Internet Engineering Task Force (IETF)                     K. Cartwright
Request for Comments: 7877                                     V. Bhatia
Category: Standards Track                                            TNS
ISSN: 2070-1721                                                   S. Ali
                                                                NeuStar
                                                            D. Schwartz
                                                               XConnect
                                                            August 2016


            Session Peering Provisioning Framework (SPPF)

Abstract

  This document specifies the data model and the overall structure for
  a framework to provision Session Establishment Data (SED) into
  Session Data Registries and SIP Service Provider (SSP) data stores.
  The framework is called the "Session Peering Provisioning Framework"
  (SPPF).  The provisioned data is typically used by network elements
  for session establishment.

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
  http://www.rfc-editor.org/info/rfc7877.

















Cartwright, et al.           Standards Track                    [Page 1]

RFC 7877                          SSPF                       August 2016


Copyright Notice

  Copyright (c) 2016 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
  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  . . . . . . . . . . . . . . . . . . . . . . . .   3
  2.  Terminology . . . . . . . . . . . . . . . . . . . . . . . . .   6
  3.  Framework High-Level Design . . . . . . . . . . . . . . . . .   7
    3.1.  Framework Data Model  . . . . . . . . . . . . . . . . . .   7
    3.2.  Time Value  . . . . . . . . . . . . . . . . . . . . . . .  10
    3.3.  Extensibility . . . . . . . . . . . . . . . . . . . . . .  10
  4.  Substrate Protocol Requirements . . . . . . . . . . . . . . .  11
    4.1.  Mandatory Substrate . . . . . . . . . . . . . . . . . . .  11
    4.2.  Connection Oriented . . . . . . . . . . . . . . . . . . .  11
    4.3.  Request and Response Model  . . . . . . . . . . . . . . .  11
    4.4.  Connection Lifetime . . . . . . . . . . . . . . . . . . .  11
    4.5.  Authentication  . . . . . . . . . . . . . . . . . . . . .  12
    4.6.  Authorization . . . . . . . . . . . . . . . . . . . . . .  12
    4.7.  Confidentiality and Integrity . . . . . . . . . . . . . .  12
    4.8.  Near Real Time  . . . . . . . . . . . . . . . . . . . . .  12
    4.9.  Request and Response Sizes  . . . . . . . . . . . . . . .  12
    4.10. Request and Response Correlation  . . . . . . . . . . . .  13
    4.11. Request Acknowledgement . . . . . . . . . . . . . . . . .  13
  5.  Base Framework Data Structures and Response Codes . . . . . .  13
    5.1.  Basic Object Type and Organization Identifiers  . . . . .  13
    5.2.  Various Object Key Types  . . . . . . . . . . . . . . . .  14
      5.2.1.  Generic Object Key Type . . . . . . . . . . . . . . .  14
      5.2.2.  Derived Object Key Types  . . . . . . . . . . . . . .  15
    5.3.  Response Message Types  . . . . . . . . . . . . . . . . .  16
  6.  Framework Data Model Objects  . . . . . . . . . . . . . . . .  18
    6.1.  Destination Group . . . . . . . . . . . . . . . . . . . .  18
    6.2.  Public Identifier . . . . . . . . . . . . . . . . . . . .  19
    6.3.  SED Group . . . . . . . . . . . . . . . . . . . . . . . .  25
    6.4.  SED Record  . . . . . . . . . . . . . . . . . . . . . . .  29
    6.5.  SED Group Offer . . . . . . . . . . . . . . . . . . . . .  33
    6.6.  Egress Route  . . . . . . . . . . . . . . . . . . . . . .  35



Cartwright, et al.           Standards Track                    [Page 2]

RFC 7877                          SSPF                       August 2016


  7.  Framework Operations  . . . . . . . . . . . . . . . . . . . .  36
    7.1.  Add Operation . . . . . . . . . . . . . . . . . . . . . .  37
    7.2.  Delete Operation  . . . . . . . . . . . . . . . . . . . .  37
    7.3.  Get Operations  . . . . . . . . . . . . . . . . . . . . .  38
    7.4.  Accept Operations . . . . . . . . . . . . . . . . . . . .  38
    7.5.  Reject Operations . . . . . . . . . . . . . . . . . . . .  39
    7.6.  Get Server Details Operation  . . . . . . . . . . . . . .  39
  8.  XML Considerations  . . . . . . . . . . . . . . . . . . . . .  40
    8.1.  Namespaces  . . . . . . . . . . . . . . . . . . . . . . .  40
    8.2.  Versioning and Character Encoding . . . . . . . . . . . .  40
  9.  Security Considerations . . . . . . . . . . . . . . . . . . .  41
    9.1.  Confidentiality and Authentication  . . . . . . . . . . .  41
    9.2.  Authorization . . . . . . . . . . . . . . . . . . . . . .  41
    9.3.  Denial of Service . . . . . . . . . . . . . . . . . . . .  41
      9.3.1.  DoS Issues Inherited from the Substrate Mechanism . .  42
      9.3.2.  DoS Issues Specific to SPPF . . . . . . . . . . . . .  42
    9.4.  Information Disclosure  . . . . . . . . . . . . . . . . .  43
    9.5.  Non-repudiation . . . . . . . . . . . . . . . . . . . . .  43
    9.6.  Replay Attacks  . . . . . . . . . . . . . . . . . . . . .  43
    9.7.  Compromised or Malicious Intermediary . . . . . . . . . .  44
  10. Internationalization Considerations . . . . . . . . . . . . .  44
  11. IANA Considerations . . . . . . . . . . . . . . . . . . . . .  44
    11.1.  URN Assignments  . . . . . . . . . . . . . . . . . . . .  44
    11.2.  Organization Identifier Namespace Registry . . . . . . .  45
  12. Formal Specification  . . . . . . . . . . . . . . . . . . . .  45
  13. References  . . . . . . . . . . . . . . . . . . . . . . . . .  54
    13.1.  Normative References . . . . . . . . . . . . . . . . . .  54
    13.2.  Informative References . . . . . . . . . . . . . . . . .  55
  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . . . .  57
  Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  57

1.  Introduction

  Service Providers (SPs) and enterprises use routing databases known
  as Registries to make session routing decisions for Voice over IP,
  SMS, and Multimedia Messaging Service (MMS) traffic exchanges.  This
  document is narrowly focused on the provisioning framework for these
  Registries.  This framework prescribes a way for an entity to
  provision session-related data into a Session Peering Provisioning
  Protocol (SPPP) Registry (or "Registry").  The data being provisioned
  can be optionally shared with other participating peering entities.
  The requirements and use cases driving this framework have been
  documented in [RFC6461].

  Three types of provisioning flows have been described in the use case
  document: client to Registry, Registry to local data repository, and
  Registry to Registry.  This document addresses client-to-Registry
  flow enabling the ability to provision Session Establishment Data



Cartwright, et al.           Standards Track                    [Page 3]

RFC 7877                          SSPF                       August 2016


  (SED).  The framework that supports the flow of messages to
  facilitate client-to-Registry provisioning is referred to as the
  "Session Peering Provisioning Framework" (SPPF).

  The roles of the "client" and the "server" only apply to the
  connection, and those roles are not related in any way to the type of
  entity that participates in a protocol exchange.  For example, a
  Registry might also include a "client" when such a Registry initiates
  a connection (for example, for data distribution to an SSP).

  *--------*               *------------*               *------------*
  |        | (1) Client   |             | (3) Registry  |            |
  | Client | ------------> |  Registry  |<------------->|  Registry  |
  |        |   to Registry |            |  to Registry  |            |
  *--------*               *------------*               *------------*
                                /  \                          \
                               /    \                          \
                              /      \                          \
                             /        \                          v
                            /          \                         ...
                           /            \
                          / (2) Distrib  \
                         / Registry data  \
                        /  to local data   \
                       V      store         V
                      +----------+       +----------+
                      |Local Data|       |Local Data|
                      |Repository|       |Repository|
                      +----------+       +----------+

               Figure 1: Three Registry Provisioning Flows

  A "terminating" SSP provisions SED into the Registry to be
  selectively shared with other peer SSPs.

  SED is typically used by various downstream SIP-signaling systems to
  route a call to the next hop associated with the called domain.
  These systems typically use a local data store ("Local Data
  Repository") as their source of session routing information.  More
  specifically, the SED is the set of parameters that the outgoing
  Signaling Path Border Elements (SBEs) need to initiate the session.
  See [RFC5486] for more details.

  A Registry may distribute the provisioned data into local data
  repositories or may additionally offer a central query-resolution
  service (not shown in the above figure) for query purposes.





Cartwright, et al.           Standards Track                    [Page 4]

RFC 7877                          SSPF                       August 2016


  A key requirement for the SPPF is to be able to accommodate two basic
  deployment scenarios:

  1.  A resolution system returns a Lookup Function (LUF) that
      identifies the target domain to assist in call routing (as
      described in Section 4.3.3 of [RFC5486]).  In this case, the
      querying entity may use other means to perform the Location
      Routing Function (LRF), which in turn helps determine the actual
      location of the Signaling Function in that domain.

  2.  A resolution system returns an LRF that comprises the location
      (address) of the Signaling Function in the target domain (as
      described in [RFC5486]).

  In terms of framework design, SPPF is agnostic to the substrate
  protocol.  This document includes the specification of the data model
  and identifies, but does not specify, the means to enable protocol
  operations within a request and response structure.  That aspect of
  the specification has been delegated to the "protocol" specification
  for the framework.  To encourage interoperability, the framework
  supports extensibility aspects.

  In this document, an XML Schema is used to describe the building
  blocks of the SPPF and to express the data types, semantic
  relationships between the various data types, and various constraints
  as a binding construct.  However, a "protocol" specification is free
  to choose any data representation format as long as it meets the
  requirements laid out in the SPPF XML Schema Definition (XSD).  As an
  example, XML and JSON are two widely used data representation
  formats.

  This document is organized as follows:

  o  Section 2 provides the terminology

  o  Section 3 provides an overview of SPPF, including functional
     entities and a data model

  o  Section 4 specifies requirements for SPPF substrate protocols

  o  Section 5 describes the base framework data structures, the
     generic response types that MUST be supported by a conforming
     substrate "protocol" specification, and the basic object type from
     which most first-class objects extend

  o  Section 6 provides a detailed description of the data model object
     specifications




Cartwright, et al.           Standards Track                    [Page 5]

RFC 7877                          SSPF                       August 2016


  o  Section 7 describes the operations that are supported by the data
     model

  o  Section 8 defines XML considerations XML parsers must meet to
     conform to this specification

  o  Sections 9 - 11 discuss security, internationalization, and IANA
     considerations, respectively

  o  Section 12 normatively defines the SPPF using its XSD.

2.  Terminology

  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
  [RFC2119].

  This document reuses terms from [RFC3261], [RFC5486], use cases and
  requirements documented in [RFC6461], and the ENUM Validation
  Architecture [RFC4725].

  This document defines the following additional terms:

  SPPF:   Session Peering Provisioning Framework, which is the
     framework used by a substrate protocol to provision data into a
     Registry (see arrow labeled "1" in Figure 1 of [RFC6461]).  It is
     the primary scope of this document.

  Client:   In the context of SPPF, this is an application that
     initiates a provisioning request.  It is sometimes referred to as
     a "Registry client".

  Server:   In the context of SPPF, this is an application that
     receives a provisioning request and responds accordingly.

  Registry:   The Registry operates a master database of SED for one or
     more Registrants.

  Registrant:   The definition of a Registrant is based on [RFC4725].
     It is the end user, person, or organization that is the "holder"
     of the SED being provisioned into the Registry by a Registrar.
     For example, in [RFC6461], a Registrant is pictured as an SP in
     Figure 2.

     Within the confines of a Registry, a Registrant is uniquely
     identified by the "rant" element.




Cartwright, et al.           Standards Track                    [Page 6]

RFC 7877                          SSPF                       August 2016


  Registrar:   The definition of a Registrar is based on [RFC4725].  It
     is an entity that performs provisioning operations on behalf of a
     Registrant by interacting with the Registry via SPPF operations.
     In other words, the Registrar is the SPPF client.  The Registrar
     and Registrant roles are logically separate to allow, but not
     require, a single Registrar to perform provisioning operations on
     behalf of more than one Registrant.

  Peering Organization:   A peering organization is an entity to which
     a Registrant's SED Groups are made visible using the operations of
     SPPF.

3.  Framework High-Level Design

  This section introduces the structure of the data model and provides
  the information framework for the SPPF.  The data model is defined
  along with all the objects manipulated by a conforming substrate
  protocol and their relationships.

3.1.  Framework Data Model

  The data model illustrated and described in Figure 2 defines the
  logical objects and the relationships between these objects supported
  by SPPF.  SPPF defines protocol operations through which an SPPF
  client populates a Registry with these logical objects.  SPPF clients
  belonging to different Registrars may provision data into the
  Registry using a conforming substrate protocol that implements these
  operations

  The logical structure presented below is consistent with the
  terminology and requirements defined in [RFC6461].




















