Internet Engineering Task Force (IETF)                    F. Jounay, Ed.Request for Comments: 7338                                     Orange CHCategory: Informational                                   Y. Kamite, Ed.ISSN: 2070-1721                                       NTT Communications                                                                G. Heron                                                           Cisco Systems                                                                M. Bocci                                                          Alcatel-Lucent                                                          September 2014     Requirements and Framework for Point-to-Multipoint Pseudowires                   over MPLS Packet Switched NetworksAbstract   This document presents a set of requirements and a framework for   providing a point-to-multipoint pseudowire (PW) over MPLS Packet   Switched Networks.  The requirements identified in this document are   related to architecture, signaling, and maintenance aspects of point-   to-multipoint PW operation.  They are proposed as guidelines for the   standardization of such mechanisms.  Among other potential   applications, point-to-multipoint PWs can be used to optimize the   support of multicast Layer 2 services (Virtual Private LAN Service   and Virtual Private Multicast Service).Status of This Memo   This document is not an Internet Standards Track specification; it is   published for informational purposes.   This document is a product of the Internet Engineering Task Force   (IETF).  It represents the consensus of the IETF community.  It has   received public review and has been approved for publication by the   Internet Engineering Steering Group (IESG).  Not all documents   approved by the IESG are a candidate for any level of Internet   Standard; see Section 2 of RFC 5741.   Information about the current status of this document, any errata,   and how to provide feedback on it may be obtained at   http://www.rfc-editor.org/info/rfc7338.Jounay, et al.                Informational                     [Page 1]RFC 7338                  P2MP PW Requirements            September 2014Copyright Notice   Copyright (c) 2014 IETF Trust and the persons identified as the   document authors.  All rights reserved.   This document is subject to BCP 78 and the IETF Trust's Legal   Provisions Relating to IETF Documents   (http://trustee.ietf.org/license-info) in effect on the date of   publication of this document.  Please review these documents   carefully, as they describe your rights and restrictions with respect   to this document.  Code Components extracted from this document must   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.   This document may contain material from IETF Documents or IETF   Contributions published or made publicly available before November   10, 2008.  The person(s) controlling the copyright in some of this   material may not have granted the IETF Trust the right to allow   modifications of such material outside the IETF Standards Process.   Without obtaining an adequate license from the person(s) controlling   the copyright in such materials, this document may not be modified   outside the IETF Standards Process, and derivative works of it may   not be created outside the IETF Standards Process, except to format   it for publication as an RFC or to translate it into languages other   than English.Jounay, et al.                Informational                     [Page 2]RFC 7338                  P2MP PW Requirements            September 2014Table of Contents   1. Introduction ....................................................3      1.1. Problem Statement ..........................................3      1.2. Scope of This Document .....................................4      1.3. Conventions Used in This Document ..........................4   2. Definitions .....................................................5      2.1. Acronyms ...................................................5      2.2. Terminology ................................................5   3. P2MP PW Requirements ............................................6      3.1. Reference Model ............................................6      3.2. P2MP PW and Underlying Layer ...............................7      3.3. P2MP PW Construction .......................................9      3.4. P2MP PW Signaling Requirements ............................10           3.4.1. P2MP PW Identifier .................................10           3.4.2. PW Type Mismatch ...................................10           3.4.3. Interface Parameters Sub-TLV .......................10           3.4.4. Leaf Grafting/Pruning ..............................10           3.4.5. Failure Detection and Reporting ....................11           3.4.6. Protection and Restoration .........................11           3.4.7. Scalability ........................................13   4. Backward Compatibility .........................................13   5. Security Considerations ........................................13   6. References .....................................................14      6.1. Normative References ......................................14      6.2. Informative References ....................................14   7. Acknowledgments ................................................15   8. Contributors ...................................................161.  Introduction1.1.  Problem Statement   As defined in the pseudowire architecture [RFC3985], a pseudowire   (PW) is a mechanism that emulates the essential attributes of a   telecommunications service (such as a T1 leased line or Frame Relay)   over an IP or MPLS Packet Switched Network (PSN).  It provides a   single service that is perceived by its user as an unshared link or   circuit of the chosen service.  A pseudowire is used to transport   Layer 1 or Layer 2 traffic (e.g., Ethernet, Time-Division   Multiplexing (TDM), ATM, and Frame Relay) over a Layer 3 PSN.   Pseudowire Emulation Edge-to-Edge (PWE3) operates "edge to edge" to   provide the required connectivity between the two endpoints of the   PW.   The point-to-multipoint (P2MP) topology described in [VPMS-REQS] and   required to provide P2MP Layer 2 VPN service can be achieved using   one or more P2MP PWs.  The use of PW encapsulation enables P2MPJounay, et al.                Informational                     [Page 3]RFC 7338                  P2MP PW Requirements            September 2014   services to transport Layer 1 or Layer 2 data.  This could be   achieved using a set of point-to-point PWs, with traffic replication   at the Root Provider Edge (PE), but at the cost of bandwidth   efficiency, as duplicate traffic would be carried multiple times on   shared links.   This document defines the requirements for a point-to-multipoint PW   (P2MP PW).  A P2MP PW is a mechanism that emulates the essential   attributes of a P2MP telecommunications service such as a P2MP ATM   Virtual Circuit over a Packet Switched Network.   The required functions of P2MP PWs include encapsulating service-   specific Protocol Data Units (PDUs) arriving at an ingress Attachment   Circuit (AC), carrying them across a tunnel to one or more egress   ACs, managing their timing and order, and any other operations   required to emulate the behavior and characteristics of the service   as faithfully as possible.1.2.  Scope of This Document   The document describes the general architecture of P2MP PW with a   reference model, mentions the notion of data encapsulation, and   outlines specific requirements for the setup and maintenance of a   P2MP PW.  In this document, the requirements focus on the Single-   Segment PW model.  The requirements for realizing P2MP PW in the   Multi-Segment PW model [RFC5254] are left for further study.  This   document refers to [RFC3916] for other aspects of P2MP PW   implementation, such as "Packet Processing" (Section 4 of that   document) and "Faithfulness of Emulated Services" (Section 7 of that   document).1.3.  Conventions Used in This Document   Although this is a requirements specification not a protocol   specification, the key words "MUST", "MUST NOT", "REQUIRED", "SHALL",   "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and   "OPTIONAL" in this document are to be interpreted to apply to   protocol solutions designed to meet these requirements as described   in [RFC2119].Jounay, et al.                Informational                     [Page 4]RFC 7338                  P2MP PW Requirements            September 20142.  Definitions2.1.  Acronyms   P2P:   Point-to-Point   P2MP:  Point-to-Multipoint   PW:    Pseudowire   PSN:   Packet Switched Network   SS-PW: Single-Segment Pseudowire2.2.  