Internet Engineering Task Force (IETF)                    F. Jounay, Ed.
Request for Comments: 7338                                     Orange CH
Category: Informational                                   Y. Kamite, Ed.
ISSN: 2070-1721                                       NTT Communications
                                                               G. Heron
                                                          Cisco Systems
                                                               M. Bocci
                                                         Alcatel-Lucent
                                                         September 2014


    Requirements and Framework for Point-to-Multipoint Pseudowires
                  over MPLS Packet Switched Networks

Abstract

  This document presents a set of requirements and a framework for
  providing a point-to-multipoint pseudowire (PW) over MPLS Packet
  Switched Networks.  The requirements identified in this document are
  related to architecture, signaling, and maintenance aspects of point-
  to-multipoint PW operation.  They are proposed as guidelines for the
  standardization of such mechanisms.  Among other potential
  applications, point-to-multipoint PWs can be used to optimize the
  support of multicast Layer 2 services (Virtual Private LAN Service
  and Virtual Private Multicast Service).

Status of This Memo

  This document is not an Internet Standards Track specification; it is
  published for informational purposes.

  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).  Not all documents
  approved by the IESG are a candidate for any level of Internet
  Standard; see Section 2 of RFC 5741.

  Information about the current status of this document, any errata,
  and how to provide feedback on it may be obtained at
  http://www.rfc-editor.org/info/rfc7338.










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Copyright Notice

  Copyright (c) 2014 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
  (http://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
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  the Trust Legal Provisions and are provided without warranty as
  described in the Simplified BSD License.

  This document may contain material from IETF Documents or IETF
  Contributions published or made publicly available before November
  10, 2008.  The person(s) controlling the copyright in some of this
  material may not have granted the IETF Trust the right to allow
  modifications of such material outside the IETF Standards Process.
  Without obtaining an adequate license from the person(s) controlling
  the copyright in such materials, this document may not be modified
  outside the IETF Standards Process, and derivative works of it may
  not be created outside the IETF Standards Process, except to format
  it for publication as an RFC or to translate it into languages other
  than English.

























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Table of Contents

  1. Introduction ....................................................3
     1.1. Problem Statement ..........................................3
     1.2. Scope of This Document .....................................4
     1.3. Conventions Used in This Document ..........................4
  2. Definitions .....................................................5
     2.1. Acronyms ...................................................5
     2.2. Terminology ................................................5
  3. P2MP PW Requirements ............................................6
     3.1. Reference Model ............................................6
     3.2. P2MP PW and Underlying Layer ...............................7
     3.3. P2MP PW Construction .......................................9
     3.4. P2MP PW Signaling Requirements ............................10
          3.4.1. P2MP PW Identifier .................................10
          3.4.2. PW Type Mismatch ...................................10
          3.4.3. Interface Parameters Sub-TLV .......................10
          3.4.4. Leaf Grafting/Pruning ..............................10
          3.4.5. Failure Detection and Reporting ....................11
          3.4.6. Protection and Restoration .........................11
          3.4.7. Scalability ........................................13
  4. Backward Compatibility .........................................13
  5. Security Considerations ........................................13
  6. References .....................................................14
     6.1. Normative References ......................................14
     6.2. Informative References ....................................14
  7. Acknowledgments ................................................15
  8. Contributors ...................................................16

1.  Introduction

1.1.  Problem Statement

  As defined in the pseudowire architecture [RFC3985], a pseudowire
  (PW) is a mechanism that emulates the essential attributes of a
  telecommunications service (such as a T1 leased line or Frame Relay)
  over an IP or MPLS Packet Switched Network (PSN).  It provides a
  single service that is perceived by its user as an unshared link or
  circuit of the chosen service.  A pseudowire is used to transport
  Layer 1 or Layer 2 traffic (e.g., Ethernet, Time-Division
  Multiplexing (TDM), ATM, and Frame Relay) over a Layer 3 PSN.
  Pseudowire Emulation Edge-to-Edge (PWE3) operates "edge to edge" to
  provide the required connectivity between the two endpoints of the
  PW.

  The point-to-multipoint (P2MP) topology described in [VPMS-REQS] and
  required to provide P2MP Layer 2 VPN service can be achieved using
  one or more P2MP PWs.  The use of PW encapsulation enables P2MP



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  services to transport Layer 1 or Layer 2 data.  This could be
  achieved using a set of point-to-point PWs, with traffic replication
  at the Root Provider Edge (PE), but at the cost of bandwidth
  efficiency, as duplicate traffic would be carried multiple times on
  shared links.