Cartwright, et al.           Standards Track                    [Page 7]

RFC 7877                          SSPF                       August 2016


      +-------------+                        +-----------------+
      | All object  |                        |Egress Route:    |
      | types       |                   0..n | rant,           |
      +-------------+                     +--| egrRteName,     |
            |0..n                        /   | pref,           |
            |                           /    | regxRewriteRule,|
            |2                         /     | ingrSedGrp,     |
  +----------------------+            /      | svcs            |
  |Organization:         |           /       +-----------------+
  | orgId                |          /
  +----------------------+         /
         |0..n                    /
         |                       /        ("rant" = Registrant)
         |A SED Group is        /
         |associated with      /
         |zero or more        /              +---[abstract]----+
         |peering            /               | SED Record:     |
         |organizations     /                |  rant,          |
         |                 /                 |  sedName,       |0..n
         |0..n            /                  |  sedFunction,   |------|
  +--------+--------------+0..n          0..n|  isInSvc,       |      |
  |SED Group:             |------------------|  ttl            |      |
  |  rant,                |                  +-----------------+      |
  |  sedGrpName,          |                      ^ Various types      |
  |  isInSvc,             |                      | of SED Records     |
  |  sedRecRef,           |                      |                    |
  |  peeringOrg,          |                +-----+------------+       |
  |  sourceIdent,         |                |        |         |       |
  |  priority,            |             +----+  +-------+  +----+     |
  |  dgName               |             | URI|  | NAPTR |  | NS |     |
  +-----------------------+             +----+  +-------+  +----+     |
         |0..n                                                        |
         |                                 +-----[abstract]------+    |
         |0..n                             |Public Identifier:   |    |
     +----------------------+0..n      0..n|  rant,              |    |
     | Dest Group:          |--------------|  publicIdentifier,  |    |
     |   rant,              |              |  dgName             |    |
     |   dgName             |              |                     |    |
     +----------------------+              +---------------------+    |
                                                    ^ Various types   |
                +---------+-------+------+----------+ of Public       |
                |         |       |      |          | Identifiers     |
             +------+  +-----+  +-----+ +-----+  +------+             |
             |  URI |  | TNP |  | TNR | | RN  |  |  TN  |-------------|
             +------+  +-----+  +-----+ +-----+  +------+  0..n

                     Figure 2: Framework Data Model




Cartwright, et al.           Standards Track                    [Page 8]

RFC 7877                          SSPF                       August 2016


  The objects and attributes that comprise the data model can be
  described as follows (objects listed from the bottom up):

  o  Public Identifier:
     From a broad perspective, a Public Identifier is a well-known
     attribute that is used as the key to perform resolution lookups.
     Within the context of SPPF, a Public Identifier object can be a
     Telephone Number (TN), a range of TNs, a Public Switched Telephone
     Network (PSTN) Routing Number (RN), a TN prefix, or a URI.

     An SPPF Public Identifier may be a member of zero or more
     Destination Groups to create logical groupings of Public
     Identifiers that share a common set of SED (e.g., routes).

     A TN Public Identifier may optionally be associated with zero or
     more individual SED Records.  This ability for a Public Identifier
     to be directly associated with a SED Record, as opposed to forcing
     membership in one or more Destination Groups, supports use cases
     where the SED Record contains data specifically tailored to an
     individual TN Public Identifier.

  o  Destination Group:
     A named logical grouping of zero or more Public Identifiers that
     can be associated with one or more SED Groups for the purpose of
     facilitating the management of their common SED.

  o  SED Group:
     A SED Group contains a set of SED Record references, a set of
     Destination Group references, and a set of peering organization
     identifiers.  This is used to establish a three-part relationship
     between a set of Public Identifiers, the SED shared across these
     Public Identifiers, and the list of peering organizations whose
     query responses from the resolution system may include the SED
     contained in a given SED Group.  In addition, the sourceIdent
     element within a SED Group, in concert with the set of peering
     organization identifiers, enables fine-grained source-based
     routing.  For further details about the SED Group and source-based
     routing, refer to the definitions and descriptions in Section 6.1.

  o  SED Record:
     A SED Record contains the data that a resolution system returns in
     response to a successful query for a Public Identifier.  SED
     Records are generally associated with a SED Group when the SED
     within is not specific to a Public Identifier.

     To support the use cases defined in [RFC6461], the SPPF defines
     three types of SED Records: URIType, NAPTRType, and NSType.  These
     SED Records extend the abstract type SedRecType and inherit the



Cartwright, et al.           Standards Track                    [Page 9]

RFC 7877                          SSPF                       August 2016


     common attribute "priority" that is meant for setting precedence
     across the SED Records defined within a SED Group in a protocol-
     agnostic fashion.

  o  Egress Route:
     In a high-availability environment, the originating SSP likely has
     more than one egress path to the ingress SBE of the target SSP.
     The Egress Route allows the originating SSP to choose a specific
     egress SBE to be associated with the target ingress SBE.  The
     "svcs" element specifies ENUM services (e.g., E2U+pstn:sip+sip)
     that are used to identify the SED Records associated with the SED
     Group that will be modified by the originating SSP.

  o  Organization:
     An Organization is an entity that may fulfill any combination of
     three roles: Registrant, Registrar, and peering organization.  All
     objects in SPPF are associated with two organization identifiers
     to identify each object's Registrant and Registrar.  A SED Group
     object is also associated with a set of zero or more organization
     identifiers that identify the peering organization(s) whose
     resolution query responses may include the SED defined in the SED
     Records within that SED Group.  A peering organization is an
     entity with which the Registrant intends to share the SED data.

3.2.  Time Value

  Some request and response messages in SPPF include a time value or
  values defined as type xs:dateTime, a built-in W3C XML Schema
  Datatype.  Use of an unqualified local time value is disallowed as it
  can lead to interoperability issues.  The value of a time attribute
  MUST be expressed in Coordinated Universal Time (UTC) format without
  the time-zone digits.

  "2010-05-30T09:30:10Z" is an example of an acceptable time value for
  use in SPPF messages.  "2010-05-30T06:30:10+3:00" is a valid UTC time
  but is not acceptable for use in SPPF messages.

3.3.  Extensibility

  The framework contains various points of extensibility in the form of
  the "ext" elements.  Extensions used beyond the scope of private SPPF
  installations need to be documented in an RFC, and the first such
  extension is expected to define an IANA registry, holding a list of
  documented extensions.







Cartwright, et al.           Standards Track                   [Page 10]

RFC 7877                          SSPF                       August 2016


4.  Substrate Protocol Requirements

  This section provides requirements for substrate protocols suitable
  to carry SPPF.  More specifically, this section specifies the
  services, features, and assumptions that SPPF delegates to the chosen
  substrate and envelope technologies.

4.1.  Mandatory Substrate

  None of the existing transport protocols carried directly over IP,
  appearing as "Protocol" in the IPv4 headers or "Next Header" in the
  IPv6 headers, meet the requirements listed in this section to carry
  SPPF.

  Therefore, one choice to carry SPPF has been provided in "Session
  Peering Provisioning (SPP) Protocol over SOAP" [RFC7878], using SOAP
  as the substrate.  To encourage interoperability, the SPPF server
  MUST provide support for this protocol.  With time, it is possible
  that other choices may surface that comply with the requirements
  discussed above.

4.2.  Connection Oriented

  The SPPF follows a model where a client establishes a connection to a
  server in order to further exchange SPPF messages over such a point-
  to-point connection.  Therefore, a substrate protocol for SPPF will
  be connection oriented.

4.3.  Request and Response Model

  Provisioning operations in SPPF follow the request-response model,
  where a client sends a request message to initiate a transaction and
  the server sends a response.  Multiple subsequent request-response
  exchanges MAY be performed over a single persistent connection.

  Therefore, a substrate protocol for SPPF will follow the request-
  response model by ensuring a response is sent to the request
  initiator.

4.4.  Connection Lifetime

  Some use cases involve provisioning a single request to a network
  element.  Connections supporting such provisioning requests might be
  short-lived, and may be established only on demand, for the duration
  of a few seconds.  Other use cases involve provisioning either a
  large dataset or a constant stream of small updates, both of which
  would likely require long-lived connections, spanning multiple hours
  or even days.



Cartwright, et al.           Standards Track                   [Page 11]

RFC 7877                          SSPF                       August 2016


  Therefore, a protocol suitable for SPPF SHOULD be able to support
  both short-lived and long-lived connections.

4.5.  Authentication

  All SPPF objects are associated with a Registrant identifier.  An
  SPPF client provisions SPPF objects on behalf of Registrants.  An
  authenticated SPP client is a Registrar.  Therefore, the SPPF
  substrate protocol MUST provide means for an SPPF server to
  authenticate an SPPF client.

4.6.  Authorization

  After successful authentication of the SPPF client as a Registrar,
  the Registry performs authorization checks to determine if the
  Registrar is authorized to act on behalf of the Registrant whose
  identifier is included in the SPPF request.  Refer to Section 9 for
  further guidance.

4.7.  Confidentiality and Integrity

  SPPF objects that the Registry manages can be private in nature.
  Therefore, the substrate protocol MUST provide means for data
  integrity protection.

  If the data is compromised in-flight between the SPPF client and
  Registry, it will seriously affect the stability and integrity of the
  system.  Therefore, the substrate protocol MUST provide means for
  data integrity protection.

4.8.  Near Real Time

  Many use cases require responses in near real time from the server
  (in the range of a few multiples of round-trip time between the
  server and client).  Therefore, a Data for Reachability of
  Inter-/Intra-NetworK SIP (DRINKS) substrate protocol MUST support
  near real-time responses to requests submitted by the client.

4.9.  Request and Response Sizes

  Use of SPPF may involve simple updates that may consist of a small
  number of bytes, such as the update of a single Public Identifier.
  Other provisioning operations may constitute a large dataset, as in
  adding millions of records to a Registry.  As a result, a suitable
  substrate protocol for SPPF SHOULD accommodate datasets of various
  sizes.





Cartwright, et al.           Standards Track                   [Page 12]

RFC 7877                          SSPF                       August 2016


4.10.  Request and Response Correlation

  A substrate protocol suitable for SPPF MUST allow responses to be
  correlated with requests.

4.11.  Request Acknowledgement

  Data transported in the SPPF is likely crucial for the operation of
  the communication network that is being provisioned.  An SPPF client
  responsible for provisioning SED to the Registry has a need to know
  if the submitted requests have been processed correctly.

  Failed transactions can lead to situations where a subset of Public
  Identifiers or even SSPs might not be reachable or the provisioning
  state of the network is inconsistent.

  Therefore, a substrate protocol for SPPF MUST provide a response for
  each request, so that a client can identify whether a request
  succeeded or failed.

5.  Base Framework Data Structures and Response Codes

  SPPF contains some common data structures for most of the supported
  object types.  This section describes these common data structures.

5.1.  Basic Object Type and Organization Identifiers

  All first-class objects extend the type BasicObjType.  It consists of
  the Registrant organization, the Registrar organization, the date and
  time of object creation, and the last date and time the object was
  modified.  The Registry MUST store the date and time of the object
  creation and modification, if applicable, for all Get operations (see
  Section 7).  If the client passed in either date or time values, the
  Registry MUST ignore it.  The Registrar performs the SPPF operations
  on behalf of the Registrant, the organization that owns the object.

  <complexType name="BasicObjType" abstract="true">
   <sequence>
    <element name="rant" type="sppfb:OrgIdType"/>
    <element name="rar" type="sppfb:OrgIdType"/>
    <element name="cDate" type="dateTime" minOccurs="0"/>
    <element name="mDate" type="dateTime" minOccurs="0"/>
    <element name="ext" type="sppfb:ExtAnyType" minOccurs="0"/>
   </sequence>
  </complexType>






Cartwright, et al.           Standards Track                   [Page 13]

RFC 7877                          SSPF                       August 2016


  The identifiers used for Registrants (rant) and Registrars (rar) are
  instances of OrgIdType.  The OrgIdType is defined as a string and all
  OrgIdType instances MUST follow the textual convention:
  "namespace:value" (for example, "iana-en:32473").  Specifically:

  Strings used as OrgIdType Namespace identifiers MUST conform to the
  following syntax in the Augmented Backus-Naur Form (ABNF) [RFC5234].

        namespace = ALPHA *(ALPHA/DIGIT/"-")

  See Section 11 for the corresponding IANA registry definition.

5.2.  Various Object Key Types

  The SPPF data model contains various object relationships.  In some
  cases, these object relationships are established by embedding the
  unique identity of the related object inside the relating object.
  Note that an object's unique identity is required to Delete or Get
  the details of an object.  The following subsections normatively
  define the various object keys in SPPF and the attributes of those
  keys.

