
     direction value is used.  If the direction is "both", the provider
     should ensure scheduling according to the requested policy in both
     traffic directions (SP to customer and customer to SP).  As an
     example, a device-scheduling policy may be implemented on both the
     PE side and the CE side of the WAN link.  If the direction is
     "WAN-to-Site", the provider should ensure scheduling from the SP
     network to the customer site.  As an example, a device-scheduling
     policy may be implemented only on the PE side of the WAN link
     towards the customer.

  o  rate-limit: used to rate-limit the class of service.  The value is
     expressed as a percentage of the global service bandwidth.  When
     the qos-profile container is implemented on the CE side,
     svc-output-bandwidth is taken into account as a reference.  When
     it is implemented on the PE side, svc-input-bandwidth is used.





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  o  latency: used to define the latency constraint of the class.  The
     latency constraint can be expressed as the lowest possible latency
     or a latency boundary expressed in milliseconds.  How this latency
     constraint will be fulfilled is up to the SP's implementation of
     the service: a strict priority queuing may be used on the access
     and in the core network, and/or a low-latency routing
     configuration may be created for this traffic class.

  o  jitter: used to define the jitter constraint of the class.  The
     jitter constraint can be expressed as the lowest possible jitter
     or a jitter boundary expressed in microseconds.  How this jitter
     constraint will be fulfilled is up to the SP's implementation of
     the service: a strict priority queuing may be used on the access
     and in the core network, and/or a jitter-aware routing
     configuration may be created for this traffic class.

  o  bandwidth: used to define a guaranteed amount of bandwidth for the
     class of service.  It is expressed as a percentage.  The
     "guaranteed-bw-percent" parameter uses available bandwidth as a
     reference.  When the qos-profile container is implemented on the
     CE side, svc-output-bandwidth is taken into account as a
     reference.  When it is implemented on the PE side, svc-input-
     bandwidth is used.  By default, the bandwidth reservation is only
     guaranteed at the access level.  The user can use the "end-to-end"
     leaf to request an end-to-end bandwidth reservation, including
     across the MPLS transport network.  (In other words, the SP will
     activate something in the MPLS core to ensure that the bandwidth
     request from the customer will be fulfilled by the MPLS core as
     well.)  How this is done (e.g., RSVP reservation, controller
     reservation) is out of scope for this document.

  In addition, due to network conditions, some constraints may not be
  completely fulfilled by the SP; in this case, the SP should advise
  the customer about the limitations.  How this communication is done
  is out of scope for this document.

  Example of service configuration using a standard QoS profile with
  the following corresponding XML snippet:

<?xml version="1.0"?>
<l3vpn-svc xmlns="urn:ietf:params:xml:ns:yang:ietf-l3vpn-svc">
<vpn-profiles>
 <valid-provider-identifiers>
  <qos-profile-identifier>
   <id>GOLD</id>
  </qos-profile-identifier>
  <qos-profile-identifier>
   <id>PLATINUM</id>



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  </qos-profile-identifier>
 </valid-provider-identifiers>
</vpn-profiles>
<vpn-services>
 <vpn-service>
  <vpn-id>VPNA</vpn-id>
 </vpn-service>
</vpn-services>
<sites>
 <site>
  <site-id>SITE1</site-id>
  <locations>
   <location>
    <location-id>L1</location-id>
   </location>
  </locations>
  <site-network-accesses>
   <site-network-access>
    <site-network-access-id>1245HRTFGJGJ154654</site-network-access-id>
    <vpn-attachment>
     <vpn-id>VPNA</vpn-id>
     <site-role>spoke-role</site-role>
    </vpn-attachment>
    <ip-connection>
     <ipv4>
      <address-allocation-type>provider-dhcp</address-allocation-type>
     </ipv4>
     <ipv6>
      <address-allocation-type>provider-dhcp</address-allocation-type>
     </ipv6>
    </ip-connection>
    <security>
     <encryption>
      <layer>layer3</layer>
     </encryption>
    </security>
    <location-reference>L1</location-reference>
    <service>
     <svc-input-bandwidth>100000000</svc-input-bandwidth>
     <svc-output-bandwidth>100000000</svc-output-bandwidth>
     <svc-mtu>1514</svc-mtu>
     <qos>
      <qos-profile>
       <profile>PLATINUM</profile>
      </qos-profile>
     </qos>
    </service>
   </site-network-access>



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   <site-network-access>
    <site-network-access-id>555555AAAA2344</site-network-access-id>
    <vpn-attachment>
     <vpn-id>VPNA</vpn-id>
     <site-role>spoke-role</site-role>
    </vpn-attachment>
    <ip-connection>
     <ipv4>
      <address-allocation-type>provider-dhcp</address-allocation-type>
     </ipv4>
     <ipv6>
      <address-allocation-type>provider-dhcp</address-allocation-type>
     </ipv6>
    </ip-connection>
    <security>
     <encryption>
      <layer>layer3</layer>
     </encryption>
    </security>
    <location-reference>L1</location-reference>
    <service>
     <svc-input-bandwidth>2000000</svc-input-bandwidth>
     <svc-output-bandwidth>2000000</svc-output-bandwidth>
     <svc-mtu>1514</svc-mtu>
     <qos>
      <qos-profile>
       <profile>GOLD</profile>
      </qos-profile>
     </qos>
    </service>
   </site-network-access>
  </site-network-accesses>
 </site>
</sites>
</l3vpn-svc>

  Example of service configuration using a custom QoS profile with the
  following corresponding XML snippet:

<?xml version="1.0"?>
<l3vpn-svc xmlns="urn:ietf:params:xml:ns:yang:ietf-l3vpn-svc">
 <vpn-profiles>
  <valid-provider-identifiers>
   <qos-profile-identifier>
    <id>GOLD</id>
   </qos-profile-identifier>
   <qos-profile-identifier>
    <id>PLATINUM</id>



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   </qos-profile-identifier>
  </valid-provider-identifiers>
 </vpn-profiles>
 <vpn-services>
  <vpn-service>
   <vpn-id>VPNA</vpn-id>
  </vpn-service>
 </vpn-services>
 <sites>
  <site>
   <site-id>SITE1</site-id>
   <locations>
    <location>
     <location-id>L1</location-id>
    </location>
   </locations>
   <site-network-accesses>
    <site-network-access>
     <site-network-access-id>Site1</site-network-access-id>
     <location-reference>L1</location-reference>
     <ip-connection>
      <ipv4>
       <address-allocation-type>provider-dhcp</address-allocation-type>
      </ipv4>
      <ipv6>
       <address-allocation-type>provider-dhcp</address-allocation-type>
      </ipv6>
     </ip-connection>
     <service>
      <svc-mtu>1514</svc-mtu>
      <svc-input-bandwidth>10000000</svc-input-bandwidth>
      <svc-output-bandwidth>10000000</svc-output-bandwidth>
     </service>
     <security>
      <encryption>
       <layer>layer3</layer>
      </encryption>
     </security>
     <location-reference>L1</location-reference>
     <vpn-attachment>
      <vpn-id>VPNA</vpn-id>
      <site-role>spoke-role</site-role>
     </vpn-attachment>
     <service>
      <svc-input-bandwidth>100000000</svc-input-bandwidth>
      <svc-output-bandwidth>100000000</svc-output-bandwidth>
      <qos>
       <qos-profile>



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        <classes>
         <class>
          <class-id>REAL_TIME</class-id>
          <direction>both</direction>
          <rate-limit>10</rate-limit>
          <latency>
           <use-lowest-latency/>
          </latency>
          <bandwidth>
           <guaranteed-bw-percent>80</guaranteed-bw-percent>
          </bandwidth>
         </class>
         <class>
          <class-id>DATA1</class-id>
          <latency>
           <latency-boundary>70</latency-boundary>
          </latency>
          <bandwidth>
           <guaranteed-bw-percent>80</guaranteed-bw-percent>
          </bandwidth>
         </class>
         <class>
          <class-id>DATA2</class-id>
          <latency>
           <latency-boundary>200</latency-boundary>
          </latency>
          <bandwidth>
           <guaranteed-bw-percent>5</guaranteed-bw-percent>
           <end-to-end/>
          </bandwidth>
         </class>
        </classes>
       </qos-profile>
      </qos>
     </service>
    </site-network-access>
   </site-network-accesses>
  </site>
 </sites>
</l3vpn-svc>

  The custom QoS profile for Site1 defines a REAL_TIME class with a
  latency constraint expressed as the lowest possible latency.  It also
  defines two data classes -- DATA1 and DATA2.  The two classes express
  a latency boundary constraint as well as a bandwidth reservation, as
  the REAL_TIME class is rate-limited to 10% of the service bandwidth
  (10% of 100 Mbps = 10 Mbps).  In cases where congestion occurs, the
  REAL_TIME traffic can go up to 10 Mbps (let's assume that only 5 Mbps



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  are consumed).  DATA1 and DATA2 will share the remaining bandwidth
  (95 Mbps) according to their percentage.  So, the DATA1 class will be
  served with at least 76 Mbps of bandwidth, while the DATA2 class will
  be served with at least 4.75 Mbps.  The latency boundary information
  of the data class may help the SP define a specific buffer tuning or
  a specific routing within the network.  The maximum percentage to be
  used is not limited by this model but MUST be limited by the
  management system according to the policies authorized by the SP.

6.12.4.  Multicast

  The "multicast" container defines the type of site in the customer
  multicast service topology: source, receiver, or both.  These
  parameters will help the management system optimize the multicast
  service.  Users can also define the type of multicast relationship
  with the customer: router (requires a protocol such as PIM), host
  (IGMP or MLD), or both.  An address family (IPv4, IPv6, or both) can
  also be defined.

































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6.13.  Enhanced VPN Features

6.13.1.  Carriers' Carriers

  In the case of CsC [RFC4364], a customer may want to build an MPLS
  service using an IP VPN to carry its traffic.

                 LAN customer1
                     |
                     |
                    CE1
                     |
                     | -------------
                  (vrf_cust1)
                   CE1_ISP1
                     |                 ISP1 POP
                     | MPLS link
                     | -------------
                     |
                  (vrf ISP1)
                    PE1

                   (...)               Provider backbone

                    PE2
                   (vrf ISP1)
                     |
                     | ------------
                     |
                     | MPLS link
                     |                 ISP1 POP
                    CE2_ISP1
                    (vrf_cust1)
                     | ------------
                     |
                    CE2
                     |
                  LAN customer1

  In the figure above, ISP1 resells an IP VPN service but has no core
  network infrastructure between its POPs.  ISP1 uses an IP VPN as the
  core network infrastructure (belonging to another provider) between
  its POPs.








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  In order to support CsC, the VPN service must indicate MPLS support
  by setting the "carrierscarrier" leaf to true in the vpn-service
  list.  The link between CE1_ISP1/PE1 and CE2_ISP1/PE2 must also run
  an MPLS signalling protocol.  This configuration is done at the site
  level.

  In the proposed model, LDP or BGP can be used as the MPLS signalling
  protocol.  In the case of LDP, an IGP routing protocol MUST also be
  activated.  In the case of BGP signalling, BGP MUST also be
  configured as the routing protocol.

  If CsC is enabled, the requested "svc-mtu" leaf will refer to the
  MPLS MTU and not to the IP MTU.

6.14.  External ID References

  The service model sometimes refers to external information through
  identifiers.  As an example, to order a cloud-access to a particular
  cloud service provider (CSP), the model uses an identifier to refer
  to the targeted CSP.  If a customer is directly using this service
  model as an API (through REST or NETCONF, for example) to order a
  particular service, the SP should provide a list of authorized
  identifiers.  In the case of cloud-access, the SP will provide the
  associated identifiers for each available CSP.  The same applies to
  other identifiers, such as std-qos-profile, OAM profile-name, and
  provider-profile for encryption.

  How an SP provides the meanings of those identifiers to the customer
  is out of scope for this document.

6.15.  Defining NNIs

  An autonomous system (AS) is a single network or group of networks
  that is controlled by a common system administration group and that
  uses a single, clearly defined routing protocol.  In some cases, VPNs
  need to span different ASes in different geographic areas or span
  different SPs.  The connection between ASes is established by the SPs
  and is seamless to the customer.  Examples include

  o  a partnership between SPs (e.g., carrier, cloud) to extend their
     VPN service seamlessly.

  o  an internal administrative boundary within a single SP (e.g.,
     backhaul versus core versus data center).

  NNIs (network-to-network interfaces) have to be defined to extend the
  VPNs across multiple ASes.




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  [RFC4364] defines multiple flavors of VPN NNI implementations.  Each
  implementation has pros and cons; this topic is outside the scope of
  this document.  For example, in an Inter-AS option A, autonomous
  system border router (ASBR) peers are connected by multiple
  interfaces with at least one of those interfaces spanning the two
  ASes while being present in the same VPN.  In order for these ASBRs
  to signal unlabeled IP prefixes, they associate each interface with a
  VPN routing and forwarding (VRF) instance and a Border Gateway
  Protocol (BGP) session.  As a result, traffic between the back-to-
  back VRFs is IP.  In this scenario, the VPNs are isolated from each
  other, and because the traffic is IP, QoS mechanisms that operate on
  IP traffic can be applied to achieve customer service level
  agreements (SLAs).

    --------                 --------------              -----------
   /        \               /              \            /           \
  | Cloud    |             |                |          |             |
  | Provider |-----NNI-----|                |----NNI---| Data Center |
  |  #1      |             |                |          |             |
   \        /              |                |           \           /
    --------               |                |            -----------
                           |                |
    --------               |   My network   |           -----------
   /        \              |                |          /           \
  | Cloud    |             |                |         |             |
  | Provider |-----NNI-----|                |---NNI---|  L3VPN      |
  |  #2      |             |                |         |  Partner    |
   \        /              |                |         |             |
    --------               |                |         |             |
                            \              /          |             |
                             --------------            \           /
                                   |                    -----------
                                   |
                                  NNI
                                   |
                                   |
                           -------------------
                          /                   \
                         |                     |
                         |                     |
                         |                     |
                         |     L3VPN Partner   |
                         |                     |
                          \                   /
                           -------------------






Wu, et al.                   Standards Track                  [Page 106]

RFC 8299       YANG Data Model for L3VPN Service Delivery   January 2018


  The figure above describes an SP network called "My network" that has
  several NNIs.  This network uses NNIs to:

  o  increase its footprint by relying on L3VPN partners.

  o  connect its own data center services to the customer IP VPN.

  o  enable the customer to access its private resources located in a
     private cloud owned by some CSPs.