Terminology   This document uses terminology described in [RFC5659].  It also   introduces additional terms needed in the context of P2MP PW.   P2MP PW (also referred to as PW tree):      Point-to-Multipoint Pseudowire.  A PW attached to a source      Customer Edge (CE) used to distribute Layer 1 or Layer 2 traffic      to a set of one or more receiver CEs.  The P2MP PW is      unidirectional (i.e., carrying traffic from Root PE to Leaf PEs)      and optionally supports a return path.   P2MP SS-PW:      Point-to-Multipoint Single-Segment Pseudowire.  A single-segment      P2MP PW set up between the Root PE attached to the source CE and      the Leaf PEs attached to the receiver CEs.  The P2MP SS-PW uses      P2MP Label Switched Paths (LSPs) as PSN tunnels.   Root PE:      P2MP PW Root Provider Edge.  The PE attached to the traffic source      CE for the P2MP PW via an Attachment Circuit (AC).   Leaf PE:      P2MP PW Leaf Provider Edge.  A PE attached to a set of one or more      traffic receiver CEs, via ACs.  The Leaf PE replicates traffic to      the CEs based on its Forwarder function [RFC3985].   P2MP PSN Tunnel:      In the P2MP SS-PW topology, the PSN tunnel is a general term      indicating a virtual P2MP connection between the Root PE and the      Leaf PEs.  A P2MP tunnel may potentially carry multiple P2MP PWs      inside (aggregation).  This document uses terminology from the      document describing the MPLS multicast architecture [RFC5332] for      MPLS PSN.Jounay, et al.                Informational                     [Page 5]RFC 7338                  P2MP PW Requirements            September 20143.  P2MP PW Requirements3.1.  Reference Model   As per the definition in [RFC3985], a pseudowire (PW) both originates   and terminates on the edge of the same packet switched network (PSN).   The PW label is unchanged between the originating and terminating   Provider Edges (PEs).  This is also known as a single-segment   pseudowire (SS-PW) -- the most fundamental network model of PWE3.   A P2MP PW can be defined as point-to-multipoint connectivity from a   Root PE connected to a traffic source CE to one or more Leaf PEs   connected to traffic receiver CEs.  It is considered to be an   extended architecture of the existing P2P SS-PW technology.   Figure 1 describes the P2MP PW reference model that is derived from   [RFC3985] to support P2MP emulated services.                  |<-------------P2MP PW------------->|          Native  |                                   |  Native   ROOT   Service |    |<----P2MP PSN tunnel --->|    |  Service  LEAF    V     (AC)    V    V                         V    V   (AC)      V            |     +----+         +-----+         +----+     |            |     |PE1 |         |  P  |=========|PE2 |AC2  |     +----+            |     |    |         |   ......PW1.......>|---------->|CE2 |            |     |    |         |   . |=========|    |     |     +----+            |     |    |         |   . |         +----+     |            |     |    |=========|   . |                    |            |     |    |         |   . |         +----+     |   +----+   | AC1 |    |         |   . |=========|PE3 |AC3  |     +----+   |CE1 |-------->|........PW1.............PW1.......>|---------->|CE3 |   +----+   |     |    |         |   . |=========|    |     |     +----+            |     |    |         |   . |         +----+     |            |     |    |=========|   . |                    |            |     |    |         |   . |         +----+AC4  |     +----+            |     |    |         |   . |=========|PE4 |---------->|CE4 |            |     |    |         |   ......PW1.......>|     |     +----+            |     |    |         |     |=========|    |AC5  |     +----+            |     |    |         |     |         |    |---------->|CE5 |            |     +----+         +-----+         +----+     |     +----+                    Figure 1: P2MP PW Reference Model   This architecture applies to the case where a P2MP PSN tunnel extends   between edge nodes of a single PSN domain to transport a   unidirectional P2MP PW with endpoints at these edge nodes.  In this   model, a single copy of each PW packet is sent over the PW on the   P2MP PSN tunnel and is received by all Leaf PEs due to the P2MPJounay, et al.                