  This document defines the requirements for a point-to-multipoint PW
  (P2MP PW).  A P2MP PW is a mechanism that emulates the essential
  attributes of a P2MP telecommunications service such as a P2MP ATM
  Virtual Circuit over a Packet Switched Network.

  The required functions of P2MP PWs include encapsulating service-
  specific Protocol Data Units (PDUs) arriving at an ingress Attachment
  Circuit (AC), carrying them across a tunnel to one or more egress
  ACs, managing their timing and order, and any other operations
  required to emulate the behavior and characteristics of the service
  as faithfully as possible.

1.2.  Scope of This Document

  The document describes the general architecture of P2MP PW with a
  reference model, mentions the notion of data encapsulation, and
  outlines specific requirements for the setup and maintenance of a
  P2MP PW.  In this document, the requirements focus on the Single-
  Segment PW model.  The requirements for realizing P2MP PW in the
  Multi-Segment PW model [RFC5254] are left for further study.  This
  document refers to [RFC3916] for other aspects of P2MP PW
  implementation, such as "Packet Processing" (Section 4 of that
  document) and "Faithfulness of Emulated Services" (Section 7 of that
  document).

1.3.  Conventions Used in This Document

  Although this is a requirements specification not a protocol
  specification, the key words "MUST", "MUST NOT", "REQUIRED", "SHALL",
  "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and
  "OPTIONAL" in this document are to be interpreted to apply to
  protocol solutions designed to meet these requirements as described
  in [RFC2119].












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2.  Definitions

2.1.  Acronyms

  P2P:   Point-to-Point
  P2MP:  Point-to-Multipoint
  PW:    Pseudowire
  PSN:   Packet Switched Network
  SS-PW: Single-Segment Pseudowire

2.2.  Terminology

  This document uses terminology described in [RFC5659].  It also
  introduces additional terms needed in the context of P2MP PW.

  P2MP PW (also referred to as PW tree):
     Point-to-Multipoint Pseudowire.  A PW attached to a source
     Customer Edge (CE) used to distribute Layer 1 or Layer 2 traffic
     to a set of one or more receiver CEs.  The P2MP PW is
     unidirectional (i.e., carrying traffic from Root PE to Leaf PEs)
     and optionally supports a return path.

  P2MP SS-PW:
     Point-to-Multipoint Single-Segment Pseudowire.  A single-segment
     P2MP PW set up between the Root PE attached to the source CE and
     the Leaf PEs attached to the receiver CEs.  The P2MP SS-PW uses
     P2MP Label Switched Paths (LSPs) as PSN tunnels.

  Root PE:
     P2MP PW Root Provider Edge.  The PE attached to the traffic source
     CE for the P2MP PW via an Attachment Circuit (AC).

  Leaf PE:
     P2MP PW Leaf Provider Edge.  A PE attached to a set of one or more
     traffic receiver CEs, via ACs.  The Leaf PE replicates traffic to
     the CEs based on its Forwarder function [RFC3985].

  P2MP PSN Tunnel:
     In the P2MP SS-PW topology, the PSN tunnel is a general term
     indicating a virtual P2MP connection between the Root PE and the
     Leaf PEs.  A P2MP tunnel may potentially carry multiple P2MP PWs
     inside (aggregation).  This document uses terminology from the
     document describing the MPLS multicast architecture [RFC5332] for
     MPLS PSN.







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3.  P2MP PW Requirements

3.1.  Reference Model

  As per the definition in [RFC3985], a pseudowire (PW) both originates
  and terminates on the edge of the same packet switched network (PSN).
  The PW label is unchanged between the originating and terminating
  Provider Edges (PEs).  This is also known as a single-segment
  pseudowire (SS-PW) -- the most fundamental network model of PWE3.

  A P2MP PW can be defined as point-to-multipoint connectivity from a
  Root PE connected to a traffic source CE to one or more Leaf PEs
  connected to traffic receiver CEs.  It is considered to be an
  extended architecture of the existing P2P SS-PW technology.