6.15.1.  Defining an NNI with the Option A Flavor

            AS A                                          AS B
     -------------------                         -------------------
    /                   \                       /                   \
   |                     |                     |                     |
   |                 ++++++++ Inter-AS link ++++++++                 |
   |                 +      +_______________+      +                 |
   |                 +  (VRF1)---(VPN1)----(VRF1)  +                 |
   |                 + ASBR +               + ASBR +                 |
   |                 +  (VRF2)---(VPN2)----(VRF2)  +                 |
   |                 +      +_______________+      +                 |
   |                 ++++++++               ++++++++                 |
   |                     |                     |                     |
   |                     |                     |                     |
   |                     |                     |                     |
   |                 ++++++++ Inter-AS link ++++++++                 |
   |                 +      +_______________+      +                 |
   |                 +  (VRF1)---(VPN1)----(VRF1)  +                 |
   |                 + ASBR +               + ASBR +                 |
   |                 +  (VRF2)---(VPN2)----(VRF2)  +                 |
   |                 +      +_______________+      +                 |
   |                 ++++++++               ++++++++                 |
   |                     |                     |                     |
   |                     |                     |                     |
    \                   /                       \                   /
     -------------------                         -------------------

  In option A, the two ASes are connected to each other with physical
  links on ASBRs.  For resiliency purposes, there may be multiple
  physical connections between the ASes.  A VPN connection -- physical
  or logical (on top of physical) -- is created for each VPN that needs
  to cross the AS boundary, thus providing a back-to-back VRF model.

  From a service model's perspective, this VPN connection can be seen
  as a site.  Let's say that AS B wants to extend some VPN connections
  for VPN C on AS A.  The administrator of AS B can use this service
  model to order a site on AS A.  All connection scenarios could be



Wu, et al.                   Standards Track                  [Page 107]

RFC 8299       YANG Data Model for L3VPN Service Delivery   January 2018


  realized using the features of the current model.  As an example, the
  figure above shows two physical connections that have logical
  connections per VPN overlaid on them.  This could be seen as a dual-
  homed subVPN scenario.  Also, the administrator of AS B will be able
  to choose the appropriate routing protocol (e.g., E-BGP) to
  dynamically exchange routes between ASes.

  This document assumes that the option A NNI flavor SHOULD reuse the
  existing VPN site modeling.

  Example: a customer wants its CSP A to attach its virtual network N
  to an existing IP VPN (VPN1) that he has from L3VPN SP B.

          CSP A                              L3VPN SP B

    -----------------                    -------------------
   /                 \                  /                   \
  |       |           |                |                     |
  |  VM --|       ++++++++  NNI    ++++++++                  |--- VPN1
  |       |       +      +_________+      +                  |   Site#1
  |       |--------(VRF1)---(VPN1)--(VRF1)+                  |
  |       |       + ASBR +         + ASBR +                  |
  |       |       +      +_________+      +                  |
  |       |       ++++++++         ++++++++                  |
  |  VM --|           |                |                     |--- VPN1
  |       |Virtual    |                |                     |   Site#2
  |       |Network    |                |                     |
  |  VM --|           |                |                     |--- VPN1
  |       |           |                |                     |   Site#3
   \                 /                  \                   /
    -----------------                    -------------------
                                                 |
                                                 |
                                               VPN1
                                              Site#4

  To create the VPN connectivity, the CSP or the customer may use the
  L3VPN service model that SP B exposes.  We could consider that, as
  the NNI is shared, the physical connection (bearer) between CSP A and
  SP B already exists.  CSP A may request through a service model the
  creation of a new site with a single site-network-access (single-
  homing is used in the figure).  As a placement constraint, CSP A may
  use the existing bearer reference it has from SP A to force the
  placement of the VPN NNI on the existing link.  The XML snippet below
  illustrates a possible configuration request to SP B:






Wu, et al.                   Standards Track                  [Page 108]

RFC 8299       YANG Data Model for L3VPN Service Delivery   January 2018


<?xml version="1.0"?>
<l3vpn-svc xmlns="urn:ietf:params:xml:ns:yang:ietf-l3vpn-svc">
<vpn-profiles>
 <valid-provider-identifiers>
  <qos-profile-identifier>
   <id>GOLD</id>
  </qos-profile-identifier>
  <qos-profile-identifier>
   <id>PLATINUM</id>
  </qos-profile-identifier>
 </valid-provider-identifiers>
</vpn-profiles>
<vpn-services>
 <vpn-service>
  <vpn-id>VPN1</vpn-id>
 </vpn-service>
</vpn-services>
<sites>
 <site>
  <site-id>CSP_A_attachment</site-id>
  <security>
   <encryption>
    <layer>layer3</layer>
   </encryption>
  </security>
  <locations>
   <location>
    <location-id>L1</location-id>
   </location>
  </locations>
  <locations>
   <location>
    <location-id>1</location-id>
    <city>NY</city>
    <country-code>US</country-code>
   </location>
  </locations>
  <site-vpn-flavor>site-vpn-flavor-nni</site-vpn-flavor>
  <routing-protocols>
   <routing-protocol>
    <type>bgp</type>
    <bgp>
     <autonomous-system>500</autonomous-system>
     <address-family>ipv4</address-family>
    </bgp>
   </routing-protocol>
  </routing-protocols>
  <site-network-accesses>



Wu, et al.                   Standards Track                  [Page 109]

RFC 8299       YANG Data Model for L3VPN Service Delivery   January 2018


   <site-network-access>
    <site-network-access-id>CSP_A_VN1</site-network-access-id>
    <location-reference>L1</location-reference>
    <ip-connection>
     <ipv4>
      <address-allocation-type>provider-dhcp</address-allocation-type>
     </ipv4>
     <ipv6>
      <address-allocation-type>provider-dhcp</address-allocation-type>
     </ipv6>
    </ip-connection>
    <ip-connection>
     <ipv4>
      <address-allocation-type>static-address</address-allocation-type>
      <addresses>
       <provider-address>203.0.113.1</provider-address>
       <customer-address>203.0.113.2</customer-address>
       <prefix-length>30</prefix-length>
      </addresses>
     </ipv4>
    </ip-connection>
    <service>
     <svc-input-bandwidth>450000000</svc-input-bandwidth>
     <svc-output-bandwidth>450000000</svc-output-bandwidth>
     <svc-mtu>1514</svc-mtu>
    </service>
    <security>
     <encryption>
      <layer>layer3</layer>
     </encryption>
    </security>
    <vpn-attachment>
     <vpn-id>VPN1</vpn-id>
     <site-role>any-to-any-role</site-role>
    </vpn-attachment>
   </site-network-access>
  </site-network-accesses>
  <management>
   <type>customer-managed</type>
  </management>
 </site>
</sites>
</l3vpn-svc>

  The case described above is different from a scenario using the
  cloud-accesses container, as the cloud-access provides a public cloud
  access while this example enables access to private resources located
  in a CSP network.



Wu, et al.                   Standards Track                  [Page 110]

RFC 8299       YANG Data Model for L3VPN Service Delivery   January 2018


6.15.2.  Defining an NNI with the Option B Flavor

           AS A                                          AS B
     -------------------                         -------------------
    /                   \                       /                   \
   |                     |                     |                     |
   |                 ++++++++ Inter-AS link ++++++++                 |
   |                 +      +_______________+      +                 |
   |                 +      +               +      +                 |
   |                 + ASBR +<---MP-BGP---->+ ASBR +                 |
   |                 +      +               +      +                 |
   |                 +      +_______________+      +                 |
   |                 ++++++++               ++++++++                 |
   |                     |                     |                     |
   |                     |                     |                     |
   |                     |                     |                     |
   |                 ++++++++ Inter-AS link ++++++++                 |
   |                 +      +_______________+      +                 |
   |                 +      +               +      +                 |
   |                 + ASBR +<---MP-BGP---->+ ASBR +                 |
   |                 +      +               +      +                 |
   |                 +      +_______________+      +                 |
   |                 ++++++++               ++++++++                 |
   |                     |                     |                     |
   |                     |                     |                     |
    \                   /                       \                   /
     -------------------                         -------------------

  In option B, the two ASes are connected to each other with physical
  links on ASBRs.  For resiliency purposes, there may be multiple
  physical connections between the ASes.  The VPN "connection" between
  ASes is done by exchanging VPN routes through MP-BGP [RFC4760].

  There are multiple flavors of implementations of such an NNI.  For
  example:

  1.  The NNI is internal to the provider and is situated between a
      backbone and a data center.  There is enough trust between the
      domains to not filter the VPN routes.  So, all the VPN routes are
      exchanged.  RT filtering may be implemented to save some
      unnecessary route states.

  2.  The NNI is used between providers that agreed to exchange VPN
      routes for specific RTs only.  Each provider is authorized to use
      the RT values from the other provider.






Wu, et al.                   Standards Track                  [Page 111]

RFC 8299       YANG Data Model for L3VPN Service Delivery   January 2018


  3.  The NNI is used between providers that agreed to exchange VPN
      routes for specific RTs only.  Each provider has its own RT
      scheme.  So, a customer spanning the two networks will have
      different RTs in each network for a particular VPN.

  Case 1 does not require any service modeling, as the protocol enables
  the dynamic exchange of necessary VPN routes.

  Case 2 requires that an RT-filtering policy on ASBRs be maintained.
  From a service modeling point of view, it is necessary to agree on
  the list of RTs to authorize.

  In Case 3, both ASes need to agree on the VPN RT to exchange, as well
  as how to map a VPN RT from AS A to the corresponding RT in AS B (and
  vice versa).

  Those modelings are currently out of scope for this document.

         CSP A                               L3VPN SP B

    -----------------                    ------------------
   /                 \                  /                  \
  |       |           |                |                    |
  |  VM --|       ++++++++   NNI    ++++++++                |--- VPN1
  |       |       +      +__________+      +                |   Site#1
  |       |-------+      +          +      +                |
  |       |       + ASBR +<-MP-BGP->+ ASBR +                |
  |       |       +      +__________+      +                |
  |       |       ++++++++          ++++++++                |
  |  VM --|           |                |                    |--- VPN1
  |       |Virtual    |                |                    |   Site#2
  |       |Network    |                |                    |
  |  VM --|           |                |                    |--- VPN1
  |       |           |                |                    |   Site#3
   \                 /                 |                    |
    -----------------                  |                    |
                                        \                  /
                                         ------------------
                                                  |
                                                  |
                                                 VPN1
                                                Site#4

  The example above describes an NNI connection between CSP A and SP
  network B.  Both SPs do not trust themselves and use a different RT
  allocation policy.  So, in terms of implementation, the customer VPN
  has a different RT in each network (RT A in CSP A and RT B in SP
  network B).  In order to connect the customer virtual network in CSP



Wu, et al.                   Standards Track                  [Page 112]

RFC 8299       YANG Data Model for L3VPN Service Delivery   January 2018


  A to the customer IP VPN (VPN1) in SP network B, CSP A should request
  that SP network B open the customer VPN on the NNI (accept the
  appropriate RT).  Who does the RT translation depends on the
  agreement between the two SPs: SP B may permit CSP A to request VPN
  (RT) translation.

6.15.3.  Defining an NNI with the Option C Flavor

           AS A                                           AS B
    -------------------                          -------------------
   /                   \                        /                   \
  |                     |                      |                     |
  |                     |                      |                     |
  |                     |                      |                     |
  |                 ++++++++ Multihop E-BGP ++++++++                 |
  |                 +      +                +      +                 |
  |                 +      +                +      +                 |
  |                 + RGW  +<----MP-BGP---->+ RGW  +                 |
  |                 +      +                +      +                 |
  |                 +      +                +      +                 |
  |                 ++++++++                ++++++++                 |
  |                     |                      |                     |
  |                     |                      |                     |
  |                     |                      |                     |
  |                     |                      |                     |
  |                     |                      |                     |
  |                 ++++++++ Inter-AS link ++++++++                  |
  |                 +      +_______________+      +                  |
  |                 +      +               +      +                  |
  |                 + ASBR +               + ASBR +                  |
  |                 +      +               +      +                  |
  |                 +      +_______________+      +                  |
  |                 ++++++++               ++++++++                  |
  |                     |                      |                     |
  |                     |                      |                     |
  |                     |                      |                     |
  |                 ++++++++ Inter-AS link ++++++++                  |
  |                 +      +_______________+      +                  |
  |                 +      +               +      +                  |
  |                 + ASBR +               + ASBR +                  |
  |                 +      +               +      +                  |
  |                 +      +_______________+      +                  |
  |                 ++++++++               ++++++++                  |
  |                     |                      |                     |
  |                     |                      |                     |
   \                   /                        \                   /
    -------------------                          -------------------




Wu, et al.                   Standards Track                  [Page 113]

RFC 8299       YANG Data Model for L3VPN Service Delivery   January 2018


  From a VPN service's perspective, the option C NNI is very similar to
  option B, as an MP-BGP session is used to exchange VPN routes between
  the ASes.  The difference is that the forwarding plane and the
  control plane are on different nodes, so the MP-BGP session is
  multihop between routing gateway (RGW) nodes.

  From a VPN service's point of view, modeling options B and C will be
  identical.

7.  Service Model Usage Example

  As explained in Section 5, this service model is intended to be
  instantiated at a management layer and is not intended to be used
  directly on network elements.  The management system serves as a
  central point of configuration of the overall service.

  This section provides an example of how a management system can use
  this model to configure an IP VPN service on network elements.

  In this example, we want to achieve the provisioning of a VPN service
  for three sites using a Hub-and-Spoke VPN service topology.  One of
  the sites will be dual-homed, and load-sharing is expected.

     +-------------------------------------------------------------+
     |   Hub_Site  ------ PE1               PE2 ------ Spoke_Site1 |
     |      |                   +----------------------------------+
     |      |                   |
     |      |                   +----------------------------------+
     |   Hub_Site  ------ PE3               PE4 ------ Spoke_Site2 |
     +-------------------------------------------------------------+

  The following XML snippet describes the overall simplified service
  configuration of this VPN.


















Wu, et al.                   Standards Track                  [Page 114]

RFC 8299       YANG Data Model for L3VPN Service Delivery   January 2018


     <?xml version="1.0"?>
     <l3vpn-svc xmlns="urn:ietf:params:xml:ns:yang:ietf-l3vpn-svc">
       <vpn-profiles>
         <valid-provider-identifiers>
           <qos-profile-identifier>
             <id>GOLD</id>
           </qos-profile-identifier>
           <qos-profile-identifier>
             <id>PLATINUM</id>
           </qos-profile-identifier>
         </valid-provider-identifiers>
       </vpn-profiles>
       <vpn-services>
         <vpn-service>
           <vpn-id>12456487</vpn-id>
           <vpn-service-topology>hub-spoke</vpn-service-topology>
         </vpn-service>
       </vpn-services>
     </l3vpn-svc>

  When receiving the request for provisioning the VPN service, the
  management system will internally (or through communication with
  another OSS component) allocate VPN RTs.  In this specific case, two
  RTs will be allocated (100:1 for Hub and 100:2 for Spoke).  The
  output of corresponding XML snippet below describes the configuration
  of Spoke_Site1.