  "Name" attributes that are used as components of object key types
  MUST be compared using the toCasefold() function, as specified in
  Section 3.13 of [Unicode6.1] (or a newer version of Unicode).  This
  function performs case-insensitive comparisons.

5.2.1.  Generic Object Key Type

  Most objects in SPPF are uniquely identified by an object key that
  has the object's name, type, and Registrant's organization ID as
  attributes.  The abstract type called ObjKeyType is where this unique
  identity is housed.  Any concrete representation of the ObjKeyType
  MUST contain the following:

     Object Name: The name of the object.

     Registrant ID: The unique organization ID that identifies the
     Registrant.

     Type: The value that represents the type of SPPF object.  This is
     required as different types of objects in SPPF, that belong to the
     same Registrant, can have the same name.








Cartwright, et al.           Standards Track                   [Page 14]

RFC 7877                          SSPF                       August 2016


  The structure of abstract ObjKeyType is as follows:

  <complexType name="ObjKeyType" abstract="true">
   <annotation>
    <documentation>
    ---- Generic type that represents the
         key for various objects in SPPF. ----
    </documentation>
   </annotation>
  </complexType>

5.2.2.  Derived Object Key Types

  The SPPF data model contains certain objects that are uniquely
  identified by attributes, different from or in addition to the
  attributes in the generic object key described in the previous
  section.  Object keys of this kind are derived from the abstract
  ObjKeyType and defined in their own abstract key types.  Because
  these object key types are abstract, they MUST be specified in a
  concrete form in any SPPF-conforming substrate "protocol"
  specification.  These are used in Delete and Get operations and may
  also be used in Accept and Reject operations.

  Following are the derived object keys in an SPPF data model:

  o  SedGrpOfferKeyType: This uniquely identifies a SED Group object
     offer.  This key type extends from ObjKeyType and MUST also have
     the organization ID of the Registrant to whom the object is being
     offered as one of its attributes.  In addition to the Delete and
     Get operations, these key types are used in Accept and Reject
     operations on a SED Group Offer object.  The structure of abstract
     SedGrpOfferKeyType is as follows:

  <complexType name="SedGrpOfferKeyType"
  abstract="true">
      <complexContent>
          <extension base="sppfb:ObjKeyType">
              <annotation>
      <documentation>
      ---- Generic type that represents
           the key for an object offer. ----
      </documentation>
     </annotation>
    </extension>
   </complexContent>
  </complexType>





Cartwright, et al.           Standards Track                   [Page 15]

RFC 7877                          SSPF                       August 2016


     A SED Group Offer object MUST use SedGrpOfferKeyType.  Refer to
     Section 6.5 for a description of the SED Group Offer object.

  o  PubIdKeyType: This uniquely identifies a Public Identity object.
     This key type extends from the abstract ObjKeyType.  Any concrete
     definition of PubIdKeyType MUST contain the elements that identify
     the value and type of Public Identity and also contain the
     organization ID of the Registrant that is the owner of the Public
     Identity object.  A Public Identity object in SPPF is uniquely
     identified by the Registrant's organization ID, the value of the
     Public Identity, and the type of the Public Identity object.
     Consequently, any concrete representation of the PubIdKeyType MUST
     contain the following attributes:

     *  Registrant ID: The unique organization ID that identifies the
        Registrant.

     *  Value: The value of the Public Identity.

     *  Type: The type of the Public Identity object.

     The PubIdKeyType is used in Delete and Get operations on a Public
     Identifier object.

  o  The structure of abstract PubIdKeyType is as follows:

  <complexType name="PubIdKeyType" abstract="true">
   <complexContent>
    <extension base="sppfb:ObjKeyType">
     <annotation>
      <documentation>
      ---- Generic type that represents the key for a Pub ID. ----
      </documentation>
     </annotation>
    </extension>
   </complexContent>
  </complexType>

  A Public Identity object MUST use attributes of PubIdKeyType for its
  unique identification.  Refer to Section 6 for a description of a
  Public Identity object.

5.3.  Response Message Types

  The following table contains the list of response types that MUST be
  defined for a substrate protocol used to carry SPPF.  An SPPF server
  MUST implement all of the following at minimum.




Cartwright, et al.           Standards Track                   [Page 16]

RFC 7877                          SSPF                       August 2016


  +---------------------+---------------------------------------------+
  | Response Type       | Description                                 |
  +---------------------+---------------------------------------------+
  | Request succeeded   | A given request succeeded.                  |
  | Request syntax      | The syntax of a given request was found to  |
  | invalid             | be invalid.                                 |
  | Request too large   | The count of entities in the request is     |
  |                     | larger than the server is willing or able   |
  |                     | to process.                                 |
  | Version not         | The server does not support the version of  |
  | supported           | the SPPF protocol specified in the request. |
  | Command invalid     | The operation and/or command being          |
  |                     | requested by the client is invalid and/or   |
  |                     | not supported by the server.                |
  | System temporarily  | The SPPF server is temporarily not          |
  | unavailable         | available to serve the client request.      |
  | Unexpected internal | The SPPF server encountered an unexpected   |
  | system or server    | error that prevented the server from        |
  | error               | fulfilling the request.                     |
  | Attribute value     | The SPPF server encountered an attribute or |
  | invalid             | property in the request that had an         |
  |                     | invalid/bad value.  Optionally, the         |
  |                     | specification MAY provide a way to indicate |
  |                     | the Attribute Name and the Attribute Value  |
  |                     | to identify the object that was found to be |
  |                     | invalid.                                    |
  | Object does not     | An object present in the request does not   |
  | exist               | exist on the SPPF server. Optionally, the   |
  |                     | specification MAY provide a way to indicate |
  |                     | the Attribute Name and the Attribute Value  |
  |                     | that identifies the nonexistent object.     |
  | Object status or    | The operation requested on an object        |
  | ownership does not  | present in the request cannot be performed  |
  | allow for operation | because the object is in a status that does |
  |                     | not allow said operation, or the user       |
  |                     | requesting the operation is not authorized  |
  |                     | to perform said operation on the object.    |
  |                     | Optionally, the specification MAY provide a |
  |                     | way to indicate the Attribute Name and the  |
  |                     | Attribute Value that identifies the object. |
  +---------------------+---------------------------------------------+

                         Table 1: Response Types








Cartwright, et al.           Standards Track                   [Page 17]

RFC 7877                          SSPF                       August 2016


  When the response messages are "parameterized" with the Attribute
  Name and Attribute Value, then the use of these parameters MUST
  adhere to the following rules:

  o  Any value provided for the Attribute Name parameter MUST be an
     exact XSD element name of the protocol data element to which the
     response message is referring.  For example, valid values for
     "attribute name" are "dgName", "sedGrpName", "sedRec", etc.

  o  The value for Attribute Value MUST be the value of the data
     element to which the preceding Attribute Name refers.

  o  Response type "Attribute value invalid" MUST be used whenever an
     element value does not adhere to data validation rules.

  o  Response types "Attribute value invalid" and "Object does not
     exist" MUST NOT be used interchangeably.  Response type "Object
     does not exist" MUST be returned by an Update/Del/Accept/Reject
     operation when the data element(s) used to uniquely identify a
     preexisting object does not exist.  If the data elements used to
     uniquely identify an object are malformed, then response type
     "Attribute value invalid" MUST be returned.

6.  Framework Data Model Objects

  This section provides a description of the specification of each
  supported data model object (the nouns) and identifies the commands
  (the verbs) that MUST be supported for each data model object.
  However, the specification of the data structures necessary to
  support each command is delegated to an SPPF-conforming substrate
  "protocol" specification.

6.1.  Destination Group

  A Destination Group represents a logical grouping of Public
  Identifiers with common SED.  The substrate protocol MUST support the
  ability to Add, Get, and Delete Destination Groups (refer to
  Section 7 for a generic description of various operations).

  A Destination Group object MUST be uniquely identified by attributes
  as defined in the description of "ObjKeyType" in "Generic Object Key
  Type" (Section 5.2.1 of this document).









Cartwright, et al.           Standards Track                   [Page 18]

RFC 7877                          SSPF                       August 2016


  The DestGrpType object structure is defined as follows:

  <complexType name="DestGrpType">
   <complexContent>
    <extension base="sppfb:BasicObjType">
     <sequence>
      <element name="dgName" type="sppfb:ObjNameType"/>
     </sequence>
    </extension>
   </complexContent>
  </complexType>

  The DestGrpType object is composed of the following elements:

  o  base: All first-class objects extend BasicObjType (see
     Section 5.1).

  o  dgName: The character string that contains the name of the
     Destination Group.

  o  ext: Point of extensibility described in Section 3.3.

6.2.  Public Identifier

  A Public Identifier is the search key used for locating the SED.  In
  many cases, a Public Identifier is attributed to the end user who has
  a retail relationship with the SP or Registrant organization.  SPPF
  supports the notion of the carrier-of-record as defined in [RFC5067].
  Therefore, the Registrant under which the Public Identifier is being
  created can optionally claim to be a carrier-of-record.

  SPPF identifies three types of Public Identifiers: TNs, RNs, and
  URIs.  SPPF provides structures to manage a single TN, a contiguous
  range of TNs, and a TN prefix.  The substrate protocol MUST support
  the ability to Add, Get, and Delete Public Identifiers (refer to
  Section 7 for a generic description of various operations).

  A Public Identity object MUST be uniquely identified by attributes as
  defined in the description of "PubIdKeyType" in Section 5.2.2.












Cartwright, et al.           Standards Track                   [Page 19]

RFC 7877                          SSPF                       August 2016


  The abstract XSD type PubIdType is a generalization for the concrete
  Public Identifier schema types.  The PubIdType element "dgName"
  represents the name of a Destination Group of which a given Public
  Identifier may be a member.  Note that this element may be present
  multiple times so that a given Public Identifier may be a member of
  multiple Destination Groups.  The PubIdType object structure is
  defined as follows:

  <complexType name="PubIdType" abstract="true">
   <complexContent>
    <extension base="sppfb:BasicObjType">
     <sequence>
      <element name="dgName" type="sppfb:ObjNameType"
               minOccurs="0" maxOccurs="unbounded"/>
     </sequence>
    </extension>
   </complexContent>
  </complexType>

  A Public Identifier may be a member of zero or more Destination
  Groups.  When a Public Identifier is a member of a Destination Group,
  it is intended to be associated with SED through the SED Group(s)
  that is associated with the Destination Group.  When a Public
  Identifier is not member of any Destination Group, it is intended to
  be associated with SED through the SED Records that are directly
  associated with the Public Identifier.

























Cartwright, et al.           Standards Track                   [Page 20]

RFC 7877                          SSPF                       August 2016


  A TN is provisioned using the TNType, an extension of PubIdType.
  Each TNType object is uniquely identified by the combination of its
  value contained within the <tn> element and its Registrant ID.
  TNType is defined as follows:

  <complexType name="TNType">
   <complexContent>
    <extension base="sppfb:PubIdType">
     <sequence>
      <element name="tn" type="sppfb:NumberValType"/>
      <element name="corInfo" type="sppfb:CORInfoType" minOccurs="0"/>
      <element name="sedRecRef" type="sppfb:SedRecRefType"
               minOccurs="0" maxOccurs="unbounded"/>
     </sequence>
    </extension>
   </complexContent>
  </complexType>

  <complexType name="CORInfoType">
   <sequence>
     <element name="corClaim" type="boolean" default="true"/>
     <element name="cor" type="boolean" default="false" minOccurs="0"/>
     <element name="corDate" type="dateTime" minOccurs="0"/>
   </sequence>
  </complexType>

  <simpleType name="NumberValType">
   <restriction base="token">
    <maxLength value="20"/>
    <pattern value="\+?\d\d*"/>
   </restriction>
  </simpleType>

  TNType consists of the following attributes:

  o  tn: Telephone number to be added to the Registry.

  o  sedRecRef: Optional reference to SED Records that are directly
     associated with the TN Public Identifier.  Following the SPPF data
     model, the SED Record could be a protocol-agnostic URIType or
     another type.

  o  corInfo: corInfo is an optional parameter of type CORInfoType that
     allows the Registrant organization to set forth a claim to be the
     carrier-of-record (see [RFC5067]).  This is done by setting the
     value of the <corClaim> element of the CORInfoType object
     structure to "true".  The other two parameters of the CORInfoType,
     <cor> and <corDate>, are set by the Registry to describe the



Cartwright, et al.           Standards Track                   [Page 21]

RFC 7877                          SSPF                       August 2016


     outcome of the carrier-of-record claim by the Registrant.  In
     general, inclusion of the <corInfo> parameter is useful if the
     Registry has the authority information, such as the number
     portability data, etc., in order to qualify whether the Registrant
     claim can be satisfied.  If the carrier-of-record claim disagrees
     with the authority data in the Registry, whether or not a TN Add
     operation fails is a matter of policy and is beyond the scope of
     this document.