  Figure 1 describes the P2MP PW reference model that is derived from
  [RFC3985] to support P2MP emulated services.

                 |<-------------P2MP PW------------->|
         Native  |                                   |  Native
  ROOT   Service |    |<----P2MP PSN tunnel --->|    |  Service  LEAF
   V     (AC)    V    V                         V    V   (AC)      V
           |     +----+         +-----+         +----+     |
           |     |PE1 |         |  P  |=========|PE2 |AC2  |     +----+
           |     |    |         |   ......PW1.......>|---------->|CE2 |
           |     |    |         |   . |=========|    |     |     +----+
           |     |    |         |   . |         +----+     |
           |     |    |=========|   . |                    |
           |     |    |         |   . |         +----+     |
  +----+   | AC1 |    |         |   . |=========|PE3 |AC3  |     +----+
  |CE1 |-------->|........PW1.............PW1.......>|---------->|CE3 |
  +----+   |     |    |         |   . |=========|    |     |     +----+
           |     |    |         |   . |         +----+     |
           |     |    |=========|   . |                    |
           |     |    |         |   . |         +----+AC4  |     +----+
           |     |    |         |   . |=========|PE4 |---------->|CE4 |
           |     |    |         |   ......PW1.......>|     |     +----+
           |     |    |         |     |=========|    |AC5  |     +----+
           |     |    |         |     |         |    |---------->|CE5 |
           |     +----+         +-----+         +----+     |     +----+

                   Figure 1: P2MP PW Reference Model

  This architecture applies to the case where a P2MP PSN tunnel extends
  between edge nodes of a single PSN domain to transport a
  unidirectional P2MP PW with endpoints at these edge nodes.  In this
  model, a single copy of each PW packet is sent over the PW on the
  P2MP PSN tunnel and is received by all Leaf PEs due to the P2MP



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  nature of the PSN tunnel.  The P2MP PW SHOULD be traffic optimized,
  i.e., only one copy of a P2MP PW packet or PSN tunnel (underlying
  layer) packet is sent on any single link along the P2MP path.  P
  routers participate in P2MP PSN tunnel operation but not in the
  signaling of P2MP PWs.

  The Reference Model outlines the basic pieces of a P2MP PW.  However,
  several levels of replication need to be considered when designing a
  P2MP PW solution:

  -  Ingress PE replication to CEs: traffic is replicated to a set of
     local receiver CEs

  -  P router replication in the core: traffic is replicated by means
     of a P2MP PSN tunnel (P2MP LSP)

  -  Egress PE replication to CEs: traffic is replicated to local
     receiver CEs

  Theoretically, it is also possible to consider Ingress PE replication
  in the core; that is, all traffic is replicated to a set of P2P PSN
  transport tunnels at ingress, not using P router replication at all.

  However, this approach may lead to duplicate copies of each PW packet
  being sent over the same physical link, specifically in the case
  where multiple PSN tunnels transit that physical link.  Hence, this
  approach is not preferred.

  Specific operations that MUST be performed at the PE on the native
  data units are not described here since the required pre-processing
  (Forwarder (FWRD) and Native Service Processing (NSP)) defined in
  Section 4.2 of [RFC3985] is also applicable to P2MP PW.

  P2MP PWs are generally unidirectional, but a Root PE may need to
  receive unidirectional P2P return traffic from any Leaf PE.  For that
  purpose, the P2MP PW solution MAY support an optional return path
  from each Leaf PE to the Root PE.

3.2.  P2MP PW and Underlying Layer

  The definition of MPLS multicast encapsulation [RFC5332] specifies
  the procedure to carry MPLS packets that are to be replicated and a
  copy of the packet sent to each of the specified next hops.  This
  notion is also applicable to a P2MP PW packet carried by a P2MP PSN
  tunnel.

  To be more precise, a P2MP PSN tunnel corresponds to a "point-to-
  multipoint data link or tunnel" described in Section 3 of [RFC5332].



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  Similarly, P2MP PW labels correspond to "the top labels (before
  applying the data link or tunnel encapsulation) of all MPLS packets
  that are transmitted on a particular point-to-multipoint data link or
  tunnel".

  In the P2MP PW architecture using the SS-PW network model, the PW-PDU
  [RFC3985] is replicated by the underlying P2MP PSN tunnel layer.
  Note that the PW label is unchanged, and hidden in switching, by the
  transit P routers.

  In a solution, a P2MP PW MUST be supported over a single P2MP PSN
  tunnel as the underlying layer of traffic distribution.  Figure 2
  gives an example of P2MP PW topology relying on a single P2MP LSP.
  The PW tree is composed of one Root PE (i1) and several Leaf PEs (e1,
  e2, e3, e4).