<?xml version="1.0"?>
<l3vpn-svc xmlns="urn:ietf:params:xml:ns:yang:ietf-l3vpn-svc">
<vpn-profiles>
 <valid-provider-identifiers>
  <qos-profile-identifier>
   <id>GOLD</id>
  </qos-profile-identifier>
  <qos-profile-identifier>
   <id>PLATINUM</id>
  </qos-profile-identifier>
 </valid-provider-identifiers>
</vpn-profiles>
<vpn-services>
 <vpn-service>
  <vpn-id>12456487</vpn-id>
  <vpn-service-topology>hub-spoke</vpn-service-topology>
 </vpn-service>
</vpn-services>
<sites>
 <site>
  <site-id>Spoke_Site1</site-id>



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RFC 8299       YANG Data Model for L3VPN Service Delivery   January 2018


  <devices>
   <device>
    <device-id>D1</device-id>
   </device>
  </devices>
  <locations>
   <location>
    <location-id>1</location-id>
    <city>NY</city>
    <country-code>US</country-code>
   </location>
  </locations>
  <security>
   <encryption>
    <layer>layer3</layer>
   </encryption>
  </security>
  <routing-protocols>
   <routing-protocol>
    <type>bgp</type>
    <bgp>
     <autonomous-system>500</autonomous-system>
     <address-family>ipv4</address-family>
     <address-family>ipv6</address-family>
    </bgp>
   </routing-protocol>
  </routing-protocols>
  <site-network-accesses>
   <site-network-access>
    <site-network-access-id>Spoke_Site1</site-network-access-id>
    <device-reference>D1</device-reference>
    <access-diversity>
     <groups>
      <group>
       <group-id>20</group-id>
      </group>
     </groups>
     <constraints>
      <constraint>
       <constraint-type>pe-diverse</constraint-type>
       <target>
        <group>
         <group-id>10</group-id>
        </group>
       </target>
      </constraint>
     </constraints>
    </access-diversity>



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RFC 8299       YANG Data Model for L3VPN Service Delivery   January 2018


    <ip-connection>
     <ipv4>
      <address-allocation-type>static-address</address-allocation-type>
      <addresses>
       <provider-address>203.0.113.254</provider-address>
       <customer-address>203.0.113.2</customer-address>
       <prefix-length>24</prefix-length>
      </addresses>
     </ipv4>
     <ipv6>
      <address-allocation-type>static-address</address-allocation-type>
      <addresses>
       <provider-address>2001:db8::1</provider-address>
       <customer-address>2001:db8::2</customer-address>
       <prefix-length>64</prefix-length>
      </addresses>
     </ipv6>
    </ip-connection>
    <service>
     <svc-input-bandwidth>450000000</svc-input-bandwidth>
     <svc-output-bandwidth>450000000</svc-output-bandwidth>
     <svc-mtu>1514</svc-mtu>
    </service>
    <security>
     <encryption>
      <layer>layer3</layer>
     </encryption>
    </security>
    <vpn-attachment>
     <vpn-id>12456487</vpn-id>
     <site-role>spoke-role</site-role>
    </vpn-attachment>
   </site-network-access>
  </site-network-accesses>
  <management>
   <type>provider-managed</type>
  </management>
 </site>
</sites>
</l3vpn-svc>

  When receiving the request for provisioning Spoke_Site1, the
  management system MUST allocate network resources for this site.  It
  MUST first determine the target network elements to provision the
  access, particularly the PE router (and perhaps also an aggregation
  switch).  As described in Section 6.6, the management system SHOULD
  use the location information and MUST use the access-diversity
  constraint to find the appropriate PE.  In this case, we consider



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RFC 8299       YANG Data Model for L3VPN Service Delivery   January 2018


  that Spoke_Site1 requires PE diversity with the Hub and that the
  management system allocates PEs based on the least distance.  Based
  on the location information, the management system finds the
  available PEs in the area nearest the customer and picks one that
  fits the access-diversity constraint.

  When the PE is chosen, the management system needs to allocate
  interface resources on the node.  One interface is selected from the
  pool of available PEs.  The management system can start provisioning
  the chosen PE node via whatever means the management system prefers
  (e.g., NETCONF, CLI).  The management system will check to see if a
  VRF that fits its needs is already present.  If not, it will
  provision the VRF: the RD will be derived from the internal
  allocation policy model, and the RTs will be derived from the VPN
  policy configuration of the site (the management system allocated
  some RTs for the VPN).  As the site is a Spoke site (site-role), the
  management system knows which RTs must be imported and exported.  As
  the site is provider-managed, some management RTs may also be added
  (100:5000).  Standard provider VPN policies MAY also be added in the
  configuration.

  Example of generated PE configuration:

  ip vrf Customer1
   export-map STD-CUSTOMER-EXPORT      <---- Standard SP configuration
   route-distinguisher 100:3123234324
   route-target import 100:1
   route-target import 100:5000        <---- Standard SP configuration
   route-target export 100:2                    for provider-managed CE
  !

  When the VRF has been provisioned, the management system can start
  configuring the access on the PE using the allocated interface
  information.  IP addressing is chosen by the management system.  One
  address will be picked from an allocated subnet for the PE, and
  another will be used for the CE configuration.  Routing protocols
  will also be configured between the PE and CE; because this model is
  provider-managed, the choices are left to the SP.  BGP was chosen for
  this example.  This choice is independent of the routing protocol
  chosen by the customer.  BGP will be used to configure the CE-to-LAN
  connection as requested in the service model.  Peering addresses will
  be derived from those of the connection.  As the CE is provider-
  managed, the CE's AS number can be automatically allocated by the
  management system.  Standard configuration templates provided by the
  SP may also be added.






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  Example of generated PE configuration:

  interface Ethernet1/1/0.10
   encapsulation dot1q 10
   ip vrf forwarding Customer1
   ip address 198.51.100.1 255.255.255.252 <---- Comes from
                                                  automated allocation
   ipv6 address 2001:db8::10:1/64
   ip access-group STD-PROTECT-IN     <---- Standard SP config
  !
  router bgp 100
   address-family ipv4 vrf Customer1
    neighbor 198.51.100.2 remote-as 65000   <---- Comes from
                                                   automated allocation
    neighbor 198.51.100.2 route-map STD in  <---- Standard SP config
    neighbor 198.51.100.2 filter-list 10 in <---- Standard SP config
  !
   address-family ipv6 vrf Customer1
    neighbor 2001:db8::0a10:2 remote-as 65000   <---- Comes from
                                                   automated allocation
    neighbor 2001:db8::0a10:2 route-map STD in  <---- Standard SP
                                                         config
    neighbor 2001:db8::0a10:2 filter-list 10 in <---- Standard SP
                                                         config
  !
  ip route vrf Customer1 192.0.2.1 255.255.255.255 198.51.100.2
  ! Static route for provider administration of CE
  !

  As the CE router is not reachable at this stage, the management
  system can produce a complete CE configuration that can be manually
  uploaded to the node before sending the CE configuration to the
  customer premises.  The CE configuration will be built in the same
  way as the PE would be configured.  Based on the CE type (vendor/
  model) allocated to the customer as well as the bearer information,
  the management system knows which interface must be configured on the
  CE.  PE-CE link configuration is expected to be handled automatically
  using the SP OSS, as both resources are managed internally.  CE-to-
  LAN-interface parameters such as IP addressing are derived from the
  ip-connection container, taking into account how the management
  system distributes addresses between the PE and CE within the subnet.
  This will allow a plug-and-play configuration for the CE to be
  created.








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  Example of generated CE configuration:

  interface Loopback10
   description "Administration"
   ip address 192.0.2.1 255.255.255.255
  !
  interface FastEthernet10
   description "WAN"
   ip address 198.51.100.2 255.255.255.252 <---- Comes from
                                                  automated allocation
   ipv6 address 2001:db8::0a10:2/64
  !
  interface FastEthernet11
   description "LAN"
   ip address 203.0.113.254 255.255.255.0 <---- Comes from the
                                              ip-connection container
   ipv6 address 2001:db8::1/64
  !
  router bgp 65000
   address-family ipv4
    redistribute static route-map STATIC2BGP <---- Standard SP
                                                      configuration
    neighbor 198.51.100.1 remote-as 100     <---- Comes from
                                                automated allocation
    neighbor 203.0.113.2 remote-as 500     <---- Comes from the
                                                ip-connection container
   address-family ipv6
    redistribute static route-map STATIC2BGP <---- Standard SP
                                                      configuration
    neighbor 2001:db8::0a10:1 remote-as 100     <---- Comes from
                                                automated allocation
    neighbor 2001:db8::2 remote-as 500     <---- Comes from the
                                                ip-connection container
  !
  route-map STATIC2BGP permit 10
   match tag 10
  !

8.  Interaction with Other YANG Models

  As expressed in Section 5, this service model is intended to be
  instantiated in a management system and not directly on network
  elements.








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  The management system's role will be to configure the network
  elements.  The management system may be modular, so the component
  instantiating the service model (let's call it "service component")
  and the component responsible for network element configuration
  (let's call it "configuration component") may be different.

            l3vpn-svc         |
              Model           |
                              |
                   +---------------------+
                   |  Service component  | Service datastore
                   +---------------------+
                              |
                              |
                   +---------------------+
              +----|  Config component   |------+
             /     +---------------------+       \   Network
            /            /            \           \  Configuration
           /            /              \           \ models
          /            /                \           \
  ++++++++         ++++++++           ++++++++       ++++++++
  + CE A + ------- + PE A +           + PE B + ----- + CE B + Config
  ++++++++         ++++++++           ++++++++       ++++++++ datastore

           Site A                              Site B

  In the previous sections, we provided some examples of the
  translation of service provisioning requests to router configuration
  lines.  In the NETCONF/YANG ecosystem, we expect NETCONF/YANG to be
  used between the configuration component and network elements to
  configure the requested services on those elements.

  In this framework, specifications are expected to provide specific
  YANG modeling of service components on network elements.  There will
  be a strong relationship between the abstracted view provided by this
  service model and the detailed configuration view that will be
  provided by specific configuration models for network elements.

  The authors of this document anticipate definitions of YANG modules
  for the network elements listed below.  Note that this list is not
  exhaustive:

  o  VRF definition, including VPN policy expression.

  o  Physical interface.

  o  IP layer (IPv4, IPv6).




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  o  QoS: classification, profiles, etc.

  o  Routing protocols: support of configuration of all protocols
     listed in the document, as well as routing policies associated
     with those protocols.

  o  Multicast VPN.

  o  Network address translation.

  Example of a corresponding XML snippet with a VPN site request at the
  service level, using this model:

<?xml version="1.0"?>
<l3vpn-svc xmlns="urn:ietf:params:xml:ns:yang:ietf-l3vpn-svc">
<vpn-profiles>
 <valid-provider-identifiers>
  <qos-profile-identifier>
   <id>GOLD</id>
  </qos-profile-identifier>
  <qos-profile-identifier>
   <id>PLATINUM</id>
  </qos-profile-identifier>
 </valid-provider-identifiers>
</vpn-profiles>
<vpn-services>
 <vpn-service>
  <vpn-id>VPN1</vpn-id>
  <vpn-service-topology>hub-spoke</vpn-service-topology>
 </vpn-service>
</vpn-services>
<sites>
 <site>
  <site-id>Site A</site-id>
  <security>
   <encryption>
    <layer>layer3</layer>
   </encryption>
  </security>
  <locations>
   <location>
    <location-id>L1</location-id>
   </location>
  </locations>
  <site-network-accesses>
   <site-network-access>
    <site-network-access-id>1</site-network-access-id>
    <ip-connection>



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RFC 8299       YANG Data Model for L3VPN Service Delivery   January 2018


     <ipv4>
      <address-allocation-type>static-address</address-allocation-type>
      <addresses>
       <provider-address>203.0.113.254</provider-address>
       <customer-address>203.0.113.2</customer-address>
       <prefix-length>24</prefix-length>
      </addresses>
     </ipv4>
     <ipv6>
      <address-allocation-type>provider-dhcp</address-allocation-type>
     </ipv6>
    </ip-connection>
    <service>
     <svc-mtu>1514</svc-mtu>
     <svc-input-bandwidth>10000000</svc-input-bandwidth>
     <svc-output-bandwidth>10000000</svc-output-bandwidth>
    </service>
    <location-reference>L1</location-reference>
    <vpn-attachment>
     <vpn-policy-id>VPNPOL1</vpn-policy-id>
    </vpn-attachment>
   </site-network-access>
  </site-network-accesses>
  <routing-protocols>
   <routing-protocol>
    <type>static</type>
    <static>
     <cascaded-lan-prefixes>
      <ipv4-lan-prefixes>
       <lan>198.51.100.0/30</lan>
       <next-hop>203.0.113.2</next-hop>
      </ipv4-lan-prefixes>
     </cascaded-lan-prefixes>
    </static>
   </routing-protocol>
  </routing-protocols>
  <management>
   <type>customer-managed</type>
  </management>
  <vpn-policies>
   <vpn-policy>
    <vpn-policy-id>VPNPOL1</vpn-policy-id>
    <entries>
     <id>1</id>
     <vpn>
      <vpn-id>VPN1</vpn-id>
      <site-role>any-to-any-role</site-role>
     </vpn>



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    </entries>
   </vpn-policy>
  </vpn-policies>
 </site>
</sites>
</l3vpn-svc>

  In the service example above, the service component is expected to
  request that the configuration component of the management system
  provide the configuration of the service elements.  If we consider
  that the service component selected a PE (PE A) as the target PE for
  the site, the configuration component will need to push the
  configuration to PE A.  The configuration component will use several
  YANG data models to define the configuration to be applied to PE A.
  The XML snippet configuration of PE A might look like this:

<if:interfaces>
<if:interface>
 <if:name>eth0</if:name>
 <if:type>ianaift:ethernetCsmacd</if:type>
 <if:description>
  Link to CE A.
 </if:description>
 <ip:ipv4>
  <ip:address>
   <ip:ip>203.0.113.254</ip:ip>
   <ip:prefix-length>24</ip:prefix-length>
  </ip:address>
  <ip:forwarding>true</ip:forwarding>
 </ip:ipv4>
</if:interface>
</if:interfaces>
<rt:routing>
<rt:routing-instance>
 <rt:name>VRF_CustA</rt:name>
 <rt:type>l3vpn-network:vrf</rt:type>
 <rt:description>VRF for Customer A</rt:description>
 <l3vpn-network:rd>100:1546542343</l3vpn-network:rd>
 <l3vpn-network:import-rt>100:1</l3vpn-network:import-rt>
 <l3vpn-network:export-rt>100:1</l3vpn-network:export-rt>
 <rt:interfaces>
  <rt:interface>
   <rt:name>eth0</rt:name>
  </rt:interface>
 </rt:interfaces>
 <rt:routing-protocols>
  <rt:routing-protocol>
   <rt:type>rt:static</rt:type>



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   <rt:name>st0</rt:name>
   <rt:static-routes>
    <v4ur:ipv4>
     <v4ur:route>
     <v4ur:destination-prefix>198.51.100.0/30</v4ur:destination-prefix>
      <v4ur:next-hop>
       <v4ur:next-hop-address>203.0.113.2</v4ur:next-hop-address>
      </v4ur:next-hop>
     </v4ur:route>
    </v4ur:ipv4>
   </rt:static-routes>
  </rt:routing-protocol>
 </rt:routing-protocols>
</rt:routing-instance>
</rt:routing>

9.  YANG Module

<CODE BEGINS>file "[email protected]"
module ietf-l3vpn-svc {
 yang-version 1.1;
 namespace "urn:ietf:params:xml:ns:yang:ietf-l3vpn-svc";
 prefix l3vpn-svc;
 import ietf-inet-types {
  prefix inet;
 }
 import ietf-yang-types {
  prefix yang;
 }
 import ietf-netconf-acm {
  prefix nacm;
 }
 organization
  "IETF L3SM Working Group";
 contact
  "WG List: <mailto:[email protected]>
   Editor:
    L3SM WG
   Chairs:
    Adrian Farrel, Qin Wu
  ";
 description
 "This YANG module defines a generic service configuration
 model for Layer 3 VPNs. This model is common across all
 vendor implementations.