  An RN is provisioned using the RNType, an extension of PubIDType.
  The Registrant organization can add the RN and associate it with the
  appropriate Destination Group(s) to share the route information.
  This allows SSPs to use the RN search key to derive the Ingress
  Routes for session establishment at the runtime resolution process
  (see [RFC6116]).  Each RNType object is uniquely identified by the
  combination of its value inside the <rn> element and its Registrant
  ID.  RNType is defined as follows:

  <complexType name="RNType">
   <complexContent>
    <extension base="sppfb:PubIdType">
     <sequence>
      <element name="rn" type="sppfb:NumberValType"/>
      <element name="corInfo" type="sppfb:CORInfoType" minOccurs="0"/>
     </sequence>
    </extension>
   </complexContent>
  </complexType>

  RNType has the following attributes:

  o  rn: The RN used as the search key.

  o  corInfo: corInfo is an optional parameter of type CORInfoType that
     allows the Registrant organization to set forth a claim to be the
     carrier-of-record (see [RFC5067]).

  TNRType structure is used to provision a contiguous range of TNs.
  The object definition requires a starting TN and an ending TN that
  together define the span of the TN range, including the starting and
  ending TN.  Use of TNRType is particularly useful when expressing a
  TN range that does not include all the TNs within a TN block or
  prefix.  The TNRType definition accommodates the open number plan as
  well such that the TNs that fall in the range between the start and
  end TN may include TNs with different length variance.  Whether the
  Registry can accommodate the open number plan semantics is a matter
  of policy and is beyond the scope of this document.  Each TNRType
  object is uniquely identified by the combination of its value that,



Cartwright, et al.           Standards Track                   [Page 22]

RFC 7877                          SSPF                       August 2016


  in turn, is a combination of the <startTn> and <endTn> elements and
  its Registrant ID.  The TNRType object structure definition is as
  follows:

  <complexType name="TNRType">
   <complexContent>
    <extension base="sppfb:PubIdType">
     <sequence>
      <element name="range" type="sppfb:NumberRangeType"/>
      <element name="corInfo" type="sppfb:CORInfoType" minOccurs="0"/>
     </sequence>
    </extension>
   </complexContent>
  </complexType>

  <complexType name="NumberRangeType">
   <sequence>
    <element name="startTn" type="sppfb:NumberValType"/>
    <element name="endTn" type="sppfb:NumberValType"/>
   </sequence>
  </complexType>

  TNRType has the following attributes:

  o  startTn: The starting TN in the TN range.

  o  endTn: The last TN in the TN range.

  o  corInfo: corInfo is an optional parameter of type CORInfoType that
     allows the Registrant organization to set forth a claim to be the
     carrier-of-record (see [RFC5067]).




















Cartwright, et al.           Standards Track                   [Page 23]

RFC 7877                          SSPF                       August 2016


  In some cases, it is useful to describe a set of TNs with the help of
  the first few digits of the TN, also referred to as the TN prefix or
  a block.  A given TN prefix may include TNs with different length
  variance in support of the open number plan.  Once again, whether the
  Registry supports the open number plan semantics is a matter of
  policy, and it is beyond the scope of this document.  The TNPType
  data structure is used to provision a TN prefix.  Each TNPType object
  is uniquely identified by the combination of its value in the
  <tnPrefix> element and its Registrant ID.  TNPType is defined as
  follows:

  <complexType name="TNPType">
   <complexContent>
    <extension base="sppfb:PubIdType">
     <sequence>
      <element name="tnPrefix" type="sppfb:NumberValType"/>
      <element name="corInfo" type="sppfb:CORInfoType" minOccurs="0"/>
     </sequence>
    </extension>
   </complexContent>
  </complexType>

  TNPType consists of the following attributes:

  o  tnPrefix: The TN prefix.

  o  corInfo: corInfo is an optional parameter of type CORInfoType that
     allows the Registrant organization to set forth a claim to be the
     carrier-of-record (see [RFC5067]).

  In some cases, a Public Identifier may be a URI, such as an email
  address.  The URIPubIdType object is comprised of the data element
  necessary to house such Public Identifiers.  Each URIPubIdType object
  is uniquely identified by the combination of its value in the <uri>
  element and its Registrant ID.  URIPubIdType is defined as follows:

  <complexType name="URIPubIdType">
   <complexContent>
    <extension base="sppfb:PubIdType">
     <sequence>
      <element name="uri" type="anyURI"/>
      <element name="ext" type="sppfb:ExtAnyType" minOccurs="0"/>
     </sequence>
    </extension>
   </complexContent>
  </complexType>





Cartwright, et al.           Standards Track                   [Page 24]

RFC 7877                          SSPF                       August 2016


  URIPubIdType consists of the following attributes:

  o  uri: The value that acts as the Public Identifier.

  o  ext: Point of extensibility described in Section 3.3.

6.3.  SED Group

  SED Group is a grouping of one or more Destination Groups, the common
  SED Records, and the list of peer organizations with access to the
  SED Records associated with a given SED Group.  It is this indirect
  linking of Public Identifiers to their SED that significantly
  improves the scalability and manageability of the peering data.
  Additions and changes to SED information are reduced to a single
  operation on a SED Group or SED Record rather than millions of data
  updates to individual Public Identifier records that individually
  contain their peering data.  The substrate protocol MUST support the
  ability to Add, Get, and Delete SED Groups (refer to Section 7 for a
  generic description of various operations).

  A SED Group object MUST be uniquely identified by attributes as
  defined in the description of "ObjKeyType" in "Generic Object Key
  Type" (Section 5.2.1 of this document).




























Cartwright, et al.           Standards Track                   [Page 25]

RFC 7877                          SSPF                       August 2016


  The SedGrpType object structure is defined as follows:

  <complexType name="SedGrpType">
   <complexContent>
    <extension base="sppfb:BasicObjType">
     <sequence>
      <element name="sedGrpName" type="sppfb:ObjNameType"/>
      <element name="sedRecRef" type="sppfb:SedRecRefType"
               minOccurs="0" maxOccurs="unbounded"/>
      <element name="dgName" type="sppfb:ObjNameType"
               minOccurs="0" maxOccurs="unbounded"/>
      <element name="peeringOrg" type="sppfb:OrgIdType"
               minOccurs="0" maxOccurs="unbounded"/>
      <element name="sourceIdent" type="sppfb:SourceIdentType"
               minOccurs="0" maxOccurs="unbounded"/>
      <element name="isInSvc" type="boolean"/>
      <element name="priority" type="unsignedShort"/>
      <element name="ext" type="sppfb:ExtAnyType" minOccurs="0"/>
     </sequence>
    </extension>
   </complexContent>
  </complexType>

  <complexType name="SedRecRefType">
   <sequence>
    <element name="sedKey" type="sppfb:ObjKeyType"/>
    <element name="priority" type="unsignedShort"/>
    <element name="ext" type="sppfb:ExtAnyType" minOccurs="0"/>
   </sequence>
  </complexType>

  The SedGrpType object is composed of the following elements:

  o  base: All first-class objects extend BasicObjType (see
     Section 5.1).

  o  sedGrpName: The character string that contains the name of the SED
     Group.  It uniquely identifies this object within the context of
     the Registrant ID (a child element of the base element as
     described above).

  o  sedRecRef: Set of zero or more objects of type SedRecRefType that
     house the unique keys of the SED Records (containing the SED) that
     the SedGrpType object refers to and their relative priority within
     the context of this SED Group.






Cartwright, et al.           Standards Track                   [Page 26]

RFC 7877                          SSPF                       August 2016


  o  dgName: Set of zero or more names of DestGrpType object instances.
     Each dgName name, in association with this SED Group's Registrant
     ID, uniquely identifies a DestGrpType object instance whose
     associated Public Identifiers are reachable using the SED housed
     in this SED Group.  An intended side effect of this is that a SED
     Group cannot provide session establishment information for a
     Destination Group belonging to another Registrant.

  o  peeringOrg: Set of zero or more peering organization IDs that have
     accepted an offer to receive this SED Group's information.  Note
     that this identifier "peeringOrg" is an instance of OrgIdType.
     The set of peering organizations in this list is not directly
     settable or modifiable using the addSedGrpsRqst operation.  This
     set is instead controlled using the SED Offer and Accept
     operations.

  o  sourceIdent: Set of zero or more SourceIdentType object instances.
     These objects, described further below, house the source
     identification schemes and identifiers that are applied at
     resolution time as part of source-based routing algorithms for the
     SED Group.

  o  isInSvc: A boolean element that defines whether this SED Group is
     in service.  The SED contained in a SED Group that is in service
     is a candidate for inclusion in resolution responses for Public
     Identities residing in the Destination Group associated with this
     SED Group.  The session establishment information contained in a
     SED Group that is not in service is not a candidate for inclusion
     in resolution responses.

  o  priority: Priority value that can be used to provide a relative
     value weighting of one SED Group over another.  The manner in
     which this value is used, perhaps in conjunction with other
     factors, is a matter of policy.

  o  ext: Point of extensibility described in Section 3.3.

  As described above, the SED Group contains a set of references to SED
  Record objects.  A SED Record object is based on an abstract type:
  SedRecType.  The concrete types that use SedRecType as an extension
  base are NAPTRType, NSType, and URIType.  The definitions of these
  types are included in "SED Record" (Section 6.4 of this document).

  The SedGrpType object provides support for source-based routing via
  the peeringOrg data element and more granular source-based routing
  via the source identity element.  The source identity element
  provides the ability to specify zero or more of the following in
  association with a given SED Group: a regular expression that is



Cartwright, et al.           Standards Track                   [Page 27]

RFC 7877                          SSPF                       August 2016


  matched against the resolution client IP address, a regular
  expression that is matched against the root domain name(s), and/or a
  regular expression that is matched against the calling party URI(s).
  The result will be that, after identifying the visible SED Groups
  whose associated Destination Group(s) contains the lookup key being
  queried and whose peeringOrg list contains the querying
  organization's organization ID, the resolution server will evaluate
  the characteristics of the Source URI, Source IP address, and root
  domain of the lookup key being queried.  The resolution server then
  compares these criteria against the source identity criteria
  associated with the SED Groups.  The SED contained in SED Groups that
  have source-based routing criteria will only be included in the
  resolution response if one or more of the criteria matches the source
  criteria from the resolution request.  The source identity data
  element is of type SourceIdentType, whose structure is defined as
  follows:

  <complexType name="SourceIdentType">
   <sequence>
    <element name="sourceIdentRegex" type="sppfb:RegexType"/>
    <element name="sourceIdentScheme"
             type="sppfb:SourceIdentSchemeType"/>
    <element name="ext" type="sppfb:ExtAnyType" minOccurs="0"/>
   </sequence>
  </complexType>

  <simpleType name="SourceIdentSchemeType">
   <restriction base="token">
    <enumeration value="uri"/>
    <enumeration value="ip"/>
    <enumeration value="rootDomain"/>
   </restriction>
  </simpleType>

  The SourceIdentType object is composed of the following data
  elements:

  o  sourceIdentScheme: The source identification scheme that this
     source identification criteria applies to and that the associated
     sourceIdentRegex should be matched against.

  o  sourceIdentRegex: The regular expression that should be used to
     test for a match against the portion of the resolution request
     that is dictated by the associated sourceIdentScheme.

  o  ext: Point of extensibility described in Section 3.3.





Cartwright, et al.           Standards Track                   [Page 28]

RFC 7877                          SSPF                       August 2016


6.4.  SED Record

  SED Group represents a combined grouping of SED Records that define
  SED.  However, SED Records need not be created to just serve a single
  SED Group.  SED Records can be created and managed to serve multiple
  SED Groups.  As a result, a change, for example, to the properties of
  a network node used for multiple routes would necessitate just a
  single update operation to change the properties of that node.  The
  change would then be reflected in all the SED Groups whose SED Record
  set contains a reference to that node.  The substrate protocol MUST
  support the ability to Add, Get, and Delete SED Records (refer to
  Section 7 for a generic description of various operations).

  A SED Record object MUST be uniquely identified by attributes as
  defined in the description of "ObjKeyType" in "Generic Object Key
  Type" (Section 5.2.1 of this document).

  The SedRecType object structure is defined as follows:

  <complexType name="SedRecType" abstract="true">
   <complexContent>
    <extension base="sppfb:BasicObjType">
     <sequence>
      <element name="sedName" type="sppfb:ObjNameType"/>
      <element name="sedFunction" type="sppfb:SedFunctionType"
               minOccurs="0"/>
      <element name="isInSvc" type="boolean"/>
      <element name="ttl" type="positiveInteger" minOccurs="0"/>
     </sequence>
    </extension>
   </complexContent>
  </complexType>

  <simpleType name="SedFunctionType">
   <restriction base="token">
    <enumeration value="routing"/>
    <enumeration value="lookup"/>
   </restriction>
  </simpleType>

  The SedRecType object is composed of the following elements:

  o  base: All first-class objects extend BasicObjType (see
     Section 5.1).