  The mechanisms for establishing the PSN tunnel are outside the scope
  of this document, as long as they enable the essential attributes of
  the service to be emulated.

                               i1
                               /
                              / \
                             /   \
                            /     \
                           /\      \
                          /  \      \
                         /    \      \
                        /      \    / \
                       e1      e2  e3 e4

         Figure 2: Example of P2MP Underlying Layer for P2MP PW

  A single P2MP PSN tunnel MUST be able to serve the traffic from more
  than one P2MP PW in an aggregated way, i.e., multiplexing.

  A P2MP PW solution MAY support different P2MP PSN tunneling
  technology (e.g., MPLS over GRE [RFC4023] or P2MP MPLS LSP) or
  different setup protocols (e.g., multipoint extensions for LDP (mLDP)
  [RFC6388] and P2MP RSVP-TE [RFC4875]).

  The P2MP LSP associated to the P2MP PW can be selected either by user
  configuration or by dynamically using a multiplexing/demultiplexing
  mechanism.

  The P2MP PW multiplexing SHOULD be used based on the overlap rate
  between P2MP LSP and P2MP PW.  As an example, an existing P2MP LSP
  may attach more leaves than the ones defined as Leaf PEs for a given



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  P2MP PW.  It may be attractive to reuse it to minimize new
  configuration, but using this P2MP LSP would cause non-Leaf PEs
  (i.e., not part of the P2MP PW) to receive unwanted traffic.

  Note: no special configuration is needed for non-Leaf PEs to drop
  that unwanted traffic because they do not have forwarding information
  entries unless they process the setup operation for corresponding
  P2MP PWs (e.g., signaling).

  The operator SHOULD determine whether it is acceptable to partially
  multiplex the P2MP PW onto a P2MP LSP, and a minimum congruency rate
  may be defined to enable the Root PE to make this determination.  The
  congruency rate SHOULD take into account several items, including:

  -  the amount of overlap between the Leaf PEs of the P2MP PW and the
     existing egress PE routers of the P2MP LSP.  If there is a
     complete overlap, the congruency is perfect and the rate is 100%.

  -  the impact on other traffic (e.g., from other VPNs) supported over
     the P2MP LSP.

  With this procedure, a P2MP PW is nested within a P2MP LSP.  This
  allows multiplexing several PWs over a common P2MP LSP.  Prior to the
  P2MP PW signaling phase, the Root PE determines which P2MP LSP will
  be used for this P2MP PW.  The PSN tunnel can be an existing PSN
  tunnel or the Root PE can create a new P2MP PSN tunnel.  Note that
  the ingress PE may modify or re-create an existing P2MP PSN tunnel in
  order to add one or more leaf PEs to enable it to transport the P2MP
  PW.

3.3.  P2MP PW Construction

  [RFC5332] introduces two approaches to assigning MPLS labels (meaning
  PW labels in the P2MP PW context): Upstream-Assigned [RFC5331] and
  Downstream-Assigned.  However, it is out of scope of this document
  which one should be used in PW construction.  It is left to the
  specification of the solution.

  The following requirements apply to the establishment of P2MP PWs:

  -  PE nodes MUST be configurable with the P2MP PW identifiers and
     ACs.

  -  A discovery mechanism SHOULD allow the Root PE to discover the
     Leaf PEs, or vice versa.






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  -  Solutions SHOULD allow single-sided operation at the Root PE for
     the selection of some AC(s) at the Leaf PE(s) to be attached to
     the PW tree so that the Root PE controls the leaf attachment.

  -  The Root PE SHOULD support a method to be informed about whether a
     Leaf PE has successfully attached to the PW tree.

3.4.  P2MP PW Signaling Requirements

3.4.1.  P2MP PW Identifier

  The P2MP PW MUST be uniquely identified.  This unique P2MP PW
  identifier MUST be used for all signaling procedures related to this
  PW (PW setup, monitoring, etc.).

3.4.2.  PW Type Mismatch

  The Root PE and Leaf PEs of a P2MP PW MUST be configured with the
  same PW type as defined in [RFC4446] for P2P PW.  In case of a type
  mismatch, a PE SHOULD abort attempts to attach the Leaf PE to the
  P2MP PW.

3.4.3.  Interface Parameters Sub-TLV

  Some interface parameters [RFC4446] related to the AC capability have
  been defined according to the PW type and are signaled during the PW
  setup.