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 Copyright (c) 2018 IETF Trust and the persons
 identified as authors of the code.  All rights reserved.

 Redistribution and use in source and binary forms, with or
 without modification, is permitted pursuant to, and subject
 to the license terms contained in, the Simplified BSD License
 set forth in Section 4.c of the IETF Trust's Legal Provisions
 Relating to IETF Documents
 (https://trustee.ietf.org/license-info).

 This version of this YANG module is part of RFC 8299; see
 the RFC itself for full legal notices.";

 revision 2018-01-19 {
  description
   "Revision of RFC 8049 to fix implementation issues.";
  reference
   "RFC 8299";
  }
 revision 2017-01-27 {
  description
  "Initial document.";
  reference
    "RFC 8049.";
  }
 /* Features */
 feature cloud-access {
  description
  "Allows the VPN to connect to a CSP.";
 }
 feature multicast {
  description
  "Enables multicast capabilities in a VPN.";
 }
 feature ipv4 {
  description
  "Enables IPv4 support in a VPN.";
 }
 feature ipv6 {
  description
  "Enables IPv6 support in a VPN.";
 }
 feature lan-tag {
  description
  "Enables LAN Tag support in a VPN Policy filter.";
 }
 feature carrierscarrier {
  description



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  "Enables support of CsC.";
 }
 feature extranet-vpn {
  description
  "Enables support of extranet VPNs.";
 }
 feature site-diversity {
  description
  "Enables support of site diversity constraints.";
 }
 feature encryption {
  description
  "Enables support of encryption.";
 }
 feature qos {
  description
  "Enables support of classes of services.";
 }
 feature qos-custom {
  description
  "Enables support of the custom QoS profile.";
 }
 feature rtg-bgp {
  description
  "Enables support of the BGP routing protocol.";
 }
 feature rtg-rip {
  description
  "Enables support of the RIP routing protocol.";
 }
 feature rtg-ospf {
  description
  "Enables support of the OSPF routing protocol.";
 }
 feature rtg-ospf-sham-link {
  description
  "Enables support of OSPF sham links.";
 }
 feature rtg-vrrp {
  description
  "Enables support of the VRRP routing protocol.";
 }
 feature fast-reroute {
  description
  "Enables support of Fast Reroute.";
 }
 feature bfd {
  description



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  "Enables support of BFD.";
 }
 feature always-on {
  description
  "Enables support of the 'always-on' access constraint.";
 }
 feature requested-type {
  description
  "Enables support of the 'requested-type' access constraint.";
 }
 feature bearer-reference {
  description
  "Enables support of the 'bearer-reference' access constraint.";
 }
 feature target-sites {
  description
  "Enables support of the 'target-sites' match flow parameter.";
 }
 /* Typedefs */
 typedef svc-id {
  type string;
  description
  "Defines a type of service component identifier.";
 }
 typedef template-id {
  type string;
  description
  "Defines a type of service template identifier.";
 }
 typedef address-family {
  type enumeration {
   enum ipv4 {
    description
    "IPv4 address family.";
   }
   enum ipv6 {
    description
    "IPv6 address family.";
   }
  }
  description
  "Defines a type for the address family.";
 }
 /* Identities */
 identity site-network-access-type {
  description
  "Base identity for site-network-access type.";
 }



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 identity point-to-point {
  base site-network-access-type;
  description
  "Identity for point-to-point connection.";
 }
 identity multipoint {
  base site-network-access-type;
  description
  "Identity for multipoint connection.
  Example: Ethernet broadcast segment.";
 }
 identity placement-diversity {
  description
  "Base identity for site placement constraints.";
 }
 identity bearer-diverse {
  base placement-diversity;
  description
  "Identity for bearer diversity.
  The bearers should not use common elements.";
 }
 identity pe-diverse {
  base placement-diversity;
  description
  "Identity for PE diversity.";
 }
 identity pop-diverse {
  base placement-diversity;
  description
  "Identity for POP diversity.";
 }
 identity linecard-diverse {
  base placement-diversity;
  description
  "Identity for linecard diversity.";
 }
 identity same-pe {
  base placement-diversity;
  description
  "Identity for having sites connected on the same PE.";
 }
 identity same-bearer {
  base placement-diversity;
  description
  "Identity for having sites connected using the same bearer.";
 }
 identity customer-application {
  description



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  "Base identity for customer application.";
 }
 identity web {
  base customer-application;
  description
  "Identity for Web application (e.g., HTTP, HTTPS).";
 }
 identity mail {
  base customer-application;
  description
  "Identity for mail application.";
 }
 identity file-transfer {
  base customer-application;
  description
  "Identity for file transfer application (e.g., FTP, SFTP).";
 }
 identity database {
  base customer-application;
  description
  "Identity for database application.";
 }
 identity social {
  base customer-application;
  description
  "Identity for social-network application.";
 }
 identity games {
  base customer-application;
  description
  "Identity for gaming application.";
 }
 identity p2p {
  base customer-application;
  description
  "Identity for peer-to-peer application.";
 }
 identity network-management {
  base customer-application;
  description
  "Identity for management application
  (e.g., Telnet, syslog, SNMP).";
 }
 identity voice {
  base customer-application;
  description
  "Identity for voice application.";
 }



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 identity video {
  base customer-application;
  description
  "Identity for video conference application.";
 }
 identity embb {
  base customer-application;
  description
  "Identity for an enhanced Mobile Broadband (eMBB)
  application.  Note that an eMBB application demands
  network performance with a wide variety of
  characteristics, such as data rate, latency,
  loss rate, reliability, and many other parameters.";
}
identity urllc {
  base customer-application;
  description
  "Identity for an Ultra-Reliable and Low Latency
  Communications (URLLC) application.  Note that a
  URLLC application demands network performance
  with a wide variety of characteristics, such as latency,
  reliability, and many other parameters.";
 }
 identity mmtc {
   base customer-application;
   description
   "Identity for a massive Machine Type
   Communications (mMTC) application.  Note that an
   mMTC application demands network performance
   with a wide variety of characteristics, such as data
   rate, latency, loss rate, reliability, and many
   other parameters.";
 }
 identity site-vpn-flavor {
  description
  "Base identity for the site VPN service flavor.";
 }
 identity site-vpn-flavor-single {
  base site-vpn-flavor;
  description
  "Base identity for the site VPN service flavor.
  Used when the site belongs to only one VPN.";
 }
 identity site-vpn-flavor-multi {
  base site-vpn-flavor;
  description
  "Base identity for the site VPN service flavor.
  Used when a logical connection of a site



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  belongs to multiple VPNs.";
 }
 identity site-vpn-flavor-sub {
  base site-vpn-flavor;
  description
  "Base identity for the site VPN service flavor.
  Used when a site has multiple logical connections.
  Each connection may belong to different multiple VPNs.";
 }
 identity site-vpn-flavor-nni {
  base site-vpn-flavor;
  description
  "Base identity for the site VPN service flavor.
  Used to describe an NNI option A connection.";
 }
 identity management {
  description
  "Base identity for site management scheme.";
 }
 identity co-managed {
  base management;
  description
  "Base identity for co-managed site.";
 }
 identity customer-managed {
  base management;
  description
  "Base identity for customer-managed site.";
 }
 identity provider-managed {
  base management;
  description
  "Base identity for provider-managed site.";
 }
 identity address-allocation-type {
  description
  "Base identity for address-allocation-type for PE-CE link.";
 }
 identity provider-dhcp {
  base address-allocation-type;
  description
  "Provider network provides DHCP service to customer.";
 }
 identity provider-dhcp-relay {
  base address-allocation-type;
  description
  "Provider network provides DHCP relay service to customer.";
 }



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 identity provider-dhcp-slaac {
  base address-allocation-type;
  description
  "Provider network provides DHCP service to customer,
  as well as SLAAC.";
 }
 identity static-address {
  base address-allocation-type;
  description
  "Provider-to-customer addressing is static.";
 }
 identity slaac {
  base address-allocation-type;
  description
  "Use IPv6 SLAAC.";
 }
 identity site-role {
  description
  "Base identity for site type.";
 }
 identity any-to-any-role {
  base site-role;
  description
  "Site in an any-to-any IP VPN.";
 }
 identity spoke-role {
  base site-role;
  description
  "Spoke site in a Hub-and-Spoke IP VPN.";
 }
 identity hub-role {
  base site-role;
  description
  "Hub site in a Hub-and-Spoke IP VPN.";
 }
 identity vpn-topology {
  description
  "Base identity for VPN topology.";
 }
 identity any-to-any {
  base vpn-topology;
  description
  "Identity for any-to-any VPN topology.";
 }
 identity hub-spoke {
  base vpn-topology;
  description
  "Identity for Hub-and-Spoke VPN topology.";



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 }
 identity hub-spoke-disjoint {
  base vpn-topology;
  description
  "Identity for Hub-and-Spoke VPN topology
  where Hubs cannot communicate with each other.";
 }
 identity multicast-tree-type {
  description
  "Base identity for multicast tree type.";
 }
 identity ssm-tree-type {
  base multicast-tree-type;
  description
  "Identity for SSM tree type.";
 }
 identity asm-tree-type {
  base multicast-tree-type;
  description
  "Identity for ASM tree type.";
 }
 identity bidir-tree-type {
  base multicast-tree-type;
  description
  "Identity for bidirectional tree type.";
 }
 identity multicast-rp-discovery-type {
  description
  "Base identity for RP discovery type.";
 }
 identity auto-rp {
  base multicast-rp-discovery-type;
  description
  "Base identity for Auto-RP discovery type.";
 }
 identity static-rp {
  base multicast-rp-discovery-type;
  description
  "Base identity for static type.";
 }
 identity bsr-rp {
  base multicast-rp-discovery-type;
  description
  "Base identity for BSR discovery type.";
 }
 identity routing-protocol-type {
  description
  "Base identity for routing protocol type.";



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 }
 identity ospf {
  base routing-protocol-type;
  description
  "Identity for OSPF protocol type.";
 }
 identity bgp {
  base routing-protocol-type;
  description
  "Identity for BGP protocol type.";
 }
 identity static {
  base routing-protocol-type;
  description
  "Identity for static routing protocol type.";
 }
 identity rip {
  base routing-protocol-type;
  description
  "Identity for RIP protocol type.";
 }
 identity vrrp {
  base routing-protocol-type;
  description
  "Identity for VRRP protocol type.
  This is to be used when LANs are directly connected
  to PE routers.";
 }
 identity direct {
  base routing-protocol-type;
  description
  "Identity for direct protocol type.";
 }
 identity protocol-type {
  description
  "Base identity for protocol field type.";
 }
 identity tcp {
  base protocol-type;
  description
  "TCP protocol type.";
 }
 identity udp {
  base protocol-type;
  description
  "UDP protocol type.";
 }




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 identity icmp {
  base protocol-type;
  description
  "ICMP protocol type.";
 }
 identity icmp6 {
  base protocol-type;
  description
  "ICMPv6 protocol type.";
 }
 identity gre {
  base protocol-type;
  description
  "GRE protocol type.";
 }
 identity ipip {
  base protocol-type;
  description
  "IP-in-IP protocol type.";
 }
 identity hop-by-hop {
  base protocol-type;
  description
  "Hop-by-Hop IPv6 header type.";
 }
 identity routing {
  base protocol-type;
  description
  "Routing IPv6 header type.";
 }
 identity esp {
  base protocol-type;
  description
  "ESP header type.";
 }
 identity ah {
  base protocol-type;
  description
  "AH header type.";
 }
 identity vpn-policy-filter-type {
  description
  "Base identity for VPN Policy filter type.";
 }
 identity ipv4 {
   base vpn-policy-filter-type;
   description
   "Identity for IPv4 Prefix filter type.";



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 }
 identity ipv6 {
   base vpn-policy-filter-type;
   description
   "Identity for IPv6 Prefix filter type.";
}
 identity lan {
   base vpn-policy-filter-type;
   description
   "Identity for LAN Tag filter type.";
}

 identity qos-profile-direction {
  description
  "Base identity for QoS profile direction.";
 }

 identity site-to-wan {
   base qos-profile-direction;
   description
   "Identity for Site-to-WAN direction.";
 }
 identity wan-to-site {
   base qos-profile-direction;
   description
   "Identity for WAN-to-Site direction.";
 }
 identity both {
   base qos-profile-direction;
   description
   "Identity for both WAN-to-Site direction
   and Site-to-WAN direction.";
 }
 /* Groupings */
 grouping vpn-service-cloud-access {
  container cloud-accesses {
   if-feature cloud-access;
   list cloud-access {
    key cloud-identifier;
    leaf cloud-identifier {
     type leafref {
      path "/l3vpn-svc/vpn-profiles/"+
      "valid-provider-identifiers/cloud-identifier/id";
     }
     description
     "Identification of cloud service.
     Local administration meaning.";
    }