Informational                     [Page 6]RFC 7338                  P2MP PW Requirements            September 2014   nature of the PSN tunnel.  The P2MP PW SHOULD be traffic optimized,   i.e., only one copy of a P2MP PW packet or PSN tunnel (underlying   layer) packet is sent on any single link along the P2MP path.  P   routers participate in P2MP PSN tunnel operation but not in the   signaling of P2MP PWs.   The Reference Model outlines the basic pieces of a P2MP PW.  However,   several levels of replication need to be considered when designing a   P2MP PW solution:   -  Ingress PE replication to CEs: traffic is replicated to a set of      local receiver CEs   -  P router replication in the core: traffic is replicated by means      of a P2MP PSN tunnel (P2MP LSP)   -  Egress PE replication to CEs: traffic is replicated to local      receiver CEs   Theoretically, it is also possible to consider Ingress PE replication   in the core; that is, all traffic is replicated to a set of P2P PSN   transport tunnels at ingress, not using P router replication at all.   However, this approach may lead to duplicate copies of each PW packet   being sent over the same physical link, specifically in the case   where multiple PSN tunnels transit that physical link.  Hence, this   approach is not preferred.   Specific operations that MUST be performed at the PE on the native   data units are not described here since the required pre-processing   (Forwarder (FWRD) and Native Service Processing (NSP)) defined in   Section 4.2 of [RFC3985] is also applicable to P2MP PW.   P2MP PWs are generally unidirectional, but a Root PE may need to   receive unidirectional P2P return traffic from any Leaf PE.  For that   purpose, the P2MP PW solution MAY support an optional return path   from each Leaf PE to the Root PE.3.2.  P2MP PW and Underlying Layer   The definition of MPLS multicast encapsulation [RFC5332] specifies   the procedure to carry MPLS packets that are to be replicated and a   copy of the packet sent to each of the specified next hops.  This   notion is also applicable to a P2MP PW packet carried by a P2MP PSN   tunnel.   To be more precise, a P2MP PSN tunnel corresponds to a "point-to-   multipoint data link or tunnel" described in Section 3 of [RFC5332].Jounay, et al.                Informational                     [Page 7]RFC 7338                  P2MP PW Requirements            September 2014   Similarly, P2MP PW labels correspond to "the top labels (before   applying the data link or tunnel encapsulation) of all MPLS packets   that are transmitted on a particular point-to-multipoint data link or   tunnel".   In the P2MP PW architecture using the SS-PW network model, the PW-PDU   [RFC3985] is replicated by the underlying P2MP PSN tunnel layer.   Note that the PW label is unchanged, and hidden in switching, by the   transit P routers.   In a solution, a P2MP PW MUST be supported over a single P2MP PSN   tunnel as the underlying layer of traffic distribution.  Figure 2   gives an example of P2MP PW topology relying on a single P2MP LSP.   The PW tree is composed of one Root PE (i1) and several Leaf PEs (e1,   e2, e3, e4).   The mechanisms for establishing the PSN tunnel are outside the scope   of this document, as long as they enable the essential attributes of   the service to be emulated.                                i1                                /                               / \                              /   \                             /     \                            /\      \                           /  \      \                          /    \      \                         /      \    / \                        e1      e2  e3 e4          Figure 2: Example of P2MP Underlying Layer for P2MP PW   A single P2MP PSN tunnel MUST be able to serve the traffic from more   than one P2MP PW in an aggregated way, i.e., multiplexing.   A P2MP PW solution MAY support different P2MP PSN tunneling   technology (e.g., MPLS over GRE [RFC4023] or P2MP MPLS LSP) or   different setup protocols (e.g., multipoint extensions for LDP (mLDP)   [RFC6388] and P2MP RSVP-TE [RFC4875]).   The P2MP LSP associated to the P2MP PW can be selected either by user   configuration or by dynamically using a multiplexing/demultiplexing   mechanism.   The P2MP PW multiplexing SHOULD be used based on the overlap rate   between P2MP LSP and P2MP PW.  