  Where applicable, a solution is REQUIRED to ascertain whether the AC
  at the Leaf PE is capable of supporting traffic coming from the AC at
  the Root PE.

  In case of a mismatch, the passive PE (Root or Leaf PE, depending on
  the signaling process) SHOULD support mechanisms to reject attempts
  to attach the Leaf PE to the P2MP PW.

3.4.4.  Leaf Grafting/Pruning

  Once the PW tree is established, the solution MUST allow the addition
  or removal of a Leaf PE, or a subset of leaves to/from the existing
  tree, without any impact on the PW tree (data and control planes) for
  the remaining Leaf PEs.

  The addition or removal of a Leaf PE MUST also allow the P2MP PSN
  tunnel to be updated accordingly.  This may cause the P2MP PSN tunnel
  to add or remove the corresponding Leaf PE.





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3.4.5.  Failure Detection and Reporting

  Since the underlying layer has an end-to-end P2MP topology between
  the Root PE and the Leaf PEs, the failure reporting and processing
  procedures are implemented only on the edge nodes.

  Failure events may cause one or more Leaf PEs to become detached from
  the PW tree.  These events MUST be reported to the Root PE, using
  appropriate out-of-band or in-band Operations, Administration, and
  Maintenance (OAM) messages for monitoring.

  It MUST be possible for the operator to choose the out-of-band or in-
  band monitoring tools or both to monitor the Leaf PE status.  For
  management purposes, the solution SHOULD allow the Root PE to be
  informed of Leaf PEs' failure.

  Based on these failure notifications, solutions MUST allow the Root
  PE to update the remaining leaves of the PW tree.

  -  A solution MUST support an in-band status notification mechanism
     to detect failures: unidirectional point-to-multipoint traffic
     failure.  This MUST be realized by enhancing existing unicast PW
     methods, such as Virtual Circuit Connectivity Verification (VCCV)
     for seamless and familiar operation as defined in [RFC5085].

  -  In case of failure, it MUST correctly report which Leaf PEs are
     affected.  This MUST be realized by enhancing existing PW methods,
     such as LDP Status Notification.  The notification message SHOULD
     include the type of fault (P2MP PW, AC, or PSN tunnel).

  -  A Leaf PE MAY be notified of the status of the Root PE's AC.

  -  A solution MUST support OAM message mapping [RFC6310] at the Root
     PE and Leaf PE if a failure is detected on the source CE.

3.4.6.  Protection and Restoration

  It is assumed that if recovery procedures are required, the P2MP PSN
  tunnel will support standard MPLS-based recovery techniques.  In that
  case, a mechanism SHOULD be implemented to avoid race conditions
  between recovery at the PSN level and recovery at the PW level.

  An alternative protection scheme MAY rely on the PW layer.

  Leaf PEs MAY be protected via a P2MP PW redundancy mechanism.  In the
  example depicted below, a standby P2MP PW is used to protect the
  active P2MP PW.  In that protection scheme, the AC at the Root PE
  MUST serve both P2MP PWs.  In this scenario, the criteria for



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  switching over SHOULD be defined, e.g., failure of one or all leaves
  of the active P2MP PW will trigger switchover of the whole P2MP PW.

                                    CE1
                                     |
        ROOT           active       PE1    standby
                       P2MP PW  .../  \....P2MP PW
                               /           \
                             P2            P3
                            / \           / \
                           /   \         /   \
                          /     \       /     \
        LEAF            PE4    PE5    PE6    PE7
                         |      |      |      |
                         |       \    /       |
                          \        CE2       /
                           \                /
                             ------CE3-----

     Figure 3: Example of P2MP PW Redundancy for Protecting Leaf PEs

  Note that some of the nodes/links in this figure can be physically
  shared; this depends on the service provider policy of network
  redundancy.

  The Root PE MAY be protected via a P2MP PW redundancy mechanism.  In
  the example depicted below, a standby P2MP PW is used to protect the
  active P2MP.  A single AC at the Leaf PE MUST be used to attach the
  CE to the primary and the standby P2MP PW.  The Leaf PE MUST support
  protection mechanisms in order to select the active P2MP PW.