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    choice list-flavor {
     case permit-any {
      leaf permit-any {
       type empty;
       description
       "Allows all sites.";
      }
     }
     case deny-any-except {
      leaf-list permit-site {
       type leafref {
        path "/l3vpn-svc/sites/site/site-id";
       }
       description
       "Site ID to be authorized.";
      }
     }
     case permit-any-except {
      leaf-list deny-site {
       type leafref {
       path "/l3vpn-svc/sites/site/site-id";
      }
      description
      "Site ID to be denied.";
      }
     }
     description
     "Choice for cloud access policy.  By
     default, all sites in the IP VPN MUST
     be authorized to access the cloud.";
    }
    container address-translation {
     container nat44 {
      leaf enabled {
       type boolean;
        default false;
        description
        "Controls whether or not Network address
        translation from IPv4 to IPv4 (NAT44)
        [RFC3022] is required.";
      }
      leaf nat44-customer-address {
       type inet:ipv4-address;
        description
        "Address to be used for network address
        translation from IPv4 to IPv4.  This is
        to be used if the customer is providing
        the IPv4 address.  If the customer address



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        is not set, the model assumes that the
        provider will allocate the address.";
      }
      description
      "IPv4-to-IPv4 translation.";
     }
     description
     "Container for NAT.";
    }
    description
    "Cloud access configuration.";
   }
   description
   "Container for cloud access configurations.";
  }
  description
  "Grouping for VPN cloud definition.";
 }
 grouping multicast-rp-group-cfg {
  choice group-format {
   mandatory true;
   case singleaddress {
    leaf group-address {
     type inet:ip-address;
     description
     "A single multicast group address.";
    }
   }
   case startend {
    leaf group-start {
     type inet:ip-address;
     description
     "The first multicast group address in
     the multicast group address range.";
    }
    leaf group-end {
     type inet:ip-address;
     description
     "The last multicast group address in
     the multicast group address range.";
    }
   }
   description
   "Choice for multicast group format.";
  }
  description
  "This grouping defines multicast group or
  multicast groups for RP-to-group mapping.";



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 }
 grouping vpn-service-multicast {
  container multicast {
   if-feature multicast;
   leaf enabled {
    type boolean;
    default false;
    description
    "Enables multicast.";
   }
   container customer-tree-flavors {
    leaf-list tree-flavor {
     type identityref {
      base multicast-tree-type;
     }
     description
      "Type of tree to be used.";
    }
    description
    "Type of trees used by customer.";
   }
   container rp {
    container rp-group-mappings {
     list rp-group-mapping {
      key id;
      leaf id {
       type uint16;
       description
       "Unique identifier for the mapping.";
      }
      container provider-managed {
       leaf enabled {
        type boolean;
        default false;
        description
        "Set to true if the Rendezvous Point (RP)
        must be a provider-managed node.  Set to false
        if it is a customer-managed node.";
       }
       leaf rp-redundancy {
        type boolean;
        default false;
        description
        "If true, a redundancy mechanism for the RP
        is required.";
       }
       leaf optimal-traffic-delivery {
        type boolean;



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        default false;
        description
        "If true, the SP must ensure that
        traffic uses an optimal path.  An SP may use
        Anycast RP or RP-tree-to-SPT switchover
        architectures.";
       }
       description
       "Parameters for a provider-managed RP.";
      }
      leaf rp-address {
       when "../provider-managed/enabled = 'false'" {
        description
        "Relevant when the RP is not provider-managed.";
       }
       type inet:ip-address;
         mandatory true;
       description
       "Defines the address of the RP.
       Used if the RP is customer-managed.";
      }
      container groups {
       list group {
        key id;
        leaf id {
         type uint16;
         description
         "Identifier for the group.";
        }
        uses multicast-rp-group-cfg;
        description
        "List of multicast groups.";
       }
       description
       "Multicast groups associated with the RP.";
      }
      description
      "List of RP-to-group mappings.";
     }
     description
     "RP-to-group mappings parameters.";
    }
    container rp-discovery {
     leaf rp-discovery-type {
      type identityref {
       base multicast-rp-discovery-type;
       }
      default static-rp;



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      description
      "Type of RP discovery used.";
     }
     container bsr-candidates {
       when "derived-from-or-self(../rp-discovery-type, "+
           "'l3vpn-svc:bsr-rp')" {
       description
       "Only applicable if discovery type
       is BSR-RP.";
      }
      leaf-list bsr-candidate-address {
       type inet:ip-address;
        description
        "Address of BSR candidate.";
      }
      description
      "Container for List of Customer
      BSR candidate's addresses.";
     }
     description
     "RP discovery parameters.";
    }
    description
    "RP parameters.";
   }
   description
   "Multicast global parameters for the VPN service.";
  }
  description
  "Grouping for multicast VPN definition.";
 }
 grouping vpn-service-mpls {
  leaf carrierscarrier {
   if-feature carrierscarrier;
    type boolean;
    default false;
    description
    "The VPN is using CsC, and so MPLS is required.";
  }
  description
  "Grouping for MPLS CsC definition.";
 }
 grouping customer-location-info {
  container locations {
   list location {
    key location-id;
    leaf location-id {
     type svc-id;



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     description
     "Identifier for a particular location.";
    }
    leaf address {
     type string;
     description
     "Address (number and street) of the site.";
    }
    leaf postal-code {
     type string;
     description
     "Postal code of the site.";
    }
    leaf state {
     type string;
     description
     "State of the site.  This leaf can also be
     used to describe a region for a country that
     does not have states.";
    }
    leaf city {
     type string;
     description
     "City of the site.";
    }
    leaf country-code {
     type string {
      pattern '[A-Z]{2}';
     }
     description
     "Country of the site.
     Expressed as ISO ALPHA-2 code.";
    }
    description
    "Location of the site.";
   }
   description
   "List of locations for the site.";
  }
  description
  "This grouping defines customer location parameters.";
 }
 grouping site-group {
  container groups {
   list group {
    key group-id;
    leaf group-id {
     type string;



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     description
     "Group-id the site belongs to.";
    }
    description
    "List of group-ids.";
   }
   description
   "Groups the site or site-network-access belongs to.";
  }
  description
  "Grouping definition to assign
  group-ids to site or site-network-access.";
 }
 grouping site-diversity {
  container site-diversity {
   if-feature site-diversity;
   uses site-group;
   description
   "Diversity constraint type.  All
   site-network-accesses will inherit
   the group values defined here.";
  }
  description
  "This grouping defines site
  diversity parameters.";
 }
 grouping access-diversity {
  container access-diversity {
   if-feature site-diversity;
   uses site-group;
   container constraints {
    list constraint {
     key constraint-type;
     leaf constraint-type {
      type identityref {
       base placement-diversity;
      }
      description
      "Diversity constraint type.";
     }
     container target {
      choice target-flavor {
       default id;
       case id {
        list group {
         key group-id;
         leaf group-id {
          type string;



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          description
          "The constraint will be applied against
          this particular group-id for this site
          network access level.";
         }
         description
         "List of group-ids associated with one specific
         constraint for this site network access level.";
        }
       }
       case all-accesses {
        leaf all-other-accesses {
         type empty;
         description
         "The constraint will be applied against
         all other site network accesses of this site.";
        }
       }
       case all-groups {
        leaf all-other-groups {
         type empty;
         description
         "The constraint will be applied against
         all other groups managed by the customer.";
        }
       }
       description
       "Choice for the target flavor definition.";
      }
      description
      "The constraint will be applied against a
      Specific target, and the target can be a list
      of group-ids,all other site network accesses of
      this site, or all other groups managed by the
      customer.";
     }
     description
     "List of constraints.";
    }
    description
    "Placement constraints for this site network access.";
   }
   description
   "Diversity parameters.";
  }
  description
  "This grouping defines access diversity parameters.";
 }



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 grouping operational-requirements {
   leaf requested-site-start {
    type yang:date-and-time;
     description
     "Optional leaf indicating requested date and
     time when the service at a particular site is
     expected to start.";
  }

  leaf requested-site-stop {
    type yang:date-and-time;
     description
     "Optional leaf indicating requested date and
     time when the service at a particular site is
     expected to stop.";
  }
  description
  "This grouping defines some operational
  parameters.";
 }
 grouping operational-requirements-ops {
   leaf actual-site-start {
    type yang:date-and-time;
    config false;
     description
     "Optional leaf indicating actual date and
     time when the service at a particular site
     actually started.";
  }
  leaf actual-site-stop {
   type yang:date-and-time;
   config false;
     description
     "Optional leaf indicating actual date and
     time when the service at a particular site
     actually stopped.";
  }
  description
  "This grouping defines some operational
  parameters.";
 }
 grouping flow-definition {
  container match-flow {
   leaf dscp {
    type inet:dscp;
     description
     "DSCP value.";
   }



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   leaf dot1p {
    type uint8 {
     range "0..7";
    }
    description
    "802.1p matching.";
   }
   leaf ipv4-src-prefix {
    type inet:ipv4-prefix;
     description
     "Match on IPv4 src address.";
   }
   leaf ipv6-src-prefix {
    type inet:ipv6-prefix;
     description
     "Match on IPv6 src address.";
   }
   leaf ipv4-dst-prefix {
    type inet:ipv4-prefix;
     description
     "Match on IPv4 dst address.";
   }
   leaf ipv6-dst-prefix {
    type inet:ipv6-prefix;
    description
    "Match on IPv6 dst address.";
   }
   leaf l4-src-port {
    type inet:port-number;
        must "current() < ../l4-src-port-range/lower-port or "+
        "current() > ../l4-src-port-range/upper-port" {
     description
     "If l4-src-port and l4-src-port-range/lower-port and
     upper-port are set at the same time, l4-src-port
     should not overlap with l4-src-port-range.";
     }
     description
     "Match on Layer 4 src port.";
   }
   leaf-list target-sites {
     if-feature target-sites;
     type svc-id;
     description
     "Identify a site as traffic destination.";
   }
   container l4-src-port-range {
     leaf lower-port {
     type inet:port-number;



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     description
     "Lower boundary for port.";
    }
    leaf upper-port {
     type inet:port-number;
     must ". >= ../lower-port" {
      description
      "Upper boundary for port.  If it
      exists, the upper boundary must be
      higher than the lower boundary.";
     }
     description
     "Upper boundary for port.";
    }
     description
     "Match on Layer 4 src port range.  When
     only the lower-port is present, it represents
     a single port.  When both the lower-port and
     upper-port are specified, it implies
     a range inclusive of both values.";
   }
   leaf l4-dst-port {
    type inet:port-number;
         must "current() < ../l4-dst-port-range/lower-port or "+
         "current() > ../l4-dst-port-range/upper-port" {
     description
     "If l4-dst-port and l4-dst-port-range/lower-port
     and upper-port are set at the same time,
     l4-dst-port should not overlap with
     l4-src-port-range.";
     }
     description
     "Match on Layer 4 dst port.";
   }
   container l4-dst-port-range {
    leaf lower-port {
     type inet:port-number;
     description
     "Lower boundary for port.";
    }
    leaf upper-port {
     type inet:port-number;
     must ". >= ../lower-port" {
     description
     "Upper boundary must be
     higher than lower boundary.";
     }
     description



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     "Upper boundary for port.  If it exists,
     upper boundary must be higher than lower
     boundary.";
    }
    description
    "Match on Layer 4 dst port range.  When only
    lower-port is present, it represents a single
    port.  When both lower-port and upper-port are
    specified, it implies a range inclusive of both
    values.";
   }
   leaf protocol-field {
    type union {
     type uint8;
     type identityref {
      base protocol-type;
     }
    }
    description
    "Match on IPv4 protocol or IPv6 Next Header field.";
   }
   description
   "Describes flow-matching criteria.";
  }
  description
  "Flow definition based on criteria.";
 }
 grouping site-service-basic {
  leaf svc-input-bandwidth {
    type uint64;
    units bps;
    mandatory true;
     description
     "From the customer site's perspective, the service
     input bandwidth of the connection or download
     bandwidth from the SP to the site.";
  }
  leaf svc-output-bandwidth {
   type uint64;
   units bps;
   mandatory true;
     description
     "From the customer site's perspective, the service
     output bandwidth of the connection or upload
     bandwidth from the site to the SP.";
  }
  leaf svc-mtu {
   type uint16;



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   units bytes;
   mandatory true;
    description
    "MTU at service level.  If the service is IP,
    it refers to the IP MTU.  If CsC is enabled,
    the requested 'svc-mtu' leaf will refer to the
    MPLS MTU and not to the IP MTU.";
  }
  description
  "Defines basic service parameters for a site.";
 }
 grouping site-protection {
  container traffic-protection {
   if-feature fast-reroute;
   leaf enabled {
    type boolean;
    default false;
     description
     "Enables traffic protection of access link.";
   }
   description
   "Fast Reroute service parameters for the site.";
  }
  description
  "Defines protection service parameters for a site.";
 }
 grouping site-service-mpls {
  container carrierscarrier {
   if-feature carrierscarrier;
   leaf signalling-type {
    type enumeration {
    enum ldp {
     description
     "Use LDP as the signalling protocol
     between the PE and the CE.  In this case,
     an IGP routing protocol must also be activated.";
     }
    enum bgp {
     description
     "Use BGP (as per RFC 8277) as the signalling protocol
     between the PE and the CE.
     In this case, BGP must also be configured as
     the routing protocol.";
     }
    }
    default bgp;
    description
    "MPLS signalling type.";



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   }
     description
     "This container is used when the customer provides
     MPLS-based services.  This is only used in the case
     of CsC (i.e., a customer builds an MPLS service using
     an IP VPN to carry its traffic).";
  }
     description
     "Defines MPLS service parameters for a site.";
 }
 grouping site-service-qos-profile {
  container qos {
   if-feature qos;
   container qos-classification-policy {
    list rule {
     key id;
     ordered-by user;
     leaf id {
      type string;
      description
      "A description identifying the
       qos-classification-policy rule.";
     }
     choice match-type {
      default match-flow;
      case match-flow {
      uses flow-definition;
      }
      case match-application {
       leaf match-application {
        type identityref {
         base customer-application;
        }
         description
         "Defines the application to match.";
       }
      }
      description
      "Choice for classification.";
     }
     leaf target-class-id {
      type string;
      description
      "Identification of the class of service.
      This identifier is internal to the administration.";
     }
     description
     "List of marking rules.";