As an example, an existing P2MP LSP   may attach more leaves than the ones defined as Leaf PEs for a givenJounay, et al.                Informational                     [Page 8]RFC 7338                  P2MP PW Requirements            September 2014   P2MP PW.  It may be attractive to reuse it to minimize new   configuration, but using this P2MP LSP would cause non-Leaf PEs   (i.e., not part of the P2MP PW) to receive unwanted traffic.   Note: no special configuration is needed for non-Leaf PEs to drop   that unwanted traffic because they do not have forwarding information   entries unless they process the setup operation for corresponding   P2MP PWs (e.g., signaling).   The operator SHOULD determine whether it is acceptable to partially   multiplex the P2MP PW onto a P2MP LSP, and a minimum congruency rate   may be defined to enable the Root PE to make this determination.  The   congruency rate SHOULD take into account several items, including:   -  the amount of overlap between the Leaf PEs of the P2MP PW and the      existing egress PE routers of the P2MP LSP.  If there is a      complete overlap, the congruency is perfect and the rate is 100%.   -  the impact on other traffic (e.g., from other VPNs) supported over      the P2MP LSP.   With this procedure, a P2MP PW is nested within a P2MP LSP.  This   allows multiplexing several PWs over a common P2MP LSP.  Prior to the   P2MP PW signaling phase, the Root PE determines which P2MP LSP will   be used for this P2MP PW.  The PSN tunnel can be an existing PSN   tunnel or the Root PE can create a new P2MP PSN tunnel.  Note that   the ingress PE may modify or re-create an existing P2MP PSN tunnel in   order to add one or more leaf PEs to enable it to transport the P2MP   PW.3.3.  P2MP PW Construction   [RFC5332] introduces two approaches to assigning MPLS labels (meaning   PW labels in the P2MP PW context): Upstream-Assigned [RFC5331] and   Downstream-Assigned.  However, it is out of scope of this document   which one should be used in PW construction.  It is left to the   specification of the solution.   The following requirements apply to the establishment of P2MP PWs:   -  PE nodes MUST be configurable with the P2MP PW identifiers and      ACs.   -  A discovery mechanism SHOULD allow the Root PE to discover the      Leaf PEs, or vice versa.Jounay, et al.                Informational                     [Page 9]RFC 7338                  P2MP PW Requirements            September 2014   -  Solutions SHOULD allow single-sided operation at the Root PE for      the selection of some AC(s) at the Leaf PE(s) to be attached to      the PW tree so that the Root PE controls the leaf attachment.   -  The Root PE SHOULD support a method to be informed about whether a      Leaf PE has successfully attached to the PW tree.3.4.  P2MP PW Signaling Requirements3.4.1.  P2MP PW Identifier   The P2MP PW MUST be uniquely identified.  This unique P2MP PW   identifier MUST be used for all signaling procedures related to this   PW (PW setup, monitoring, etc.).3.4.2.  PW Type Mismatch   The Root PE and Leaf PEs of a P2MP PW MUST be configured with the   same PW type as defined in [RFC4446] for P2P PW.  In case of a type   mismatch, a PE SHOULD abort attempts to attach the Leaf PE to the   P2MP PW.3.4.3.  Interface Parameters Sub-TLV   Some interface parameters [RFC4446] related to the AC capability have   been defined according to the PW type and are signaled during the PW   setup.   Where applicable, a solution is REQUIRED to ascertain whether the AC   at the Leaf PE is capable of supporting traffic coming from the AC at   the Root PE.   In case of a mismatch, the passive PE (Root or Leaf PE, depending on   the signaling process) SHOULD support mechanisms to reject attempts   to attach the Leaf PE to the P2MP PW.3.4.4.  Leaf Grafting/Pruning   Once the PW tree is established, the solution MUST allow the addition   or removal of a Leaf PE, or a subset of leaves to/from the existing   tree, without any impact on the PW tree (data and control planes) for   the remaining Leaf PEs.   The addition or removal of a Leaf PE MUST also allow the P2MP PSN   tunnel to be updated accordingly.  This may cause the P2MP PSN tunnel   to add or remove the corresponding Leaf PE.Jounay, et al.                