                                    CE1
                                   /  \
                                  |    |
              ROOT     active    PE1  PE2   standby
                       P2MP PW1   |    |    P2MP PW2
                                  |    |
                                  P2  P3
                                 /  \/  \
                                /   /\   \
                               /   /  \   \
                              /   /    \   \
              LEAF            PE4        PE5
                               |          |
                              CE2        CE3

     Figure 4: Example of P2MP PW Redundancy for Protecting Root PEs




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3.4.7.  Scalability

  The solution SHOULD scale at worst linearly for message size, memory
  requirements, and processing requirements, with the number of Leaf
  PEs.

  Increasing the number of P2MP PWs between a Root PE and a given set
  of Leaf PEs SHOULD NOT cause the P router to increase the number of
  entries in its forwarding table by the same or greater proportion.
  Multiplexing P2MP PWs to P2MP PSN tunnels achieves this.

4.  Backward Compatibility

  Solutions MUST be backward compatible with current PW standards.
  Solutions SHOULD utilize existing capability advertisement and
  negotiation procedures for the PEs implementing P2MP PW endpoints.

  The implementation of OAM mechanisms also implies the advertisement
  of PE capabilities to support specific OAM features.  The solution
  MAY allow advertising P2MP PW OAM capabilities.  A solution MUST NOT
  allow a P2MP PW to be established to PEs that do not support P2MP PW
  functionality.  It MUST have a mechanism to report an error for
  incompatible PEs.

  In some cases, upstream traffic is needed from downstream CEs to
  upstream CEs.  The P2MP PW solution SHOULD allow a return path (i.e.,
  from the Leaf PE to the Root PE) that provides upstream connectivity.

  In particular, the same ACs MAY be shared between the downstream and
  upstream directions.  For downstream, a CE receives traffic
  originated by the Root PE over its AC.  For upstream, the CE MAY also
  send traffic destined to the same Root PE over the same AC.

5.  Security Considerations

  The security requirements common to PW are raised in Section 11 of
  [RFC3916].  P2MP PW is a variant of the initial P2P PW definition,
  and those requirements (and the security considerations from
  [RFC3985]) also apply.  The security considerations from [RFC5920]
  and [RFC6941] also apply to the IP/MPLS and MPLS-TP deployment
  scenarios, respectively.

  Some issues specifically due to P2MP topology need to be addressed in
  the definition of the solution:

  -  The solution SHOULD provide means to protect the traffic delivered
     to receivers (Integrity, Confidentiality, Endpoint
     Authentication).



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  -  The solution SHOULD support means to protect the P2MP PW as a
     whole against attacks that would lead to any kind of denial of
     service.

  Specifically, safeguard mechanisms should be considered to avoid any
  negative impact on the whole PW tree when any one receiver or any
  group of receivers is attacked.  Safeguard mechanisms for both the
  data plane and the control plane need to be considered.

6.  References

6.1.  Normative References

  [RFC2119]   Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119, March 1997.

  [RFC3916]   Xiao, X., Ed., McPherson, D., Ed., and P. Pate, Ed.,
              "Requirements for Pseudo-Wire Emulation Edge-to-Edge
              (PWE3)", RFC 3916, September 2004.

  [RFC3985]   Bryant, S., Ed., and P. Pate, Ed., "Pseudo Wire Emulation
              Edge-to-Edge (PWE3) Architecture", RFC 3985, March 2005.

  [RFC4446]   Martini, L., "IANA Allocations for Pseudowire Edge to
              Edge Emulation (PWE3)", BCP 116, RFC 4446, April 2006.

  [RFC5332]   Eckert, T., Rosen, E., Ed., Aggarwal, R., and Y. Rekhter,
              "MPLS Multicast Encapsulations", RFC 5332, August 2008.

  [RFC5659]   Bocci, M. and S. Bryant, "An Architecture for Multi-
              Segment Pseudowire Emulation Edge-to-Edge", RFC 5659,
              October 2009.

  [RFC6310]   Aissaoui, M., Busschbach, P., Martini, L., Morrow, M.,
              Nadeau, T., and Y(J). Stein, "Pseudowire (PW) Operations,
              Administration, and Maintenance (OAM) Message Mapping",
              RFC 6310, July 2011.

6.2.  Informative References

  [RFC4023]   Worster, T., Rekhter, Y., and E. Rosen, Ed.,
              "Encapsulating MPLS in IP or Generic Routing
              Encapsulation (GRE)", RFC 4023, March 2005.