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    }
    description
    "Configuration of the traffic classification policy.";
   }
   container qos-profile {
    choice qos-profile {
     description
     "Choice for QoS profile.
     Can be standard profile or customized profile.";
     case standard {
      description
      "Standard QoS profile.";
      leaf profile {
       type leafref {
       path "/l3vpn-svc/vpn-profiles/valid-provider-identifiers"+
           "/qos-profile-identifier/id";
       }
       description
       "QoS profile to be used.";
      }
     }
     case custom {
      description
      "Customized QoS profile.";
       container classes {
        if-feature qos-custom;
        list class {
         key class-id;
         leaf class-id {
         type string;
                  description
                  "Identification of the class of service.
                  This identifier is internal to the
                  administration.";
         }
         leaf direction {
                  type identityref {
                   base qos-profile-direction;
                   }
                  default both;
                   description
                   "The direction to which the QoS profile
                   is applied.";
                }
                 leaf rate-limit {
                  type decimal64 {
                   fraction-digits 5;
                   range "0..100";



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          }
                  units percent;
                   description
                   "To be used if the class must be rate-limited.
                   Expressed as percentage of the service
                   bandwidth.";
        }
        container latency {
         choice flavor {
          case lowest {
           leaf use-lowest-latency {
            type empty;
             description
             "The traffic class should use the path with the
             lowest latency.";
           }
          }
          case boundary {
           leaf latency-boundary {
            type uint16;
            units msec;
            default 400;
             description
             "The traffic class should use a path with a
             defined maximum latency.";
           }
          }
          description
          "Latency constraint on the traffic class.";
         }
         description
         "Latency constraint on the traffic class.";
        }
        container jitter {
         choice flavor {
          case lowest {
           leaf use-lowest-jitter {
            type empty;
             description
             "The traffic class should use the path with the
             lowest jitter.";
           }
          }
          case boundary {
           leaf latency-boundary {
            type uint32;
            units usec;
            default 40000;



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             description
             "The traffic class should use a path with a
             defined maximum jitter.";
           }
          }
          description
          "Jitter constraint on the traffic class.";
         }
         description
         "Jitter constraint on the traffic class.";
        }
        container bandwidth {
         leaf guaranteed-bw-percent {
          type decimal64 {
                  fraction-digits 5;
                  range "0..100";
          }
          units percent;
          mandatory true;
           description
           "To be used to define the guaranteed bandwidth
           as a percentage of the available service bandwidth.";
         }
         leaf end-to-end {
          type empty;
           description
           "Used if the bandwidth reservation
           must be done on the MPLS network too.";
         }
         description
         "Bandwidth constraint on the traffic class.";
        }
        description
        "List of classes of services.";
       }
       description
       "Container for list of classes of services.";
      }
     }
    }
    description
    "QoS profile configuration.";
   }
   description
   "QoS configuration.";
  }
  description
  "This grouping defines QoS parameters for a site.";



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 }
 grouping site-security-authentication {
  container authentication {
     description
     "Authentication parameters.";
  }
  description
  "This grouping defines authentication parameters for a site.";
 }
 grouping site-security-encryption {
  container encryption {
   if-feature encryption;
   leaf enabled {
    type boolean;
    default false;
     description
     "If true, traffic encryption on the connection is required.";
   }
   leaf layer {
      when "../enabled = 'true'" {
         description
         "Require a value for layer when enabled is true.";
       }
    type enumeration {
     enum layer2 {
      description
      "Encryption will occur at Layer 2.";
     }
     enum layer3 {
      description
      "Encryption will occur at Layer 3.
      For example, IPsec may be used when
      a customer requests Layer 3 encryption.";
     }
    }
    description
     "Layer on which encryption is applied.";
   }
   container encryption-profile {
    choice profile {
     case provider-profile {
      leaf profile-name {
       type leafref {
        path "/l3vpn-svc/vpn-profiles/valid-provider-identifiers"+
                "/encryption-profile-identifier/id";
       }
         description
         "Name of the SP profile to be applied.";



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      }
     }
     case customer-profile {
      leaf algorithm {
       type string;
         description
         "Encryption algorithm to be used.";
      }
      choice key-type {
       default psk;
       case psk {
        leaf preshared-key {
         type string;
         description
         "Pre-Shared Key (PSK) coming from the customer.";
        }
       }
       description
       "Type of keys to be used.";
      }
     }
     description
     "Choice of encryption profile.  The encryption
     profile can be the provider profile or customer profile.";
    }
    description
    "Profile of encryption to be applied.";
   }
   description
   "Encryption parameters.";
  }
  description
  "This grouping defines encryption parameters for a site.";
 }
 grouping site-attachment-bearer {
  container bearer {
   container requested-type {
    if-feature requested-type;
    leaf requested-type {
     type string;
     description
     "Type of requested bearer: Ethernet, DSL,
     Wireless, etc. Operator specific.";
    }
    leaf strict {
     type boolean;
     default false;
     description



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     "Defines whether requested-type is a preference
     or a strict requirement.";
    }
     description
     "Container for requested-type.";
   }
   leaf always-on {
    if-feature always-on;
    type boolean;
    default true;
     description
     "Request for an always-on access type.
     For example, this could mean no dial access type.";
   }
   leaf bearer-reference {
    if-feature bearer-reference;
    type string;
     description
     "This is an internal reference for the SP.";
   }
     description
     "Bearer-specific parameters.
     To be augmented.";
  }
  description
  "Defines physical properties of a site attachment.";
 }
 grouping site-routing {
  container routing-protocols {
   list routing-protocol {
    key type;
    leaf type {
     type identityref {
      base routing-protocol-type;
     }
     description
     "Type of routing protocol.";
    }
    container ospf {
     when "derived-from-or-self(../type, 'l3vpn-svc:ospf')" {
     description
     "Only applies when protocol is OSPF.";
     }
     if-feature rtg-ospf;
     leaf-list address-family {
      type address-family;
          min-elements "1";
         description



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         "If OSPF is used on this site, this node
         contains a configured value.  This node
         contains at least one address family
         to be activated.";
     }
     leaf area-address {
      type yang:dotted-quad;
      mandatory true;
         description
         "Area address.";
     }
     leaf metric {
      type uint16;
      default 1;
         description
         "Metric of the PE-CE link.  It is used
         in the routing state calculation and
         path selection.";
     }
     container sham-links {
      if-feature rtg-ospf-sham-link;
      list sham-link {
       key target-site;
       leaf target-site {
        type svc-id;
         description
         "Target site for the sham link connection.
         The site is referred to by its ID.";
       }
       leaf metric {
        type uint16;
        default 1;
         description
         "Metric of the sham link.  It is used in
         the routing state calculation and path
         selection.  The default value is set
         to 1.";
       }
         description
         "Creates a sham link with another site.";
      }
      description
      "List of sham links.";
     }
     description
     "OSPF-specific configuration.";
    }
    container bgp {



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     when "derived-from-or-self(../type, 'l3vpn-svc:bgp')" {
      description
      "Only applies when protocol is BGP.";
     }
     if-feature rtg-bgp;
     leaf autonomous-system {
      type uint32;
      mandatory true;
         description
         "Customer AS number in case the customer
         requests BGP routing.";
     }
     leaf-list address-family {
      type address-family;
          min-elements "1";
         description
         "If BGP is used on this site, this node
         contains a configured value.  This node
         contains at least one address family
         to be activated.";
     }
     description
     "BGP-specific configuration.";
    }
    container static {
     when "derived-from-or-self(../type, 'l3vpn-svc:static')" {
       description
       "Only applies when protocol is static.
       BGP activation requires the SP to know
       the address of the customer peer.  When
       BGP is enabled, the 'static-address'
       allocation type for the IP connection
       MUST be used.";
     }
     container cascaded-lan-prefixes {
      list ipv4-lan-prefixes {
       if-feature ipv4;
       key "lan next-hop";
       leaf lan {
        type inet:ipv4-prefix;
        description
        "LAN prefixes.";
       }
       leaf lan-tag {
        type string;
         description
         "Internal tag to be used in VPN policies.";
       }



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       leaf next-hop {
        type inet:ipv4-address;
         description
         "Next-hop address to use on the customer side.";
       }
       description
       "List of LAN prefixes for the site.";
      }
      list ipv6-lan-prefixes {
       if-feature ipv6;
       key "lan next-hop";
       leaf lan {
        type inet:ipv6-prefix;
         description
         "LAN prefixes.";
       }
       leaf lan-tag {
        type string;
        description
        "Internal tag to be used in VPN policies.";
       }
       leaf next-hop {
        type inet:ipv6-address;
         description
         "Next-hop address to use on the customer side.";
       }
       description
       "List of LAN prefixes for the site.";
      }
      description
      "LAN prefixes from the customer.";
     }
     description
     "Configuration specific to static routing.";
    }
    container rip {
     when "derived-from-or-self(../type, 'l3vpn-svc:rip')" {
      description
      "Only applies when the protocol is RIP.  For IPv4,
      the model assumes that RIP version 2 is used.";
     }
     if-feature rtg-rip;
     leaf-list address-family {
      type address-family;
          min-elements "1";
         description
         "If RIP is used on this site, this node
         contains a configured value.  This node



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         contains at least one address family
         to be activated.";
     }
     description
     "Configuration specific to RIP routing.";
    }
    container vrrp {
     when "derived-from-or-self(../type, 'l3vpn-svc:vrrp')" {
      description
      "Only applies when protocol is VRRP.";
     }
     if-feature rtg-vrrp;
     leaf-list address-family {
      type address-family;
          min-elements "1";
         description
         "If VRRP is used on this site, this node
         contains a configured value.  This node contains
         at least one address family to be activated.";
     }
     description
     "Configuration specific to VRRP routing.";
    }
    description
    "List of routing protocols used on
    the site.  This list can be augmented.";
   }
   description
   "Defines routing protocols.";
  }
  description
  "Grouping for routing protocols.";
 }
 grouping site-attachment-ip-connection {
   container ip-connection {
     container ipv4 {
     if-feature ipv4;
      leaf address-allocation-type {
      type identityref {
       base address-allocation-type;
     }
     must "not(derived-from-or-self(current(), 'l3vpn-svc:slaac') or "+
         "derived-from-or-self(current(), "+
         "'l3vpn-svc:provider-dhcp-slaac'))" {
     error-message "SLAAC is only applicable to IPv6";
     }
     description
     "Defines how addresses are allocated.



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     If there is no value for the address
     allocation type, then IPv4 is not enabled.";
    }
   container provider-dhcp {
     when "derived-from-or-self(../address-allocation-type, "+
     "'l3vpn-svc:provider-dhcp')" {
     description
     "Only applies when addresses are allocated by DHCP.";
   }
     leaf provider-address {
      type inet:ipv4-address;
         description
         "Address of provider side.  If provider-address is not
         specified, then prefix length should not be specified
         either.  It also implies provider-dhcp allocation is
         not enabled.  If provider-address is specified, then
         the prefix length may or may not be specified.";
     }
     leaf prefix-length {
      type uint8 {
      range "0..32";
      }
         must "(../provider-address)" {
          error-message
          "If the prefix length is specified, provider-address
          must also be specified.";
             description
             "If the prefix length is specified, provider-address
             must also be specified.";
        }
     description
     "Subnet prefix length expressed in bits.
     If not specified, or specified as zero,
     this means the customer leaves the actual
     prefix length value to the provider.";
     }
     choice address-assign {
      default number;
      case number {
       leaf number-of-dynamic-address {
        type uint16;
        default 1;
         description
         "Describes the number of IP addresses
         the customer requires.";
       }
      }
      case explicit {



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       container customer-addresses {
        list address-group {
         key "group-id";
         leaf group-id {
         type string;
         description
         "Group-id for the address range from
         start-address to end-address.";
         }
        leaf start-address {
         type inet:ipv4-address;
          description
          "First address.";
         }
        leaf end-address {
         type inet:ipv4-address;
         description
         "Last address.";
         }
         description
         "Describes IP addresses allocated by DHCP.
         When only start-address or only end-address
         is present, it represents a single address.
         When both start-address and end-address are
         specified, it implies a range inclusive of both
         addresses.  If no address is specified, it implies
         customer addresses group is not supported.";
        }
         description
         "Container for customer addresses is allocated by DHCP.";
       }
     }
         description
         "Choice for the way to assign addresses.";
     }
         description
         "DHCP allocated addresses related parameters.";
    }
 container dhcp-relay {
   when "derived-from-or-self(../address-allocation-type, "+
   "'l3vpn-svc:provider-dhcp-relay')" {
     description
     "Only applies when provider is required to implement
     DHCP relay function.";
  }
 leaf provider-address {
  type inet:ipv4-address;
     description



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     "Address of provider side.  If provider-address is not
     specified, then prefix length should not be specified
     either.  It also implies provider-dhcp allocation is
     not enabled.  If provider-address is specified, then
     prefix length may or may not be specified.";
 }
 leaf prefix-length {
  type uint8 {
  range "0..32";
  }
 must "(../provider-address)" {
  error-message
     "If prefix length is specified, provider-address
      must also be specified.";
     description
     "If prefix length is specified, provider-address
     must also be specified.";
}
     description
     "Subnet prefix length expressed in bits.  If not
     specified, or specified as zero, this means the
     customer leaves the actual prefix length value
     to the provider.";
 }
 container customer-dhcp-servers {
  leaf-list server-ip-address {
  type inet:ipv4-address;
     description
     "IP address of customer DHCP server.";
 }
 description
 "Container for list of customer DHCP servers.";
 }
 description
 "DHCP relay provided by operator.";
}
 container addresses {
   when "derived-from-or-self(../address-allocation-type, "+
   "'l3vpn-svc:static-address')" {
   description
   "Only applies when protocol allocation type is static.";
    }
     leaf provider-address {
      type inet:ipv4-address;
         description
         "IPv4 Address List of the provider side.
         When the protocol allocation type is static,
         the provider address must be configured.";



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     }
     leaf customer-address {
      type inet:ipv4-address;
         description
         "IPv4 Address of customer side.";
     }
     leaf prefix-length {
      type uint8 {
       range "0..32";
      }
     description
     "Subnet prefix length expressed in bits.
     It is applied to both provider-address
     and customer-address.";
     }
     description
     "Describes IPv4 addresses used.";
    }
    description
    "IPv4-specific parameters.";
   }
   container ipv6 {
    if-feature ipv6;
    leaf address-allocation-type {
     type identityref {
      base address-allocation-type;
     }
     description
     "Defines how addresses are allocated.
     If there is no value for the address
     allocation type, then IPv6 is
     not enabled.";
    }

   container provider-dhcp {
      when "derived-from-or-self(../address-allocation-type, "+
      "'l3vpn-svc:provider-dhcp') "+
      "or derived-from-or-self(../address-allocation-type, "+
      "'l3vpn-svc:provider-dhcp-slaac')" {
      description
      "Only applies when addresses are allocated by DHCP.";
       }
          leaf provider-address {
           type inet:ipv6-address;
           description
           "Address of the provider side.  If provider-address
           is not specified, then prefix length should not be
           specified either.  It also implies provider-dhcp