Informational                    [Page 10]RFC 7338                  P2MP PW Requirements            September 20143.4.5.  Failure Detection and Reporting   Since the underlying layer has an end-to-end P2MP topology between   the Root PE and the Leaf PEs, the failure reporting and processing   procedures are implemented only on the edge nodes.   Failure events may cause one or more Leaf PEs to become detached from   the PW tree.  These events MUST be reported to the Root PE, using   appropriate out-of-band or in-band Operations, Administration, and   Maintenance (OAM) messages for monitoring.   It MUST be possible for the operator to choose the out-of-band or in-   band monitoring tools or both to monitor the Leaf PE status.  For   management purposes, the solution SHOULD allow the Root PE to be   informed of Leaf PEs' failure.   Based on these failure notifications, solutions MUST allow the Root   PE to update the remaining leaves of the PW tree.   -  A solution MUST support an in-band status notification mechanism      to detect failures: unidirectional point-to-multipoint traffic      failure.  This MUST be realized by enhancing existing unicast PW      methods, such as Virtual Circuit Connectivity Verification (VCCV)      for seamless and familiar operation as defined in [RFC5085].   -  In case of failure, it MUST correctly report which Leaf PEs are      affected.  This MUST be realized by enhancing existing PW methods,      such as LDP Status Notification.  The notification message SHOULD      include the type of fault (P2MP PW, AC, or PSN tunnel).   -  A Leaf PE MAY be notified of the status of the Root PE's AC.   -  A solution MUST support OAM message mapping [RFC6310] at the Root      PE and Leaf PE if a failure is detected on the source CE.3.4.6.  Protection and Restoration   It is assumed that if recovery procedures are required, the P2MP PSN   tunnel will support standard MPLS-based recovery techniques.  In that   case, a mechanism SHOULD be implemented to avoid race conditions   between recovery at the PSN level and recovery at the PW level.   An alternative protection scheme MAY rely on the PW layer.   Leaf PEs MAY be protected via a P2MP PW redundancy mechanism.  In the   example depicted below, a standby P2MP PW is used to protect the   active P2MP PW.  In that protection scheme, the AC at the Root PE   MUST serve both P2MP PWs.  In this scenario, the criteria forJounay, et al.                Informational                    [Page 11]RFC 7338                  P2MP PW Requirements            September 2014   switching over SHOULD be defined, e.g., failure of one or all leaves   of the active P2MP PW will trigger switchover of the whole P2MP PW.                                     CE1                                      |         ROOT           active       PE1    standby                        P2MP PW  .../  \....P2MP PW                                /           \                              P2            P3                             / \           / \                            /   \         /   \                           /     \       /     \         LEAF            PE4    PE5    PE6    PE7                          |      |      |      |                          |       \    /       |                           \        CE2       /                            \                /                              ------CE3-----      Figure 3: Example of P2MP PW Redundancy for Protecting Leaf PEs   Note that some of the nodes/links in this figure can be physically   shared; this depends on the service provider policy of network   redundancy.   The Root PE MAY be protected via a P2MP PW redundancy mechanism.  In   the example depicted below, a standby P2MP PW is used to protect the   active P2MP.  A single AC at the Leaf PE MUST be used to attach the   CE to the primary and the standby P2MP PW.  The Leaf PE MUST support   protection mechanisms in order to select the active P2MP PW.                                     CE1                                    /  \                                   |    |               ROOT     active    PE1  PE2   standby                        P2MP PW1   |    |    P2MP PW2                                   |    |                                   P2  P3                                  /  \/  \                                 /   /\   \                                /   /  \   \                               /   /    \   \               LEAF            PE4        PE5                                |          |                               CE2        CE3      Figure 4: Example of P2MP PW Redundancy for Protecting Root PEsJounay, et al.                