Cartwright, et al.           Standards Track                   [Page 29]

RFC 7877                          SSPF                       August 2016


  o  sedName: The character string that contains the name of the SED
     Record.  It uniquely identifies this object within the context of
     the Registrant ID (a child element of the base element as
     described above).

  o  sedFunction: As described in [RFC6461], SED falls primarily into
     one of two categories or functions: LUF and LRF.  To remove any
     ambiguity as to the function a SED Record is intended to provide,
     this optional element allows the provisioning party to make its
     intentions explicit.

  o  isInSvc: A boolean element that defines whether or not this SED
     Record is in service.  The session establishment information
     contained in a SED Record that is in service is a candidate for
     inclusion in resolution responses for TNs that are either directly
     associated to this SED Record or for Public Identities residing in
     a Destination Group that is associated to a SED Group, which, in
     turn, has an association to this SED Record.

  o  ttl: Number of seconds that an addressing server may cache a
     particular SED Record.

  As described above, SED Records are based on abstract type
  SedRecType.  The concrete types that use SedRecType as an extension
  base are NAPTRType, NSType, and URIType.  The definitions of these
  types are included below.  The NAPTRType object is comprised of the
  data elements necessary for a Naming Authority Pointer (NAPTR) (see
  [RFC3403]) that contains routing information for a SED Group.  The
  NSType object is comprised of the data elements necessary for a DNS
  name server that points to another DNS server that contains the
  desired routing information.  The NSType is relevant only when the
  resolution protocol is ENUM (see [RFC6116]).  The URIType object is
  comprised of the data elements necessary to house a URI.

  The data provisioned in a Registry can be leveraged for many purposes
  and queried using various protocols including SIP, ENUM, and others.
  As such, the resolution data represented by the SED Records must be
  in a form suitable for transport using one of these protocols.  In
  the NAPTRType, for example, if the URI is associated with a
  Destination Group, the user part of the replacement string <uri> that
  may require the Public Identifier cannot be preset.  As a SIP
  Redirect, the resolution server will apply <ere> pattern on the input
  Public Identifier in the query and process the replacement string by
  substituting any back references in the <uri> to arrive at the final
  URI that is returned in the SIP Contact header.  For an ENUM query,
  the resolution server will simply return the values of the <ere> and
  <uri> members of the URI.




Cartwright, et al.           Standards Track                   [Page 30]

RFC 7877                          SSPF                       August 2016


  <complexType name="NAPTRType">
   <complexContent>
    <extension base="sppfb:SedRecType">
     <sequence>
      <element name="order" type="unsignedShort"/>
      <element name="flags" type="sppfb:FlagsType" minOccurs="0"/>
      <element name="svcs" type="sppfb:SvcType"/>
      <element name="regx" type="sppfb:RegexParamType" minOccurs="0"/>
      <element name="repl" type="sppfb:ReplType" minOccurs="0"/>
      <element name="ext" type="sppfb:ExtAnyType" minOccurs="0"/>
     </sequence>
    </extension>
   </complexContent>
  </complexType>

  <complexType name="NSType">
   <complexContent>
    <extension base="sppfb:SedRecType">
     <sequence>
      <element name="hostName" type="token"/>
      <element name="ipAddr" type="sppfb:IPAddrType"
               minOccurs="0" maxOccurs="unbounded"/>
      <element name="ext" type="sppfb:ExtAnyType" minOccurs="0"/>
     </sequence>
    </extension>
   </complexContent>
  </complexType>

  <complexType name="IPAddrType">
   <sequence>
    <element name="addr" type="sppfb:AddrStringType"/>
    <element name="ext" type="sppfb:ExtAnyType" minOccurs="0"/>
   </sequence>
   <attribute name="type" type="sppfb:IPType" default="IPv4"/>
  </complexType>

  <simpleType name="IPType">
   <restriction base="token">
    <enumeration value="IPv4"/>
    <enumeration value="IPv6"/>
   </restriction>
  </simpleType>

  <complexType name="URIType">
   <complexContent>
    <extension base="sppfb:SedRecType">
     <sequence>
      <element name="ere" type="token" default="^(.*)$"/>



Cartwright, et al.           Standards Track                   [Page 31]

RFC 7877                          SSPF                       August 2016


      <element name="uri" type="anyURI"/>
      <element name="ext" type="sppfb:ExtAnyType" minOccurs="0"/>
     </sequence>
    </extension>
   </complexContent>
  </complexType>

  <simpleType name="flagsType">
   <restriction base="token">
    <length value="1"/>
    <pattern value="[A-Z]|[a-z]|[0-9]"/>
   </restriction>
  </simpleType>

  The NAPTRType object is composed of the following elements:

  o  order: Order value in an ENUM NAPTR, relative to other NAPTRType
     objects in the same SED Group.

  o  svcs: ENUM service(s) that is served by the SBE.  This field's
     value must be of the form specified in [RFC6116] (e.g.,
     E2U+pstn:sip+sip).  The allowable values are a matter of policy
     and are not limited by this protocol.

  o  regx: NAPTR's regular expression field.  If this is not included,
     then the repl field must be included.

  o  repl: NAPTR replacement field; it should only be provided if the
     regx field is not provided; otherwise, the server will ignore it.

  o  ext: Point of extensibility described in Section 3.3.

  The NSType object is composed of the following elements:

  o  hostName: Root-relative host name of the name server.

  o  ipAddr: Zero or more objects of type IpAddrType.  Each object
     holds an IP Address and the IP Address type ("IPv4" or "IPv6").

  o  ext: Point of extensibility described in Section 3.3.

  The URIType object is composed of the following elements:

  o  ere: The POSIX Extended Regular Expression (ere) as defined in
     [RFC3986].






Cartwright, et al.           Standards Track                   [Page 32]

RFC 7877                          SSPF                       August 2016


  o  uri: the URI as defined in [RFC3986].  In some cases, this will
     serve as the replacement string, and it will be left to the
     resolution server to arrive at the final usable URI.

6.5.  SED Group Offer

  The list of peer organizations whose resolution responses can include
  the SED contained in a given SED Group is controlled by the
  organization to which a SED Group object belongs (its Registrant) and
  the peer organization that submits resolution requests (a data
  recipient, also known as a peering organization).  The Registrant
  offers access to a SED Group by submitting a SED Group Offer.  The
  data recipient can then accept or reject that offer.  Not until
  access to a SED Group has been offered and accepted will the data
  recipient's organization ID be included in the peeringOrg list in a
  SED Group object, and that SED Group's peering information becomes a
  candidate for inclusion in the responses to the resolution requests
  submitted by that data recipient.  The substrate protocol MUST
  support the ability to Add, Get, Delete, Accept, and Reject SED Group
  Offers (refer to Section 7 for a generic description of various
  operations).

  A SED Group Offer object MUST be uniquely identified by attributes as
  defined in the description of "SedGrpOfferKeyType" in "Derived Object
  Key Types" (Section 5.2.2 of this document).


























Cartwright, et al.           Standards Track                   [Page 33]

RFC 7877                          SSPF                       August 2016


  The SedGrpOfferType object structure is defined as follows:

  <complexType name="SedGrpOfferType">
   <complexContent>
    <extension base="sppfb:BasicObjType">
     <sequence>
      <element name="sedGrpOfferKey" type="sppfb:SedGrpOfferKeyType"/>
      <element name="status" type="sppfb:SedGrpOfferStatusType"/>
      <element name="offerDateTime" type="dateTime"/>
      <element name="acceptDateTime" type="dateTime" minOccurs="0"/>
      <element name="ext" type="sppfb:ExtAnyType" minOccurs="0"/>
     </sequence>
    </extension>
   </complexContent>
  </complexType>

  <complexType name="SedGrpOfferKeyType" abstract="true">
   <annotation>
    <documentation>
    -- Generic type that represents the key for a SED Group Offer. Must
       be defined in concrete form in a substrate "protocol"
       specification. --
    </documentation>
   </annotation>
  </complexType>

  <simpleType name="SedGrpOfferStatusType">
   <restriction base="token">
    <enumeration value="offered"/>
    <enumeration value="accepted"/>
   </restriction>
  </simpleType>

  The SedGrpOfferType object is composed of the following elements:

  o  base: All first-class objects extend BasicObjType (see
     Section 5.1).

  o  sedGrpOfferKey: The object that identifies the SED that is or has
     been offered and the organization to which it is or has been
     offered.

  o  status: The status of the offer, offered or accepted.  The server
     controls the status.  It is automatically set to "offered"
     whenever a new SED Group Offer is added and is automatically set
     to "accepted" if and when that offer is accepted.  The value of
     the element is ignored when passed in by the client.




Cartwright, et al.           Standards Track                   [Page 34]

RFC 7877                          SSPF                       August 2016


  o  offerDateTime: Date and time in UTC when the SED Group Offer was
     added.

  o  acceptDateTime: Date and time in UTC when the SED Group Offer was
     accepted.

6.6.  Egress Route

  In a high-availability environment, the originating SSP likely has
  more than one egress path to the ingress SBE of the target SSP.  If
  the originating SSP wants to exercise greater control and choose a
  specific egress SBE to be associated to the target ingress SBE, it
  can do so using the EgrRteType object.

  An Egress Route object MUST be uniquely identified by attributes as
  defined in the description of "ObjKeyType" in "Generic Object Key
  Type" (Section 5.2.1 of this document).

  Assume that the target SSP has offered, as part of its SED, to share
  one or more Ingress Routes and that the originating SSP has accepted
  the offer.  In order to add the Egress Route to the Registry, the
  originating SSP uses a valid regular expression to rewrite the
  Ingress Route in order to include the egress SBE information.  Also,
  more than one Egress Route can be associated with a given Ingress
  Route in support of fault-tolerant configurations.  The supporting
  SPPF structure provides a way to include route precedence information
  to help manage traffic to more than one outbound egress SBE.

  The substrate protocol MUST support the ability to Add, Get, and
  Delete Egress Routes (refer to Section 7 for a generic description of
  various operations).  The EgrRteType object structure is defined as
  follows:

  <complexType name="EgrRteType">
   <complexContent>
    <extension base="sppfb:BasicObjType">
     <sequence>
      <element name="egrRteName" type="sppfb:ObjNameType"/>
      <element name="pref" type="unsignedShort"/>
      <element name="regxRewriteRule" type="sppfb:RegexParamType"/>
      <element name="ingrSedGrp" type="sppfb:ObjKeyType"
               minOccurs="0" maxOccurs="unbounded"/>
      <element name="svcs" type="sppfb:SvcType" minOccurs="0"/>
      <element name="ext" type="sppfb:ExtAnyType" minOccurs="0"/>
     </sequence>
    </extension>
   </complexContent>
  </complexType>



Cartwright, et al.           Standards Track                   [Page 35]

RFC 7877                          SSPF                       August 2016


  The EgrRteType object is composed of the following elements:

  o  base: All first-class objects extend BasicObjType (see
     Section 5.1).

  o  egrRteName: The name of the Egress Route.

  o  pref: The preference of this Egress Route relative to other Egress
     Routes that may get selected when responding to a resolution
     request.

  o  regxRewriteRule: The regular expression rewrite rule that should
     be applied to the regular expression of the ingress NAPTR(s) that
     belongs to the Ingress Route.

  o  ingrSedGrp: The ingress SED Group that the Egress Route should be
     used for.

  o  svcs: ENUM service(s) that is served by an Egress Route.  This
     element is used to identify the ingress NAPTRs associated with the
     SED Group to which an Egress Route's regxRewriteRule should be
     applied.  If no ENUM service(s) is associated with an Egress
     Route, then the Egress Route's regxRewriteRule should be applied
     to all the NAPTRs associated with the SED Group.  This field's
     value must be of the form specified in [RFC6116] (e.g.,
     E2U+pstn:sip+sip).  The allowable values are a matter of policy
     and are not limited by this protocol.

  o  ext: Point of extensibility described in Section 3.3.

7.  Framework Operations

  In addition to the operation-specific object types, all operations
  MAY specify the minor version of the protocol that when used in
  conjunction with the major version (which can be, for instance,
  specified in the protocol Namespace) can serve to identify the
  version of the SPPF protocol that the client is using.  If the minor
  version is not specified, the latest minor version supported by the
  SPPF server for the given major version will be used.  Additionally,
  operations that may potentially modify persistent protocol objects
  SHOULD include a transaction ID as well.










Cartwright, et al.           Standards Track                   [Page 36]

RFC 7877                          SSPF                       August 2016


7.1.  Add Operation

  Any conforming substrate "protocol" specification MUST provide a
  definition for the operation that adds one or more SPPF objects into
  the Registry.  If the object, as identified by the request attributes
  that form part of the object's key, does not exist, then the Registry
  MUST create the object.  If the object does exist, then the Registry
  MUST replace the current properties of the object with the properties
  passed in as part of the Add operation.