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           allocation is not enabled.  If provider-address is
           specified, then prefix length may or may
           not be specified.";
         }
      leaf prefix-length {
       type uint8 {
       range "0..128";
       }
           must "(../provider-address)" {
             error-message
             "If prefix length is specified, provider-address
             must also be specified.";
             description
             "If prefix length is specified, provider-address
             must also be specified.";
            }
       description
       "Subnet prefix length expressed in bits.  If not
       specified, or specified as zero, this means the
       customer leaves the actual prefix length value
       to the provider.";
     }
        choice address-assign {
         default number;
         case number {
          leaf number-of-dynamic-address {
           type uint16;
           default 1;
           description
           "Describes the number of IP addresses the customer
           requires.";
          }
         }
         case explicit {
          container customer-addresses {
           list address-group {
                 key "group-id";
                 leaf group-id {
                 type string;
                 description
                 "Group-id for the address range from
                 start-address to end-address.";
             }
                 leaf start-address {
                  type inet:ipv6-address;
                  description
                  "First address.";
                  }



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                 leaf end-address {
                  type inet:ipv6-address;
                  description
                  "Last address.";
                  }
                 description
                 "Describes IP addresses allocated by DHCP.  When only
                 start-address or only end-address is present, it
                 represents a single address.  When both start-address
                 and end-address are specified, it implies a range
                 inclusive of both addresses.  If no address is
                 specified, it implies customer addresses group is
                 not supported.";
          }
           description
           "Container for customer addresses allocated by DHCP.";
         }
        }
         description
         "Choice for the way to assign addresses.";
        }
         description
         "DHCP allocated addresses related parameters.";
        }
   container dhcp-relay {
    when "derived-from-or-self(../address-allocation-type, "+
         "'l3vpn-svc:provider-dhcp-relay')" {
      description
      "Only applies when the provider is required
      to implement DHCP relay function.";
      }
        leaf provider-address {
         type inet:ipv6-address;
          description
          "Address of the provider side.  If provider-address is
          not specified, then prefix length should not be
          specified either.  It also implies provider-dhcp
          allocation is not enabled.  If provider address
          is specified, then prefix length may or may
          not be specified.";
          }
        leaf prefix-length {
         type uint8 {
          range "0..128";
          }
         must "(../provider-address)" {
          error-message
           "If prefix length is specified, provider-address



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           must also be specified.";
          description
          "If prefix length is specified, provider-address
          must also be specified.";
           }
         description
         "Subnet prefix length expressed in bits.  If not
         specified, or specified as zero, this means the
         customer leaves the actual prefix length value
         to the provider.";
         }
    container customer-dhcp-servers {
     leaf-list server-ip-address {
      type inet:ipv6-address;
       description
       "This node contains the IP address of
       the customer DHCP server.  If the DHCP relay
       function is implemented by the
       provider, this node contains the
       configured value.";
     }
      description
      "Container for list of customer DHCP servers.";
     }
    description
    "DHCP relay provided by operator.";
    }
   container addresses {
    when "derived-from-or-self(../address-allocation-type, "+
        "'l3vpn-svc:static-address')" {
     description
     "Only applies when protocol allocation type is static.";
     }
    leaf provider-address {
     type inet:ipv6-address;
      description
      "IPv6 Address of the provider side.  When the protocol
      allocation type is static, the provider address
      must be configured.";
     }
    leaf customer-address {
     type inet:ipv6-address;
      description
      "The IPv6 Address of the customer side.";
     }
    leaf prefix-length {
     type uint8 {
      range "0..128";



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     }
     description
     "Subnet prefix length expressed in bits.
     It is applied to both provider-address and
     customer-address.";
    }
    description
    "Describes IPv6 addresses used.";
    }
    description
    "IPv6-specific parameters.";
   }
   container oam {
    container bfd {
     if-feature bfd;
     leaf enabled {
      type boolean;
      default false;
      description
      "If true, BFD activation is required.";
     }
     choice holdtime {
      default fixed;
      case fixed {
       leaf fixed-value {
        type uint32;
        units msec;
         description
         "Expected BFD holdtime expressed in msec.  The customer
         may impose some fixed values for the holdtime period
         if the provider allows the customer use this function.
         If the provider doesn't allow the customer to use this
         function, the fixed-value will not be set.";
       }
      }
      case profile {
       leaf profile-name {
        type leafref {
         path "/l3vpn-svc/vpn-profiles/valid-provider-identifiers/"+
                 "bfd-profile-identifier/id";
        }
        description
        "Well-known SP profile name.  The provider can propose
        some profiles to the customer, depending on the service
        level the customer wants to achieve.  Profile names
        must be communicated to the customer.";
       }
       description



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       "Well-known SP profile.";
      }
      description
      "Choice for holdtime flavor.";
     }
     description
     "Container for BFD.";
    }
    description
    "Defines the Operations, Administration, and Maintenance (OAM)
    mechanisms used on the connection.  BFD is set as a fault
    detection mechanism, but the 'oam' container can easily
    be augmented by other mechanisms";
   }
   description
   "Defines connection parameters.";
  }
  description
  "This grouping defines IP connection parameters.";
 }
 grouping site-service-multicast {
  container multicast {
   if-feature multicast;
   leaf multicast-site-type {
    type enumeration {
     enum receiver-only {
      description
      "The site only has receivers.";
     }
     enum source-only {
      description
      "The site only has sources.";
     }
     enum source-receiver {
      description
      "The site has both sources and receivers.";
     }
    }
    default source-receiver;
    description
    "Type of multicast site.";
   }
   container multicast-address-family {
    leaf ipv4 {
     if-feature ipv4;
     type boolean;
     default false;
     description



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     "Enables IPv4 multicast.";
    }
    leaf ipv6 {
     if-feature ipv6;
     type boolean;
     default false;
     description
     "Enables IPv6 multicast.";
    }
    description
    "Defines protocol to carry multicast.";
    }
   leaf protocol-type {
    type enumeration {
     enum host {
      description
      "Hosts are directly connected to the provider network.
      Host protocols such as IGMP or MLD are required.";
     }
     enum router {
      description
      "Hosts are behind a customer router.
      PIM will be implemented.";
     }
     enum both {
      description
      "Some hosts are behind a customer router, and
      some others are directly connected to the
      provider network.  Both host and routing protocols
      must be used.  Typically, IGMP and PIM will be
      implemented.";
     }
    }
    default "both";
    description
    "Multicast protocol type to be used with the customer site.";
   }
   description
   "Multicast parameters for the site.";
  }
  description
  "Multicast parameters for the site.";
 }
 grouping site-management {
  container management {
   leaf type {
    type identityref {
     base management;



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    }
    mandatory true;
    description
    "Management type of the connection.";
   }
   description
   "Management configuration.";
  }
  description
  "Management parameters for the site.";
 }
 grouping site-devices {
  container devices {
   when "derived-from-or-self(../management/type, "+
   "'l3vpn-svc:provider-managed') or "+
   "derived-from-or-self(../management/type, 'l3vpn-svc:co-managed')" {
   description
   "Applicable only for provider-managed or
   co-managed device.";
  }
  list device {
   key device-id;
   leaf device-id {
    type svc-id;
    description
    "Identifier for the device.";
   }
   leaf location {
    type leafref {
     path "../../../locations/"+
     "location/location-id";
    }
    mandatory true;
    description
     "Location of the device.";
    }
   container management {
    when "derived-from-or-self(../../../management/type,"+
      "'l3vpn-svc:co-managed')" {
      description
       "Applicable only for co-managed device.";
     }
    leaf address-family {
     type address-family;
     description
     "Address family used for management.";
    }
    leaf address {



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         when "(../address-family)" {
           description
           "If address-family is specified, then address should
           also be specified.  If address-family is not specified,
           then address should also not be specified.";
           }
         type inet:ip-address;
         mandatory true;
     description
     "Management address.";
     }
    description
     "Management configuration.  Applicable only for
      co-managed device.";
    }
    description
    "List of devices requested by customer.";
   }
   description
   "Device configuration.";
  }
  description
  "Grouping for device allocation.";
 }
 grouping site-vpn-flavor {
  leaf site-vpn-flavor {
   type identityref {
    base site-vpn-flavor;
   }
   default site-vpn-flavor-single;
   description
   "Defines the way the VPN multiplexing is done, e.g., whether
   the site belongs to a single VPN site or a multiVPN; or, in the case
   of a multiVPN, whether the logical accesses of the sites belong
   to the same set of VPNs or each logical access maps to
   different VPNs.";
  }
  description
  "Grouping for site VPN flavor.";
 }
 grouping site-vpn-policy {
  container vpn-policies {
   list vpn-policy {
    key vpn-policy-id;
    leaf vpn-policy-id {
     type svc-id;
     description
     "Unique identifier for the VPN policy.";



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    }
    list entries {
     key id;
     leaf id {
      type svc-id;
      description
      "Unique identifier for the policy entry.";
     }
     container filters {
      list filter {
       key type;
       ordered-by user;
       leaf type {
        type identityref {
         base vpn-policy-filter-type;
         }
        description
        "Type of VPN Policy filter.";
        }
        leaf-list lan-tag {
        when "derived-from-or-self(../type, 'l3vpn-svc:lan')" {
         description
         "Only applies when the VPN Policy filter is a
         LAN Tag filter.";
        }
         if-feature lan-tag;
         type string;
         description
         "List of 'lan-tag' items to be matched.  LAN Tag
         is an Internal tag to be used in VPN policies ";
        }
        leaf-list ipv4-lan-prefix {
        when "derived-from-or-self(../type, 'l3vpn-svc:ipv4')" {
          description
          "Only applies when VPN Policy filter is IPv4 Prefix filter.";
         }
         if-feature ipv4;
         type inet:ipv4-prefix;
         description
         "List of IPv4 prefixes as LAN Prefixes to be matched.";
        }
        leaf-list ipv6-lan-prefix {
        when "derived-from-or-self(../type, 'l3vpn-svc:ipv6')" {
        description
        "Only applies when VPN Policy filter is IPv6 Prefix filter.";
         }
         if-feature ipv6;
         type inet:ipv6-prefix;



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         description
         "List of IPv6 prefixes as LAN prefixes to be matched.";
        }
         description
         "List of filters used on the site.  This list can
         be augmented.";
      }
      description
      "If a more-granular VPN attachment is necessary, filtering can
      be used.  If used, it permits the splitting of site LANs among
      multiple VPNs.  The Site LAN can be split based on either LAN
      Tag or LAN prefix.  If no filter is used, all the LANs will be
      part of the same VPNs with the same role.";
     }
     list vpn {
      key vpn-id;
      leaf vpn-id {
       type leafref {
        path "/l3vpn-svc/vpn-services/"+
         "vpn-service/vpn-id";
       }
       mandatory true;
       description
       "Reference to an IP VPN.";
      }
      leaf site-role {
       type identityref {
        base site-role;
       }
       default any-to-any-role;
       description
       "Role of the site in the IP VPN.";
      }
      description
      "List of VPNs the LAN is associated with.";
     }
     description
     "List of entries for export policy.";
    }
    description
    "List of VPN policies.";
   }
   description
   "VPN policy.";
  }
  description
  "VPN policy parameters for the site.";
 }



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 grouping site-maximum-routes {
  container maximum-routes {
   list address-family {
    key af;
    leaf af {
     type address-family;
     description
     "Address family.";
    }
    leaf maximum-routes {
     type uint32;
     description
     "Maximum prefixes the VRF can accept
     for this address family.";
    }
    description
    "List of address families.";
   }
   description
   "Defines 'maximum-routes' for the VRF.";
  }
  description
  "Defines 'maximum-routes' for the site.";
 }
 grouping site-security {
  container security {
   uses site-security-authentication;
   uses site-security-encryption;
   description
   "Site-specific security parameters.";
  }
  description
  "Grouping for security parameters.";
 }
 grouping site-service {
  container service {
   uses site-service-qos-profile;
   uses site-service-mpls;
   uses site-service-multicast;
   description
   "Service parameters on the attachment.";
  }
  description
  "Grouping for service parameters.";
 }
 grouping site-network-access-service {
  container service {
   uses site-service-basic;



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   uses site-service-qos-profile;
   uses site-service-mpls;
   uses site-service-multicast;
   description
   "Service parameters on the attachment.";
  }
  description
  "Grouping for service parameters.";
 }
 grouping vpn-extranet {
  container extranet-vpns {
   if-feature extranet-vpn;
   list extranet-vpn {
    key vpn-id;
    leaf vpn-id {
     type svc-id;
     description
     "Identifies the target VPN the local VPN want to access.";
    }
    leaf local-sites-role {
     type identityref {
      base site-role;
     }
     default any-to-any-role;
     description
     "This describes the role of the
     local sites in the target VPN topology.  In the any-to-any VPN
     service topology, the local sites must have the same role, which
     will be 'any-to-any-role'.  In the Hub-and-Spoke VPN service
     topology or the Hub-and-Spoke disjoint VPN service topology,
     the local sites must have a Hub role or a Spoke role.";
    }
    description
    "List of extranet VPNs or target VPNs the local VPN is
    attached to.";
   }
   description
   "Container for extranet VPN configuration.";
  }
  description
  "Grouping for extranet VPN configuration.
  This provides an easy way to interconnect
  all sites from two VPNs.";
 }
 grouping site-attachment-availability {
  container availability {
   leaf access-priority {
    type uint32;



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    default 100;
    description
    "Defines the priority for the access.
    The higher the access-priority value,
    the higher the preference of the
    access will be.";
   }
   description
   "Availability parameters (used for multihoming).";
  }
  description
  "Defines availability parameters for a site.";
 }
 grouping access-vpn-policy {
  container vpn-attachment {
   choice attachment-flavor {
    case vpn-policy-id {
     leaf vpn-policy-id {
      type leafref {
       path "../../../../"+
        "vpn-policies/vpn-policy/"+
        "vpn-policy-id";
      }
      description
      "Reference to a VPN policy.  When referencing VPN
      policy for attachment, the vpn-policy-id must be
      configured.";
     }
    }
    case vpn-id {
     leaf vpn-id {
      type leafref {
       path "/l3vpn-svc/vpn-services"+
        "/vpn-service/vpn-id";
      }
      description
      "Reference to an IP VPN.  Referencing a vpn-id provides
      an easy way to attach a particular logical access to
      a VPN.  In this case, vpn-id must be configured.";
     }
     leaf site-role {
      type identityref {
       base site-role;
      }
      default any-to-any-role;
      description
      "Role of the site in the IP VPN.  When referencing a vpn-id,
      the site-role setting must be added to express the role of