Informational                    [Page 12]RFC 7338                  P2MP PW Requirements            September 20143.4.7.  Scalability   The solution SHOULD scale at worst linearly for message size, memory   requirements, and processing requirements, with the number of Leaf   PEs.   Increasing the number of P2MP PWs between a Root PE and a given set   of Leaf PEs SHOULD NOT cause the P router to increase the number of   entries in its forwarding table by the same or greater proportion.   Multiplexing P2MP PWs to P2MP PSN tunnels achieves this.4.  Backward Compatibility   Solutions MUST be backward compatible with current PW standards.   Solutions SHOULD utilize existing capability advertisement and   negotiation procedures for the PEs implementing P2MP PW endpoints.   The implementation of OAM mechanisms also implies the advertisement   of PE capabilities to support specific OAM features.  The solution   MAY allow advertising P2MP PW OAM capabilities.  A solution MUST NOT   allow a P2MP PW to be established to PEs that do not support P2MP PW   functionality.  It MUST have a mechanism to report an error for   incompatible PEs.   In some cases, upstream traffic is needed from downstream CEs to   upstream CEs.  The P2MP PW solution SHOULD allow a return path (i.e.,   from the Leaf PE to the Root PE) that provides upstream connectivity.   In particular, the same ACs MAY be shared between the downstream and   upstream directions.  For downstream, a CE receives traffic   originated by the Root PE over its AC.  For upstream, the CE MAY also   send traffic destined to the same Root PE over the same AC.5.  Security Considerations   The security requirements common to PW are raised in Section 11 of   [RFC3916].  P2MP PW is a variant of the initial P2P PW definition,   and those requirements (and the security considerations from   [RFC3985]) also apply.  The security considerations from [RFC5920]   and [RFC6941] also apply to the IP/MPLS and MPLS-TP deployment   scenarios, respectively.   Some issues specifically due to P2MP topology need to be addressed in   the definition of the solution:   -  The solution SHOULD provide means to protect the traffic delivered      to receivers (Integrity, Confidentiality, Endpoint      Authentication).Jounay, et al.                Informational                    [Page 13]RFC 7338                  P2MP PW Requirements            September 2014   -  The solution SHOULD support means to protect the P2MP PW as a      whole against attacks that would lead to any kind of denial of      service.   Specifically, safeguard mechanisms should be considered to avoid any   negative impact on the whole PW tree when any one receiver or any   group of receivers is attacked.  Safeguard mechanisms for both the   data plane and the control plane need to be considered.6.  References6.1.  Normative References   [RFC2119]   Bradner, S., "Key words for use in RFCs to Indicate               Requirement Levels", BCP 14, RFC 2119, March 1997.   [RFC3916]   Xiao, X., Ed., McPherson, D., Ed., and P. Pate, Ed.,               "Requirements for Pseudo-Wire Emulation Edge-to-Edge               (PWE3)", RFC 3916, September 2004.   [RFC3985]   Bryant, S., Ed., and P. Pate, Ed., "Pseudo Wire Emulation               Edge-to-Edge (PWE3) Architecture", RFC 3985, March 2005.   [RFC4446]   Martini, L., "IANA Allocations for Pseudowire Edge to               Edge Emulation (PWE3)", BCP 116, RFC 4446, April 2006.   [RFC5332]   Eckert, T., Rosen, E., Ed., Aggarwal, R., and Y. Rekhter,               "MPLS Multicast Encapsulations", RFC 5332, August 2008.   [RFC5659]   Bocci, M. and S. Bryant, "An Architecture for Multi-               Segment Pseudowire Emulation Edge-to-Edge", RFC 5659,               October 2009.   [RFC6310]   Aissaoui, M., Busschbach, P., Martini, L., Morrow, M.,               Nadeau, T., and Y(J). Stein, "Pseudowire (PW) Operations,               Administration, and Maintenance (OAM) Message Mapping",               RFC 6310, July 2011.6.2.  