  Note that this effectively allows modification of a preexisting
  object.

  If the entity that issued the command is not authorized to perform
  this operation, an appropriate error message MUST be returned from
  amongst the response messages defined in "Response Message Types"
  (Section 5.3 of this document).

7.2.  Delete Operation

  Any conforming substrate "protocol" specification MUST provide a
  definition for the operation that deletes one or more SPPF objects
  from the Registry using the object's key.

  If the entity that issued the command is not authorized to perform
  this operation, an appropriate error message MUST be returned from
  amongst the response messages defined in "Response Message Types"
  (Section 5.3 of this document).

  When an object is deleted, any references to that object must of
  course also be removed as the SPPF server implementation fulfills the
  deletion request.  Furthermore, the deletion of a composite object
  must also result in the deletion of the objects it contains.  As a
  result, the following rules apply to the deletion of SPPF object
  types:

  o  Destination Groups: When a Destination Group is deleted, any
     cross-references between that destination group and any SED Group
     must be automatically removed by the SPPF implementation as part
     of fulfilling the deletion request.  Similarly, any cross-
     references between that Destination Group and any Public
     Identifier must be removed by the SPPF implementation.

  o  SED Groups: When a SED Group is deleted, any references between
     that SED Group and any Destination Group must be automatically
     removed by the SPPF implementation as part of fulfilling the
     deletion request.  Similarly, any cross-references between that
     SED Group and any SED Records must be removed by the SPPF



Cartwright, et al.           Standards Track                   [Page 37]

RFC 7877                          SSPF                       August 2016


     implementation as part of fulfilling the deletion request.
     Furthermore, SED Group Offers relating to that SED Group must also
     be deleted.

  o  SED Records: When a SED Record is deleted, any cross-references
     between that SED Record and any SED Group must be removed by the
     SPPF implementation as part of fulfilling the deletion request.
     Similarly, any reference between that SED Record and any Public
     Identifier must be removed by the SPPF implementation.

  o  Public Identifiers: When a Public Identifier is deleted, any
     cross-references between that Public Identifier and any referenced
     Destination Group must be removed by the SPPF implementation as
     part of fulfilling the deletion request.  Any references to SED
     Records associated directly to that Public Identifier must also be
     deleted by the SPPF implementation.

  Deletes MUST be atomic.

7.3.  Get Operations

  At times, on behalf of the Registrant, the Registrar may need to get
  information about SPPF objects that were previously provisioned in
  the Registry.  A few examples include logging, auditing, and pre-
  provisioning dependency checking.  This query mechanism is limited to
  aid provisioning scenarios and should not be confused with query
  protocols provided as part of the resolution system (e.g., ENUM and
  SIP).

  Any conforming "protocol" specification MUST provide a definition for
  the operation that queries the details of one or more SPPF objects
  from the Registry using the object's key.  If the entity that issued
  the command is not authorized to perform this operation, an
  appropriate error message MUST be returned from among the response
  messages defined in Section 5.3.

  If the response to the Get operation includes an object(s) that
  extends the BasicObjType, the Registry MUST include the "cDate" and
  "mDate", if applicable.

7.4.  Accept Operations

  In SPPF, a SED Group Offer can be accepted or rejected by, or on
  behalf of, the Registrant to which the SED Group has been offered
  (refer to Section 6.5 of this document for a description of the SED
  Group Offer object).  The Accept operation is used to accept the SED
  Group Offers.  Any conforming substrate "protocol" specification MUST
  provide a definition for the operation to accept SED Group Offers by,



Cartwright, et al.           Standards Track                   [Page 38]

RFC 7877                          SSPF                       August 2016


  or on behalf of, the Registrant, using the SED Group Offer object
  key.

  Not until access to a SED Group has been offered and accepted will
  the Registrant's organization ID be included in the peeringOrg list
  in that SED Group object, and that SED Group's peering information
  becomes a candidate for inclusion in the responses to the resolution
  requests submitted by that Registrant.  A SED Group Offer that is in
  the "offered" status is accepted by, or on behalf of, the Registrant
  to which it has been offered.  When the SED Group Offer is accepted,
  the SED Group Offer is moved to the "accepted" status and the data
  recipient's organization ID is added into the list of peerOrgIds for
  that SED Group.

  If the entity that issued the command is not authorized to perform
  this operation, an appropriate error message MUST be returned from
  amongst the response messages defined in "Response Message Types"
  (Section 5.3 of this document).

7.5.  Reject Operations

  In SPPF, a SED Group Offer object can be accepted or rejected by, or
  on behalf of, the Registrant to which the SED Group has been offered
  (refer to "Framework Data Model Objects", Section 6 of this document,
  for a description of the SED Group Offer object).  Furthermore, that
  offer may be rejected, regardless of whether or not it has been
  previously accepted.  The Reject operation is used to reject the SED
  Group Offer.  When the SED Group Offer is rejected, that SED Group
  Offer is deleted, and, if appropriate, the data recipient's
  organization ID is removed from the list of peeringOrg IDs for that
  SED Group.  Any conforming substrate "protocol" specification MUST
  provide a definition for the operation to reject SED Group Offers by,
  or on behalf of, the Registrant, using the SED Group Offer object
  key.

  If the entity that issued the command is not authorized to perform
  this operation, an appropriate error message MUST be returned from
  among the response messages defined in "Response Message Types"
  (Section 5.3 of this document).

7.6.  Get Server Details Operation

  In SPPF, the Get Server Details operation can be used to request
  certain details about the SPPF server that include the SPPF server's
  current status and the major/minor version of the SPPF protocol
  supported by the SPPF server.





Cartwright, et al.           Standards Track                   [Page 39]

RFC 7877                          SSPF                       August 2016


  Any conforming substrate "protocol" specification MUST provide a
  definition for the operation to request such details from the SPPF
  server.  If the entity that issued the command is not authorized to
  perform this operation, an appropriate error message MUST be returned
  from among the response messages defined in "Response Message Types"
  (Section 5.3 of this document).

8.  XML Considerations

  XML serves as the encoding format for SPPF, allowing complex
  hierarchical data to be expressed in a text format that can be read,
  saved, and manipulated with both traditional text tools and tools
  specific to XML.

  XML is case sensitive.  Unless stated otherwise, the character casing
  of XML specifications in this document MUST be preserved to develop a
  conforming specification.

  This section discusses a small number of XML-related considerations
  pertaining to SPPF.

8.1.  Namespaces

  All SPPF elements are defined in the Namespaces in the "IANA
  Considerations" and "Formal Framework Specification" sections of this
  document.

8.2.  Versioning and Character Encoding

  All XML instances SHOULD begin with an <?xml?> declaration to
  identify the version of XML that is being used, optionally identify
  use of the character encoding used, and optionally provide a hint to
  an XML parser that an external schema file is needed to validate the
  XML instance.

  Conformant XML parsers recognize both UTF-8 (defined in [RFC3629])
  and UTF-16 (defined in [RFC2781]); per [RFC2277], UTF-8 is the
  RECOMMENDED character encoding for use with SPPF.

  Character encodings other than UTF-8 and UTF-16 are allowed by XML.
  UTF-8 is the default encoding assumed by XML in the absence of an
  "encoding" attribute or a byte order mark (BOM); thus, the "encoding"
  attribute in the XML declaration is OPTIONAL if UTF-8 encoding is
  used.  SPPF clients and servers MUST accept a UTF-8 BOM if present,
  though emitting a UTF-8 BOM is NOT RECOMMENDED.






Cartwright, et al.           Standards Track                   [Page 40]

RFC 7877                          SSPF                       August 2016


  Example XML declarations:

  <?xml version="1.0" encoding="UTF-8" standalone="no"?>

9.  Security Considerations

  Many SPPF implementations manage data that is considered confidential
  and critical.  Furthermore, SPPF implementations can support
  provisioning activities for multiple Registrars and Registrants.  As
  a result, any SPPF implementation must address the requirements for
  confidentiality, authentication, and authorization.

9.1.  Confidentiality and Authentication

  With respect to confidentiality and authentication, the substrate
  protocol requirements section of this document contains security
  properties that the substrate protocol must provide, so that
  authenticated endpoints can exchange data confidentially and with
  integrity protection.  Refer to Section 4 of this document and
  [RFC7878] for the specific solutions to authentication and
  confidentiality.

9.2.  Authorization

  With respect to authorization, the SPPF server implementation must
  define and implement a set of authorization rules that precisely
  address (1) which Registrars will be authorized to create/modify/
  delete each SPPF object type for a given Registrant(s) and (2) which
  Registrars will be authorized to view/get each SPPF object type for a
  given Registrant(s).  These authorization rules are a matter of
  policy and are not specified within the context of SPPF.  However,
  any SPPF implementation must specify these authorization rules in
  order to function in a reliable and safe manner.

9.3.  Denial of Service

  In general, guidance on Denial-of-Service (DoS) issues is given in
  "Internet Denial of Service Considerations" [RFC4732], which also
  gives a general vocabulary for describing the DoS issue.

  SPPF is a high-level client-server protocol that can be implemented
  on lower-level mechanisms such as remote procedure call and web-
  service API protocols.  As such, it inherits any Denial-of-Service
  issues inherent to the specific lower-level mechanism used for any
  implementation of SPPF.  SPPF also has its own set of higher-level
  exposures that are likely to be independent of lower-layer mechanism
  choices.




Cartwright, et al.           Standards Track                   [Page 41]

RFC 7877                          SSPF                       August 2016


9.3.1.  DoS Issues Inherited from the Substrate Mechanism

  In general, an SPPF implementation is dependent on the selection and
  implementation of a lower-level substrate protocol and a binding
  between that protocol and SPPF.  The archetypal SPPF implementation
  uses XML [W3C.REC-xml-20081126] representation in a SOAP [SOAPREF]
  request/response framework over HTTP [RFC7230], probably also uses
  Transport Layer Security (TLS) [RFC5246] for on-the-wire data
  integrity and participant authentication, and might use HTTP Digest
  authentication [RFC2069].

  The typical deployment scenario for SPPF is to have servers in a
  managed facility; therefore, techniques such as Network Ingress
  Filtering [RFC2827] are generally applicable.  In short, any DoS
  mechanism affecting a typical HTTP implementation would affect such
  an SPPF implementation; therefore, the mitigation tools for HTTP in
  general also apply to SPPF.

  SPPF does not directly specify an authentication mechanism; instead,
  it relies on the lower-level substrate protocol to provide for
  authentication.  In general, authentication is an expensive
  operation, and one apparent attack vector is to flood an SPPF server
  with repeated requests for authentication, thereby exhausting its
  resources.  Therefore, SPPF implementations SHOULD be prepared to
  handle authentication floods, perhaps by noting repeated failed login
  requests from a given source address and blocking that source
  address.

9.3.2.  DoS Issues Specific to SPPF

  The primary defense mechanism against DoS within SPPF is
  authentication.  Implementations MUST tightly control access to the
  SPPF service, SHOULD implement DoS and other policy control
  screening, and MAY employ a variety of policy violation reporting and
  response measures such as automatic blocking of specific users and
  alerting of operations personnel.  In short, the primary SPPF
  response to DoS-like activity by a user is to block that user or
  subject their actions to additional review.

  SPPF allows a client to submit multiple-element or "batch" requests
  that may insert or otherwise affect a large amount of data with a
  single request.  In the simplest case, the server progresses
  sequentially through each element in a batch, completing one before
  starting the next.  Mid-batch failures are handled by stopping the
  batch and rolling back the data store to its pre-request state.  This
  "stop and roll back" design provides a DoS opportunity.  A hostile
  client could repeatedly issue large batch requests with one or more
  failing elements, causing the server to repeatedly stop and roll back



Cartwright, et al.           Standards Track                   [Page 42]

RFC 7877                          SSPF                       August 2016


  large transactions.  The suggested response is to monitor clients for
  such failures and take administrative action (such as blocking the
  user) when an excessive number of rollbacks is reported.

  An additional suggested response is for an implementer to set their
  maximum allowable XML message size and their maximum allowable batch
  size at a level that they feel protects their operational instance,
  given the hardware sizing they have in place and the expected load
  and size needs that their users expect.

9.4.  Information Disclosure

  It is not uncommon for the logging systems to document on-the-wire
  messages for various purposes, such as debugging, auditing, and
  tracking.  At the minimum, the various support and administration
  staff will have access to these logs.  Also, if an unprivileged user
  gains access to the SPPF deployments and/or support systems, it will
  have access to the information that is potentially deemed
  confidential.  To manage information disclosure concerns beyond the
  substrate level, SPPF implementations MAY provide support for
  encryption at the SPPF object level.

9.5.  Non-repudiation

  In some situations, it may be required to protect against denial of
  involvement (see [RFC4949]) and tackle non-repudiation concerns in
  regard to SPPF messages.  This type of protection is useful to
  satisfy authenticity concerns related to SPPF messages beyond the
  end-to-end connection integrity, confidentiality, and authentication
  protection that the substrate layer provides.  This is an optional
  feature, and some SPPF implementations MAY provide support for it.