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RFC 8299       YANG Data Model for L3VPN Service Delivery   January 2018


      the site in the target VPN service topology.";
     }
    }
    mandatory true;
    description
    "Choice for VPN attachment flavor.  A choice is implemented
    to allow the user to choose the flavor that provides the
    best fit.";
   }
   description
   "Defines VPN attachment of a site.";
  }
  description
  "Defines the VPN attachment rules for
  a site's logical access.";
 }
 grouping vpn-profile-cfg {
  container valid-provider-identifiers {
   list cloud-identifier {
    if-feature cloud-access;
    key id;
    leaf id {
     type string;
     description
     "Identification of cloud service.
     Local administration meaning.";
    }
    description
    "List for Cloud Identifiers.";
   }
   list encryption-profile-identifier {
    key id;
    leaf id {
     type string;
     description
     "Identification of the SP encryption profile
     to be used.  Local administration meaning.";
    }
    description
    "List for encryption profile identifiers.";
   }
   list qos-profile-identifier {
    key id;
    leaf id {
     type string;
     description
     "Identification of the QoS Profile to be used.
     Local administration meaning.";



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RFC 8299       YANG Data Model for L3VPN Service Delivery   January 2018


    }
    description
    "List for QoS Profile Identifiers.";
   }
   list bfd-profile-identifier {
    key id;
    leaf id {
     type string;
     description
     "Identification of the SP BFD Profile to be used.
     Local administration meaning.";
    }
    description
    "List for BFD Profile identifiers.";
   }
     nacm:default-deny-write;
     description
     "Container for Valid Provider Identifies.";
  }
   description
   "Grouping for VPN Profile configuration.";
 }
 grouping vpn-svc-cfg {
  leaf vpn-id {
   type svc-id;
   description
   "VPN identifier.  Local administration meaning.";
  }
  leaf customer-name {
   type string;
   description
   "Name of the customer that actually uses the VPN service.
   In the case that any intermediary (e.g., Tier-2 provider
   or partner) sells the VPN service to their end user
   on behalf of the original service provider (e.g., Tier-1
   provider), the original service provider may require the
   customer name to provide smooth activation/commissioning
   and operation for the service.";
  }
  leaf vpn-service-topology {
   type identityref {
    base vpn-topology;
   }
   default any-to-any;
   description
   "VPN service topology.";
  }
  uses vpn-service-cloud-access;



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  uses vpn-service-multicast;
  uses vpn-service-mpls;
  uses vpn-extranet;
  description
  "Grouping for VPN service configuration.";
 }
 grouping site-top-level-cfg {
  uses operational-requirements;
  uses customer-location-info;
  uses site-devices;
  uses site-diversity;
  uses site-management;
  uses site-vpn-policy;
  uses site-vpn-flavor;
  uses site-maximum-routes;
  uses site-security;
  uses site-service;
  uses site-protection;
  uses site-routing;
  description
  "Grouping for site top-level configuration.";
 }
 grouping site-network-access-top-level-cfg {
  leaf site-network-access-type {
   type identityref {
    base site-network-access-type;
   }
   default point-to-point;
   description
   "Describes the type of connection, e.g.,
   point-to-point or multipoint.";
  }
  choice location-flavor {
   case location {
    when "derived-from-or-self(../../management/type, "+
     "'l3vpn-svc:customer-managed')" {
     description
     "Applicable only for customer-managed device.";
    }
    leaf location-reference {
     type leafref {
      path "../../../locations/location/location-id";
     }
     description
     "Location of the site-network-access.";
    }
   }
   case device {



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    when "derived-from-or-self(../../management/type, "+
     "'l3vpn-svc:provider-managed') or "+
     "derived-from-or-self(../../management/type, "+
     "'l3vpn-svc:co-managed')" {
     description
     "Applicable only for provider-managed or co-managed device.";
    }
    leaf device-reference {
     type leafref {
      path "../../../devices/device/device-id";
     }
     description
     "Identifier of CE to use.";
    }
   }
   mandatory true;
   description
   "Choice of how to describe the site's location.";
  }
  uses access-diversity;
  uses site-attachment-bearer;
  uses site-attachment-ip-connection;
  uses site-security;
  uses site-network-access-service;
  uses site-routing;
  uses site-attachment-availability;
  uses access-vpn-policy;
  description
  "Grouping for site network access top-level configuration.";
 }
 /* Main blocks */
 container l3vpn-svc {
  container vpn-profiles {
   uses vpn-profile-cfg;
    description
    "Container for VPN Profiles.";
  }
  container vpn-services {
   list vpn-service {
    key vpn-id;
    uses vpn-svc-cfg;
    description
    "List of VPN services.";
   }
   description
   "Top-level container for the VPN services.";
  }
  container sites {



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   list site {
    key site-id;
    leaf site-id {
     type svc-id;
     description
     "Identifier of the site.";
    }
    uses site-top-level-cfg;
    uses operational-requirements-ops;
    container site-network-accesses {
     list site-network-access {
      key site-network-access-id;
      leaf site-network-access-id {
       type svc-id;
       description
       "Identifier for the access.";
      }
      uses site-network-access-top-level-cfg;
      description
      "List of accesses for a site.";
     }
     description
     "List of accesses for a site.";
    }
    description
    "List of sites.";
   }
   description
   "Container for sites.";
  }
  description
  "Main container for L3VPN service configuration.";
 }
}
<CODE ENDS>
















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RFC 8299       YANG Data Model for L3VPN Service Delivery   January 2018


10.  Security Considerations

  The YANG module specified in this document defines a schema for data
  that is designed to be accessed via network management protocols such
  as NETCONF [RFC6241] or RESTCONF [RFC8040].  The lowest NETCONF layer
  is the secure transport layer, and the mandatory-to-implement secure
  transport is Secure Shell (SSH) [RFC6242].  The lowest RESTCONF layer
  is HTTPS, and the mandatory-to-implement secure transport is TLS
  [RFC5246].

  The NETCONF access control model [RFC6536]provides the means to
  restrict access for particular NETCONF or RESTCONF users to a
  preconfigured subset of all available NETCONF or RESTCONF protocol
  operations and content.

  There are a number of data nodes defined in this YANG module that are
  writable/creatable/deletable (i.e., config true, which is the
  default).  These data nodes may be considered sensitive or vulnerable
  in some network environments.  Write operations (e.g., edit-config)
  to these data nodes without proper protection can have a negative
  effect on network operations.  These are the subtrees and data nodes
  and their sensitivity/vulnerability:

  o  /l3vpn-svc/vpn-services/vpn-service

     The entries in the list above include the whole vpn service
     configurations which the customer subscribes, and indirectly
     create or modify the PE and CE device configurations.  Unexpected
     changes to these entries could lead to service disruption and/or
     network misbehavior.

  o  /l3vpn-svc/sites/site

     The entries in the list above include the customer site
     configurations.  As above, unexpected changes to these entries
     could lead to service disruption and/or network misbehavior.

  Some of the readable data nodes in this YANG module may be considered
  sensitive or vulnerable in some network environments.  It is thus
  important to control read access (e.g., via get, get-config, or
  notification) to these data nodes.  These are the subtrees and data
  nodes and their sensitivity/vulnerability:

  o  /l3vpn-svc/vpn-services/vpn-service

  o  /l3vpn-svc/sites/site





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  The entries in the lists above include customer-proprietary or
  confidential information, e.g., customer-name, site location, what
  service the customer subscribes.

  The data model defines some security parameters than can be extended
  via augmentation as part of the customer service request; those
  parameters are described in Section 6.9.

11.  IANA Considerations

  IANA has assigned a new URI from the "IETF XML Registry" [RFC3688].

            URI: urn:ietf:params:xml:ns:yang:ietf-l3vpn-svc
            Registrant Contact: The IESG
            XML: N/A; the requested URI is an XML namespace.

  IANA has recorded a YANG module name in the "YANG Module Names"
  registry [RFC6020] as follows:

          Name: ietf-l3vpn-svc
          Namespace: urn:ietf:params:xml:ns:yang:ietf-l3vpn-svc
          Prefix: l3vpn-svc
          Reference: RFC 8299

  IANA previously assigned the URI and YANG module as described in
  [RFC8049].  IANA has updated the references for these entries to
  refer to this document.

12.  References

12.1.  Normative References

  [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
             Requirement Levels", BCP 14, RFC 2119,
             DOI 10.17487/RFC2119, March 1997,
             <https://www.rfc-editor.org/info/rfc2119>.

  [RFC3022]  Srisuresh, P. and K. Egevang, "Traditional IP Network
             Address Translator (Traditional NAT)", RFC 3022,
             DOI 10.17487/RFC3022, January 2001,
             <https://www.rfc-editor.org/info/rfc3022>.

  [RFC3688]  Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
             DOI 10.17487/RFC3688, January 2004,
             <https://www.rfc-editor.org/info/rfc3688>.






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RFC 8299       YANG Data Model for L3VPN Service Delivery   January 2018


  [RFC4364]  Rosen, E. and Y. Rekhter, "BGP/MPLS IP Virtual Private
             Networks (VPNs)", RFC 4364, DOI 10.17487/RFC4364, February
             2006, <https://www.rfc-editor.org/info/rfc4364>.

  [RFC4577]  Rosen, E., Psenak, P., and P. Pillay-Esnault, "OSPF as the
             Provider/Customer Edge Protocol for BGP/MPLS IP Virtual
             Private Networks (VPNs)", RFC 4577, DOI 10.17487/RFC4577,
             June 2006, <https://www.rfc-editor.org/info/rfc4577>.

  [RFC4862]  Thomson, S., Narten, T., and T. Jinmei, "IPv6 Stateless
             Address Autoconfiguration", RFC 4862,
             DOI 10.17487/RFC4862, September 2007,
             <https://www.rfc-editor.org/info/rfc4862>.

  [RFC5246]  Dierks, T. and E. Rescorla, "The Transport Layer Security
             (TLS) Protocol Version 1.2", RFC 5246,
             DOI 10.17487/RFC5246, August 2008,
             <https://www.rfc-editor.org/info/rfc5246>.

  [RFC6020]  Bjorklund, M., Ed., "YANG - A Data Modeling Language for
             the Network Configuration Protocol (NETCONF)", RFC 6020,
             DOI 10.17487/RFC6020, October 2010,
             <https://www.rfc-editor.org/info/rfc6020>.

  [RFC6241]  Enns, R., Ed., Bjorklund, M., Ed., Schoenwaelder, J., Ed.,
             and A. Bierman, Ed., "Network Configuration Protocol
             (NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011,
             <https://www.rfc-editor.org/info/rfc6241>.

  [RFC6242]  Wasserman, M., "Using the NETCONF Protocol over Secure
             Shell (SSH)", RFC 6242, DOI 10.17487/RFC6242, June 2011,
             <https://www.rfc-editor.org/info/rfc6242>.

  [RFC6513]  Rosen, E., Ed. and R. Aggarwal, Ed., "Multicast in MPLS/
             BGP IP VPNs", RFC 6513, DOI 10.17487/RFC6513, February
             2012, <https://www.rfc-editor.org/info/rfc6513>.

  [RFC6536]  Bierman, A. and M. Bjorklund, "Network Configuration
             Protocol (NETCONF) Access Control Model", RFC 6536,
             DOI 10.17487/RFC6536, March 2012,
             <https://www.rfc-editor.org/info/rfc6536>.

  [RFC7950]  Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language",
             RFC 7950, DOI 10.17487/RFC7950, August 2016,
             <https://www.rfc-editor.org/info/rfc7950>.






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RFC 8299       YANG Data Model for L3VPN Service Delivery   January 2018


  [RFC8040]  Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF
             Protocol", RFC 8040, DOI 10.17487/RFC8040, January 2017,
             <https://www.rfc-editor.org/info/rfc8040>.

  [RFC8049]  Litkowski, S., Tomotaki, L., and K. Ogaki, "YANG Data
             Model for L3VPN Service Delivery", RFC 8049,
             DOI 10.17487/RFC8049, February 2017,
             <https://www.rfc-editor.org/info/rfc8049>.

  [RFC8174]  Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
             2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
             May 2017, <https://www.rfc-editor.org/info/rfc8174>.

12.2.  Informative References

  [ACL-YANG] Jethanandani, M., Huang, L., Agarwal, S., and D. Blair,
             "Network Access Control List (ACL) YANG Data Model", Work
             in Progress, draft-ietf-netmod-acl-model-14, October 2017.

  [RFC4026]  Andersson, L. and T. Madsen, "Provider Provisioned Virtual
             Private Network (VPN) Terminology", RFC 4026,
             DOI 10.17487/RFC4026, March 2005,
             <https://www.rfc-editor.org/info/rfc4026>.

  [RFC4110]  Callon, R. and M. Suzuki, "A Framework for Layer 3
             Provider-Provisioned Virtual Private Networks (PPVPNs)",
             RFC 4110, DOI 10.17487/RFC4110, July 2005,
             <https://www.rfc-editor.org/info/rfc4110>.

  [RFC4760]  Bates, T., Chandra, R., Katz, D., and Y. Rekhter,
             "Multiprotocol Extensions for BGP-4", RFC 4760,
             DOI 10.17487/RFC4760, January 2007,
             <https://www.rfc-editor.org/info/rfc4760>.

  [RFC8277]  Rosen, E., "Using BGP to Bind MPLS Labels to Address
             Prefixes", RFC 8277, DOI 10.17487/RFC8277, October 2017,
             <https://www.rfc-editor.org/info/rfc8277>.














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Acknowledgements

  Maxim Klyus, Luis Miguel Contreras, Gregory Mirsky, Zitao Wang, Jing
  Zhao, Kireeti Kompella, Eric Rosen, Aijun Wang, Michael Scharf,
  Xufeng Liu, David Ball, Lucy Yong, Jean-Philippe Landry, and Andrew
  Leu provided useful review to this document.

  Jan Lindblad reviewed RFC 8049 and found some bugs, and his thorough
  YANG Doctor review on the YANG Module is valuable input.  David Ball
  also provided a second review on RFC 8049.

  Many thanks to these people.

Contributors

  The authors would like to thank Rob Shakir for his major
  contributions to the initial modeling and use cases.

  Adrian Farrel prepared the editorial revisions for this document.

Authors' Addresses

  Qin Wu (editor)
  Huawei Technologies

  Email: [email protected]


  Stephane Litkowski
  Orange Business Services

  Email: [email protected]


  Luis Tomotaki
  Verizon

  Email: [email protected]


  Kenichi Ogaki
  KDDI Corporation

  Email: [email protected]







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