  [RFC4461]   Yasukawa, S., Ed., "Signaling Requirements for Point-to-
              Multipoint Traffic-Engineered MPLS Label Switched Paths
              (LSPs)", RFC 4461, April 2006.




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RFC 7338                  P2MP PW Requirements            September 2014


  [RFC4875]   Aggarwal, R., Ed., Papadimitriou, D., Ed., and S.
              Yasukawa, Ed., "Extensions to Resource Reservation
              Protocol - Traffic Engineering (RSVP-TE) for Point-to-
              Multipoint TE Label Switched Paths (LSPs)", RFC 4875, May
              2007.

  [RFC5085]   Nadeau, T., Ed., and C. Pignataro, Ed., "Pseudowire
              Virtual Circuit Connectivity Verification (VCCV): A
              Control Channel for Pseudowires", RFC 5085, December
              2007.

  [RFC5254]   Bitar, N., Ed., Bocci, M., Ed., and L. Martini, Ed.,
              "Requirements for Multi-Segment Pseudowire Emulation
              Edge-to-Edge (PWE3)", RFC 5254, October 2008.

  [RFC5331]   Aggarwal, R., Rekhter, Y., and E. Rosen, "MPLS Upstream
              Label Assignment and Context-Specific Label Space", RFC
              5331, August 2008.

  [RFC5920]   Fang, L., Ed., "Security Framework for MPLS and GMPLS
              Networks", RFC 5920, July 2010.

  [RFC6388]   Wijnands, IJ., Ed., Minei, I., Ed., Kompella, K., and B.
              Thomas, "Label Distribution Protocol Extensions for
              Point-to-Multipoint and Multipoint-to-Multipoint Label
              Switched Paths", RFC 6388, November 2011.

  [RFC6941]   Fang, L., Ed., Niven-Jenkins, B., Ed., Mansfield, S.,
              Ed., and R. Graveman, Ed., "MPLS Transport Profile
              (MPLS-TP) Security Framework", RFC 6941, April 2013.

  [VPMS-REQS] Kamite, Y., Jounay, F., Niven-Jenkins, B., Brungard, D.,
              and L. Jin, "Framework and Requirements for Virtual
              Private Multicast Service (VPMS)", Work in Progress,
              October 2012.

7.  Acknowledgments

  The authors thank the following people: the authors of [RFC4461]
  since the structure and content of this document were, for some
  sections, largely inspired by [RFC4461]; JL. Le Roux and A. Cauvin
  for the discussions, comments, and support; Adrian Farrel for his
  Routing Area Director review; and IESG reviewers.








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8.  Contributors

  Philippe Niger
  France Telecom
  2, avenue Pierre-Marzin
  22307 Lannion Cedex
  France

  EMail: [email protected]


  Luca Martini
  Cisco Systems, Inc.
  9155 East Nichols Avenue, Suite 400
  Englewood, CO  80112
  US

  EMail: [email protected]


  Lei Wang
  Telenor
  Snaroyveien 30
  Fornebu 1331
  Norway

  EMail: [email protected]


  Rahul Aggarwal
  Juniper Networks
  1194 North Mathilda Ave.
  Sunnyvale, CA  94089
  US

  EMail: [email protected]


  Simon Delord
  Telstra
  380 Flinders Lane
  Melbourne
  Australia

  EMail: [email protected]






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  Martin Vigoureux
  Alcatel-Lucent France
  Route de Villejust
  91620 Nozay
  France

  EMail: [email protected]


  Lizhong Jin
  ZTE Corporation
  889, Bibo Road
  Shanghai, 201203
  China

  EMail: [email protected]



































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RFC 7338                  P2MP PW Requirements            September 2014


Authors' Addresses

  Frederic Jounay (editor)
  Orange CH
  4 rue caudray 1020 Renens
  Switzerland

  EMail: [email protected]


  Yuji Kamite (editor)
  NTT Communications Corporation
  1-1-6 Uchisaiwai-cho, Chiyoda-ku
  Tokyo 100-8019
  Japan

  EMail: [email protected]


  Giles Heron
  Cisco Systems, Inc.
  9 New Square
  Bedfont Lakes
  Feltham
  Middlesex
  TW14 8HA
  United Kingdom

  EMail: [email protected]


  Matthew Bocci
  Alcatel-Lucent Telecom Ltd
  Voyager Place
  Shoppenhangers Road
  Maidenhead
  Berks
  United Kingdom

  EMail: [email protected]











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