9.6.  Replay Attacks

  Anti-replay protection ensures that a given SPPF object replayed at a
  later time won't affect the integrity of the system.  SPPF provides
  at least one mechanism to fight against replay attacks.  Use of the
  optional client transaction identifier allows the SPPF client to
  correlate the request message with the response and to be sure that
  it is not a replay of a server response from earlier exchanges.  Use
  of unique values for the client transaction identifier is highly
  encouraged to avoid chance matches to a potential replay message.









Cartwright, et al.           Standards Track                   [Page 43]

RFC 7877                          SSPF                       August 2016


9.7.  Compromised or Malicious Intermediary

  The SPPF client or Registrar can be a separate entity acting on
  behalf of the Registrant in facilitating provisioning transactions to
  the Registry.  Therefore, even though the substrate layer provides
  end-to-end protection for each specific SPPP connection between
  client and server, data might be available in clear text before or
  after it traverses an SPPP connection.  Therefore, a
  man-in-the-middle attack by one of the intermediaries is a
  possibility that could affect the integrity of the data that belongs
  to the Registrant and/or expose peering data to unintended actors.

10.  Internationalization Considerations

  Character encodings to be used for SPPF elements are described in
  Section 8.2.  The use of time elements in the protocol is specified
  in Section 3.2.  Where human-readable messages that are presented to
  an end user are used in the protocol, those messages SHOULD be tagged
  according to [RFC5646], and the substrate protocol MUST support a
  respective mechanism to transmit such tags together with those human-
  readable messages.

11.  IANA Considerations

11.1.  URN Assignments

  This document uses URNs to describe XML Namespaces and XML Schemas
  conforming to a Registry mechanism described in [RFC3688].

  Two URI assignments have been made:

  Registration for the SPPF XML Namespace:
  urn:ietf:params:xml:ns:sppf:base:1
  Registrant Contact: The IESG
  XML: None.  Namespace URIs do not represent an XML specification.

  Registration request for the XML Schema:

  URI: urn:ietf:params:xml:schema:sppf:1
  Registrant Contact: IESG
  XML: See "Formal Specification" (Section 12 of this document).










Cartwright, et al.           Standards Track                   [Page 44]

RFC 7877                          SSPF                       August 2016


11.2.  Organization Identifier Namespace Registry

  IANA has created and will maintain a registry titled "SPPF OrgIdType
  Namespaces".  The formal syntax is described in Section 5.1.

  Assignments consist of the OrgIdType Namespace string and the
  definition of the associated Namespace.  This document makes the
  following initial assignment for the OrgIdType Namespaces:

        OrgIdType Namespace string                       Namespace
        --------------------------                       ---------
        IANA Enterprise Numbers                          iana-en

  Future assignments are to be made through the well-known IANA Policy
  "RFC Required" (see Section 4.1 of [RFC5226]).  Such assignments will
  typically be requested when a new Namespace for identification of SPs
  is defined.

12.  Formal Specification

  This section provides the XSD for the SPPF protocol.

  <?xml version="1.0" encoding="UTF-8"?>
  <schema xmlns:sppfb="urn:ietf:params:xml:ns:sppf:base:1"
  xmlns="http://www.w3.org/2001/XMLSchema"
  targetNamespace="urn:ietf:params:xml:ns:sppf:base:1"
  elementFormDefault="qualified" xml:lang="EN">
   <annotation>
    <documentation>
     ---- Generic object key types to be defined by specific
          substrate/architecture.  The types defined here can
          be extended by the specific architecture to
          define the Object Identifiers. ----
    </documentation>
   </annotation>
   <complexType name="ObjKeyType"
    abstract="true">
    <annotation>
     <documentation>
      ---- Generic type that represents the
           key for various objects in SPPF. ----
     </documentation>
    </annotation>
   </complexType>







Cartwright, et al.           Standards Track                   [Page 45]

RFC 7877                          SSPF                       August 2016


   <complexType name="SedGrpOfferKeyType" abstract="true">
    <complexContent>
     <extension base="sppfb:ObjKeyType">
      <annotation>
       <documentation>
       ---- Generic type that represents
            the key for a SED Group Offer. ----
       </documentation>
      </annotation>
     </extension>
    </complexContent>
   </complexType>

   <complexType name="PubIdKeyType" abstract="true">
    <complexContent>
     <extension base="sppfb:ObjKeyType">
      <annotation>
       <documentation>
        ----Generic type that
        represents the key
        for a Pub ID. ----
       </documentation>
      </annotation>
     </extension>
    </complexContent>
   </complexType>

   <annotation>
    <documentation>
      ---- Object Type Definitions ----
    </documentation>
   </annotation>

   <complexType name="SedGrpType">
    <complexContent>
     <extension base="sppfb:BasicObjType">
      <sequence>
       <element name="sedGrpName" type="sppfb:ObjNameType"/>
       <element name="sedRecRef" type="sppfb:SedRecRefType"
                minOccurs="0" maxOccurs="unbounded"/>
       <element name="dgName" type="sppfb:ObjNameType"
                minOccurs="0" maxOccurs="unbounded"/>
       <element name="peeringOrg" type="sppfb:OrgIdType"
                minOccurs="0" maxOccurs="unbounded"/>
       <element name="sourceIdent" type="sppfb:SourceIdentType"
                minOccurs="0" maxOccurs="unbounded"/>
       <element name="isInSvc" type="boolean"/>
       <element name="priority" type="unsignedShort"/>



Cartwright, et al.           Standards Track                   [Page 46]

RFC 7877                          SSPF                       August 2016


       <element name="ext"
       type="sppfb:ExtAnyType" minOccurs="0"/>
      </sequence>
     </extension>
    </complexContent>
   </complexType>
   <complexType name="DestGrpType">
    <complexContent>
     <extension base="sppfb:BasicObjType">
      <sequence>
       <element name="dgName"
       type="sppfb:ObjNameType"/>
      </sequence>
     </extension>
    </complexContent>
   </complexType>
   <complexType name="PubIdType" abstract="true">
    <complexContent>
     <extension base="sppfb:BasicObjType">
      <sequence>
       <element name="dgName" type="sppfb:ObjNameType"
                minOccurs="0" maxOccurs="unbounded"/>
      </sequence>
     </extension>
    </complexContent>
   </complexType>
   <complexType name="TNType">
    <complexContent>
     <extension base="sppfb:PubIdType">
      <sequence>
       <element name="tn" type="sppfb:NumberValType"/>
       <element name="corInfo" type="sppfb:CORInfoType" minOccurs="0"/>
       <element name="sedRecRef" type="sppfb:SedRecRefType"
                minOccurs="0" maxOccurs="unbounded"/>
      </sequence>
     </extension>
    </complexContent>
   </complexType>
   <complexType name="TNRType">
    <complexContent>
     <extension base="sppfb:PubIdType">
      <sequence>
       <element name="range" type="sppfb:NumberRangeType"/>
       <element name="corInfo" type="sppfb:CORInfoType" minOccurs="0"/>
      </sequence>
     </extension>
    </complexContent>
   </complexType>



Cartwright, et al.           Standards Track                   [Page 47]

RFC 7877                          SSPF                       August 2016


   <complexType name="TNPType">
    <complexContent>
     <extension base="sppfb:PubIdType">
      <sequence>
       <element name="tnPrefix" type="sppfb:NumberValType"/>
       <element name="corInfo" type="sppfb:CORInfoType" minOccurs="0"/>
      </sequence>
     </extension>
    </complexContent>
   </complexType>
   <complexType name="RNType">
    <complexContent>
     <extension base="sppfb:PubIdType">
      <sequence>
       <element name="rn" type="sppfb:NumberValType"/>
       <element name="corInfo" type="sppfb:CORInfoType" minOccurs="0"/>
      </sequence>
     </extension>
    </complexContent>
   </complexType>
    <complexType name="URIPubIdType">
    <complexContent>
     <extension base="sppfb:PubIdType">
      <sequence>
       <element name="uri" type="anyURI"/>
       <element name="ext" type="sppfb:ExtAnyType" minOccurs="0"/>
      </sequence>
     </extension>
    </complexContent>
   </complexType>
   <complexType name="SedRecType" abstract="true">
    <complexContent>
     <extension base="sppfb:BasicObjType">
      <sequence>
       <element name="sedName" type="sppfb:ObjNameType"/>
       <element name="sedFunction" type="sppfb:SedFunctionType"
                minOccurs="0"/>
       <element name="isInSvc" type="boolean"/>
       <element name="ttl" type="positiveInteger" minOccurs="0"/>
      </sequence>
     </extension>
    </complexContent>
   </complexType>
   <complexType name="NAPTRType">
    <complexContent>
     <extension base="sppfb:SedRecType">
      <sequence>
       <element name="order" type="unsignedShort"/>



Cartwright, et al.           Standards Track                   [Page 48]

RFC 7877                          SSPF                       August 2016


       <element name="flags" type="sppfb:FlagsType" minOccurs="0"/>
       <element name="svcs" type="sppfb:SvcType"/>
       <element name="regx" type="sppfb:RegexParamType" minOccurs="0"/>
       <element name="repl" type="sppfb:ReplType" minOccurs="0"/>
       <element name="ext" type="sppfb:ExtAnyType" minOccurs="0"/>
      </sequence>
     </extension>
    </complexContent>
   </complexType>
   <complexType name="NSType">
    <complexContent>
     <extension base="sppfb:SedRecType">
      <sequence>
       <element name="hostName" type="token"/>
       <element name="ipAddr" type="sppfb:IPAddrType"
                minOccurs="0" maxOccurs="unbounded"/>
       <element name="ext" type="sppfb:ExtAnyType" minOccurs="0"/>
      </sequence>
     </extension>
    </complexContent>
   </complexType>
   <complexType name="URIType">
    <complexContent>
     <extension base="sppfb:SedRecType">
      <sequence>
       <element name="ere" type="token" default="^(.*)$"/>
       <element name="uri" type="anyURI"/>
       <element name="ext" type="sppfb:ExtAnyType" minOccurs="0"/>
      </sequence>
     </extension>
    </complexContent>
   </complexType>
   <complexType name="SedGrpOfferType">
    <complexContent>
     <extension base="sppfb:BasicObjType">
      <sequence>
       <element name="sedGrpOfferKey" type="sppfb:SedGrpOfferKeyType"/>
       <element name="status" type="sppfb:SedGrpOfferStatusType"/>
       <element name="offerDateTime" type="dateTime"/>
       <element name="acceptDateTime" type="dateTime" minOccurs="0"/>
       <element name="ext" type="sppfb:ExtAnyType" minOccurs="0"/>
      </sequence>
     </extension>
    </complexContent>
   </complexType>
   <complexType name="EgrRteType">
    <complexContent>
     <extension base="sppfb:BasicObjType">



Cartwright, et al.           Standards Track                   [Page 49]

RFC 7877                          SSPF                       August 2016


      <sequence>
       <element name="egrRteName" type="sppfb:ObjNameType"/>
       <element name="pref" type="unsignedShort"/>
       <element name="regxRewriteRule" type="sppfb:RegexParamType"/>
       <element name="ingrSedGrp" type="sppfb:ObjKeyType"
                minOccurs="0" maxOccurs="unbounded"/>
       <element name="svcs" type="sppfb:SvcType" minOccurs="0"/>
       <element name="ext" type="sppfb:ExtAnyType" minOccurs="0"/>
      </sequence>
     </extension>
    </complexContent>
   </complexType>
   <annotation>
    <documentation>
     ---- Abstract Object and Element Type Definitions ----
    </documentation>
   </annotation>
   <complexType name="BasicObjType" abstract="true">
    <sequence>
     <element name="rant" type="sppfb:OrgIdType"/>
     <element name="rar" type="sppfb:OrgIdType"/>
     <element name="cDate" type="dateTime" minOccurs="0"/>
     <element name="mDate" type="dateTime" minOccurs="0"/>
     <element name="ext" type="sppfb:ExtAnyType" minOccurs="0"/>
    </sequence>
   </complexType>
   <complexType name="RegexParamType">
    <sequence>
     <element name="ere" type="sppfb:RegexType" default="^(.*)$"/>
     <element name="repl" type="sppfb:ReplType"/>
    </sequence>
   </complexType>
   <complexType name="IPAddrType">
    <sequence>
     <element name="addr" type="sppfb:AddrStringType"/>
     <element name="ext" type="sppfb:ExtAnyType" minOccurs="0"/>
    </sequence>
    <attribute name="type" type="sppfb:IPType" default="v4"/>
   </complexType>
   <complexType name="SedRecRefType">
    <sequence>
     <element name="sedKey" type="sppfb:ObjKeyType"/>
     <element name="priority" type="unsignedShort"/>
     <element name="ext" type="sppfb:ExtAnyType" minOccurs="0"/>
    </sequence>
   </complexType>
   <complexType name="SourceIdentType">
    <sequence>