Informative References   [RFC4023]   Worster, T., Rekhter, Y., and E. Rosen, Ed.,               "Encapsulating MPLS in IP or Generic Routing               Encapsulation (GRE)", RFC 4023, March 2005.   [RFC4461]   Yasukawa, S., Ed., "Signaling Requirements for Point-to-               Multipoint Traffic-Engineered MPLS Label Switched Paths               (LSPs)", RFC 4461, April 2006.Jounay, et al.                Informational                    [Page 14]RFC 7338                  P2MP PW Requirements            September 2014   [RFC4875]   Aggarwal, R., Ed., Papadimitriou, D., Ed., and S.               Yasukawa, Ed., "Extensions to Resource Reservation               Protocol - Traffic Engineering (RSVP-TE) for Point-to-               Multipoint TE Label Switched Paths (LSPs)", RFC 4875, May               2007.   [RFC5085]   Nadeau, T., Ed., and C. Pignataro, Ed., "Pseudowire               Virtual Circuit Connectivity Verification (VCCV): A               Control Channel for Pseudowires", RFC 5085, December               2007.   [RFC5254]   Bitar, N., Ed., Bocci, M., Ed., and L. Martini, Ed.,               "Requirements for Multi-Segment Pseudowire Emulation               Edge-to-Edge (PWE3)", RFC 5254, October 2008.   [RFC5331]   Aggarwal, R., Rekhter, Y., and E. Rosen, "MPLS Upstream               Label Assignment and Context-Specific Label Space", RFC               5331, August 2008.   [RFC5920]   Fang, L., Ed., "Security Framework for MPLS and GMPLS               Networks", RFC 5920, July 2010.   [RFC6388]   Wijnands, IJ., Ed., Minei, I., Ed., Kompella, K., and B.               Thomas, "Label Distribution Protocol Extensions for               Point-to-Multipoint and Multipoint-to-Multipoint Label               Switched Paths", RFC 6388, November 2011.   [RFC6941]   Fang, L., Ed., Niven-Jenkins, B., Ed., Mansfield, S.,               Ed., and R. Graveman, Ed., "MPLS Transport Profile               (MPLS-TP) Security Framework", RFC 6941, April 2013.   [VPMS-REQS] Kamite, Y., Jounay, F., Niven-Jenkins, B., Brungard, D.,               and L. Jin, "Framework and Requirements for Virtual               Private Multicast Service (VPMS)", Work in Progress,               October 2012.7.  Acknowledgments   The authors thank the following people: the authors of [RFC4461]   since the structure and content of this document were, for some   sections, largely inspired by [RFC4461]; JL. Le Roux and A. Cauvin   for the discussions, comments, and support; Adrian Farrel for his   Routing Area Director review; and IESG reviewers.Jounay, et al.                Informational                    [Page 15]RFC 7338                  P2MP PW Requirements            September 20148.  Contributors   Philippe Niger   France Telecom   2, avenue Pierre-Marzin   22307 Lannion Cedex   France   EMail: philippe.niger@orange-ftgroup.com   Luca Martini   Cisco Systems, Inc.   9155 East Nichols Avenue, Suite 400   Englewood, CO  80112   US   EMail: lmartini@cisco.com   Lei Wang   Telenor   Snaroyveien 30   Fornebu 1331   Norway   EMail: lei.wang@telenor.com   Rahul Aggarwal   Juniper Networks   1194 North Mathilda Ave.   Sunnyvale, CA  94089   US   EMail: rahul@juniper.net   Simon Delord   Telstra   380 Flinders Lane   Melbourne   Australia   EMail: simon.delord@gmail.comJounay, et al.                Informational                    [Page 16]RFC 7338                  P2MP PW Requirements            September 2014   Martin Vigoureux   Alcatel-Lucent France   Route de Villejust   91620 Nozay   France   EMail: martin.vigoureux@alcatel-lucent.fr   Lizhong Jin   ZTE Corporation   889, Bibo Road   Shanghai, 201203   China   EMail: lizho.jin@gmail.comJounay, et al.                Informational                    [Page 17]RFC 7338                  P2MP PW Requirements            September 2014Authors' Addresses   Frederic Jounay (editor)   Orange CH   4 rue caudray 1020 Renens   Switzerland   EMail: frederic.jounay@orange.ch   Yuji Kamite (editor)   NTT Communications Corporation   1-1-6 Uchisaiwai-cho, Chiyoda-ku   Tokyo 100-8019   Japan   EMail: y.kamite@ntt.com   Giles Heron   Cisco Systems, Inc.   9 New Square   Bedfont Lakes   Feltham   Middlesex   TW14 8HA   United Kingdom   EMail: giheron@cisco.com   Matthew Bocci   Alcatel-Lucent Telecom Ltd   Voyager Place   Shoppenhangers Road   Maidenhead   Berks   United Kingdom   EMail: Matthew.Bocci@alcatel-lucent.comJounay, et al.                Informational                    [Page 18]