Cartwright, et al.           Standards Track                   [Page 50]

RFC 7877                          SSPF                       August 2016


     <element name="sourceIdentRegex" type="sppfb:RegexType"/>
     <element name="sourceIdentScheme"
              type="sppfb:SourceIdentSchemeType"/>
     <element name="ext" type="sppfb:ExtAnyType" minOccurs="0"/>
    </sequence>
   </complexType>
   <complexType name="CORInfoType">
    <sequence>
     <element name="corClaim" type="boolean" default="true"/>
     <element name="cor" type="boolean" default="false" minOccurs="0"/>
     <element name="corDate" type="dateTime" minOccurs="0"/>
    </sequence>
   </complexType>
   <complexType name="SvcMenuType">
    <sequence>
     <element name="serverStatus" type="sppfb:ServerStatusType"/>
     <element name="majMinVersion" type="token" maxOccurs="unbounded"/>
     <element name="objURI" type="anyURI" maxOccurs="unbounded"/>
     <element name="extURI" type="anyURI"
              minOccurs="0" maxOccurs="unbounded"/>
    </sequence>
   </complexType>
   <complexType name="ExtAnyType">
    <sequence>
     <any namespace="##other" maxOccurs="unbounded"/>
    </sequence>
   </complexType>
   <simpleType name="FlagsType">
    <restriction base="token">
     <length value="1"/>
     <pattern value="[A-Z]|[a-z]|[0-9]"/>
    </restriction>
   </simpleType>
   <simpleType name="SvcType">
    <restriction base="token">
     <minLength value="1"/>
    </restriction>
   </simpleType>
   <simpleType name="RegexType">
    <restriction base="token">
     <minLength value="1"/>
    </restriction>
   </simpleType>
   <simpleType name="ReplType">
    <restriction base="token">
     <minLength value="1"/>
     <maxLength value="255"/>
    </restriction>



Cartwright, et al.           Standards Track                   [Page 51]

RFC 7877                          SSPF                       August 2016


   </simpleType>
   <simpleType name="OrgIdType">
    <restriction base="token"/>
   </simpleType>
   <simpleType name="ObjNameType">
    <restriction base="token">
     <minLength value="3"/>
     <maxLength value="80"/>
    </restriction>
   </simpleType>
   <simpleType name="TransIdType">
    <restriction base="token">
     <minLength value="3"/>
     <maxLength value="120"/>
    </restriction>
   </simpleType>
   <simpleType name="MinorVerType">
    <restriction base="unsignedLong"/>
   </simpleType>
   <simpleType name="AddrStringType">
    <restriction base="token">
     <minLength value="3"/>
     <maxLength value="45"/>
    </restriction>
   </simpleType>
   <simpleType name="IPType">
    <restriction base="token">
     <enumeration value="v4"/>
     <enumeration value="v6"/>
    </restriction>
   </simpleType>
   <simpleType name="SourceIdentSchemeType">
    <restriction base="token">
     <enumeration value="uri"/>
     <enumeration value="ip"/>
     <enumeration value="rootDomain"/>
    </restriction>
   </simpleType>
   <simpleType name="ServerStatusType">
    <restriction base="token">
     <enumeration value="inService"/>
     <enumeration value="outOfService"/>
    </restriction>
   </simpleType>
   <simpleType name="SedGrpOfferStatusType">
    <restriction base="token">
     <enumeration value="offered"/>
     <enumeration value="accepted"/>



Cartwright, et al.           Standards Track                   [Page 52]

RFC 7877                          SSPF                       August 2016


    </restriction>
   </simpleType>
   <simpleType name="NumberValType">
    <restriction base="token">
     <maxLength value="20"/>
     <pattern value="\+?\d\d*"/>
    </restriction>
   </simpleType>
   <simpleType name="NumberTypeEnum">
    <restriction base="token">
     <enumeration value="TN"/>
     <enumeration value="TNPrefix"/>
     <enumeration value="RN"/>
    </restriction>
   </simpleType>
   <simpleType name="SedFunctionType">
    <restriction base="token">
     <enumeration value="routing"/>
     <enumeration value="lookup"/>
    </restriction>
   </simpleType>
   <complexType name="NumberType">
    <sequence>
     <element name="value" type="sppfb:NumberValType"/>
     <element name="type" type="sppfb:NumberTypeEnum"/>
    </sequence>
   </complexType>
   <complexType name="NumberRangeType">
    <sequence>
     <element name="startRange" type="sppfb:NumberValType"/>
     <element name="endRange" type="sppfb:NumberValType"/>
    </sequence>
   </complexType>
  </schema>

















Cartwright, et al.           Standards Track                   [Page 53]

RFC 7877                          SSPF                       August 2016


13.  References

13.1.  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,
             <http://www.rfc-editor.org/info/rfc2119>.

  [RFC2277]  Alvestrand, H., "IETF Policy on Character Sets and
             Languages", BCP 18, RFC 2277, DOI 10.17487/RFC2277,
             January 1998, <http://www.rfc-editor.org/info/rfc2277>.

  [RFC3629]  Yergeau, F., "UTF-8, a transformation format of ISO
             10646", STD 63, RFC 3629, DOI 10.17487/RFC3629, November
             2003, <http://www.rfc-editor.org/info/rfc3629>.

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

  [RFC3986]  Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform
             Resource Identifier (URI): Generic Syntax", STD 66,
             RFC 3986, DOI 10.17487/RFC3986, January 2005,
             <http://www.rfc-editor.org/info/rfc3986>.

  [RFC5226]  Narten, T. and H. Alvestrand, "Guidelines for Writing an
             IANA Considerations Section in RFCs", BCP 26, RFC 5226,
             DOI 10.17487/RFC5226, May 2008,
             <http://www.rfc-editor.org/info/rfc5226>.

  [RFC5234]  Crocker, D., Ed. and P. Overell, "Augmented BNF for Syntax
             Specifications: ABNF", STD 68, RFC 5234,
             DOI 10.17487/RFC5234, January 2008,
             <http://www.rfc-editor.org/info/rfc5234>.

  [RFC7878]  Cartwright, K., Bhatia, V., Mule, J., and A. Mayrhofer,
             "Session Peering Provisioning (SPP) Protocol over SOAP",
             RFC 7878, DOI 10.17487/RFC7878, August 2016,
             <http://www.rfc-editor.org/info/rfc7878>.

  [W3C.REC-xml-20081126]
             Bray, T., Paoli, J., Sperberg-McQueen, C., Maler, E., and
             F. Yergeau, "Extensible Markup Language (XML) 1.0 (Fifth
             Edition)", World Wide Web Consortium Recommendation REC-
             xml-20081126, November 2008,
             <http://www.w3.org/TR/2008/REC-xml-20081126>.




Cartwright, et al.           Standards Track                   [Page 54]

RFC 7877                          SSPF                       August 2016


13.2.  Informative References

  [RFC2069]  Franks, J., Hallam-Baker, P., Hostetler, J., Leach, P.,
             Luotonen, A., Sink, E., and L. Stewart, "An Extension to
             HTTP : Digest Access Authentication", RFC 2069,
             DOI 10.17487/RFC2069, January 1997,
             <http://www.rfc-editor.org/info/rfc2069>.

  [RFC2781]  Hoffman, P. and F. Yergeau, "UTF-16, an encoding of ISO
             10646", RFC 2781, DOI 10.17487/RFC2781, February 2000,
             <http://www.rfc-editor.org/info/rfc2781>.

  [RFC2827]  Ferguson, P. and D. Senie, "Network Ingress Filtering:
             Defeating Denial of Service Attacks which employ IP Source
             Address Spoofing", BCP 38, RFC 2827, DOI 10.17487/RFC2827,
             May 2000, <http://www.rfc-editor.org/info/rfc2827>.

  [RFC3261]  Rosenberg, J., Schulzrinne, H., Camarillo, G., Johnston,
             A., Peterson, J., Sparks, R., Handley, M., and E.
             Schooler, "SIP: Session Initiation Protocol", RFC 3261,
             DOI 10.17487/RFC3261, June 2002,
             <http://www.rfc-editor.org/info/rfc3261>.

  [RFC3403]  Mealling, M., "Dynamic Delegation Discovery System (DDDS)
             Part Three: The Domain Name System (DNS) Database",
             RFC 3403, DOI 10.17487/RFC3403, October 2002,
             <http://www.rfc-editor.org/info/rfc3403>.

  [RFC4725]  Mayrhofer, A. and B. Hoeneisen, "ENUM Validation
             Architecture", RFC 4725, DOI 10.17487/RFC4725, November
             2006, <http://www.rfc-editor.org/info/rfc4725>.

  [RFC4732]  Handley, M., Ed., Rescorla, E., Ed., and IAB, "Internet
             Denial-of-Service Considerations", RFC 4732,
             DOI 10.17487/RFC4732, December 2006,
             <http://www.rfc-editor.org/info/rfc4732>.

  [RFC4949]  Shirey, R., "Internet Security Glossary, Version 2",
             FYI 36, RFC 4949, DOI 10.17487/RFC4949, August 2007,
             <http://www.rfc-editor.org/info/rfc4949>.

  [RFC5067]  Lind, S. and P. Pfautz, "Infrastructure ENUM
             Requirements", RFC 5067, DOI 10.17487/RFC5067, November
             2007, <http://www.rfc-editor.org/info/rfc5067>.







Cartwright, et al.           Standards Track                   [Page 55]

RFC 7877                          SSPF                       August 2016


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

  [RFC5486]  Malas, D., Ed. and D. Meyer, Ed., "Session Peering for
             Multimedia Interconnect (SPEERMINT) Terminology",
             RFC 5486, DOI 10.17487/RFC5486, March 2009,
             <http://www.rfc-editor.org/info/rfc5486>.

  [RFC5646]  Phillips, A., Ed. and M. Davis, Ed., "Tags for Identifying
             Languages", BCP 47, RFC 5646, DOI 10.17487/RFC5646,
             September 2009, <http://www.rfc-editor.org/info/rfc5646>.

  [RFC6116]  Bradner, S., Conroy, L., and K. Fujiwara, "The E.164 to
             Uniform Resource Identifiers (URI) Dynamic Delegation
             Discovery System (DDDS) Application (ENUM)", RFC 6116,
             DOI 10.17487/RFC6116, March 2011,
             <http://www.rfc-editor.org/info/rfc6116>.

  [RFC6461]  Channabasappa, S., Ed., "Data for Reachability of Inter-
             /Intra-NetworK SIP (DRINKS) Use Cases and Protocol
             Requirements", RFC 6461, DOI 10.17487/RFC6461, January
             2012, <http://www.rfc-editor.org/info/rfc6461>.

  [RFC7230]  Fielding, R., Ed. and J. Reschke, Ed., "Hypertext Transfer
             Protocol (HTTP/1.1): Message Syntax and Routing",
             RFC 7230, DOI 10.17487/RFC7230, June 2014,
             <http://www.rfc-editor.org/info/rfc7230>.

  [SOAPREF]  Gudgin, M., Hadley, M., Moreau, J., and H. Nielsen, "SOAP
             Version 1.2 Part 1: Messaging Framework", W3C REC REC-
             SOAP12-part1-20030624, June 2003,
             <http://www.w3.org/TR/soap12-part1/>.

  [Unicode6.1]
             The Unicode Consortium, "The Unicode Standard, Version
             6.1.0", (Mountain View, CA: The Unicode Consortium,
             2012. ISBN 978-1-936213-02-3),
             <http://unicode.org/versions/Unicode6.1.0/>.











Cartwright, et al.           Standards Track                   [Page 56]

RFC 7877                          SSPF                       August 2016


Acknowledgements

  This document is a result of various discussions held in the DRINKS
  working group and within the DRINKS protocol design team, with
  contributions from the following individuals, in alphabetical order:
  Syed Ali, Jeremy Barkan, Vikas Bhatia, Sumanth Channabasappa, Lisa
  Dusseault, Deborah A.  Guyton, Otmar Lendl, Manjul Maharishi, Mickael
  Marrache, Alexander Mayrhofer, Samuel Melloul, David Schwartz, and
  Richard Shockey.

Authors' Addresses

  Kenneth Cartwright
  TNS
  1939 Roland Clarke Place
  Reston, VA  20191
  United States

  Email: [email protected]


  Vikas Bhatia
  TNS
  1939 Roland Clarke Place
  Reston, VA  20191
  United States

  Email: [email protected]


  Syed Wasim Ali
  NeuStar
  46000 Center Oak Plaza
  Sterling, VA  20166
  United States

  Email: [email protected]


  David Schwartz
  XConnect
  316 Regents Park Road
  London  N3 2XJ
  United Kingdom

  Email: [email protected]





Cartwright, et al.           Standards Track                   [Page 57]