Pseudowire Emulation Edge to Edge (pwe3)

In addition to this official charter maintained by the IETF Secretariat, there is additional information about this working group on the Web at:

       MPLS Architectural Considerations for a Transport Profile (PDF)

Last Modified: 2008-09-11

Additional information is available at tools.ietf.org/wg/pwe3

Chair(s):

  • Stewart Bryant <stbryant@cisco.com>

  • Matthew Bocci <matthew.bocci@alcatel-lucent.com>

    Internet Area Director(s):

  • Jari Arkko <jari.arkko@piuha.net>
  • Mark Townsley <townsley@cisco.com>

    Internet Area Advisor:

  • Mark Townsley <townsley@cisco.com>

    Technical Advisor(s):

  • David Black <black_david@emc.com>

    Secretary(ies):

  • David Sinicrope <david.sinicrope@ericsson.com>

    Mailing Lists:

    General Discussion: pwe3@ietf.org
    To Subscribe: pwe3-request@ietf.org
    In Body: subscribe your_email_address
    Archive: http://www.ietf.org/mail-archive/web/pwe3/index.html

    Description of Working Group:

    Network transport service providers and their users are
    seeking to rationalize their networks by migrating their
    existing services and platforms onto IP or MPLS enabled
    IP packet switched networks (PSN). This migration requires
    communications services that can emulate the essential
    properties of traditional communications links over a PSN.
    Some service providers wish to use MPLS technology to
    replace existing transport network infrastructure, relying
    upon pseudowire technology is an integral component of
    these network convergence architectures.

    Pseudowire Emulation Edge to Edge (PWE3) will specify the
    encapsulation, transport, control, management, interworking
    and security of services emulated over IETF-specified PSNs.

    A pseudowire emulates a point-to-point or point-to-multipoint
    link, and provides a single service which is perceived by
    its user as an unshared link or circuit of the chosen
    service. It is not intended that an emulated service will
    be indistinguishable from the service that is being emulated.
    The emulation need only be sufficient for the satisfactory
    operation of the service. Emulation necessarily involves a
    degree of cost-performance trade-off. In some cases it may
    be necessary to design more than one emulation mechanism in
    order to resolve these design conflicts. All emulated service
    definitions must include an applicability statement describing
    the faithfulness of the emulation.

    Switching, multiplexing, modification or other operation on
    the traditional service, unless required as part of the
    emulation, is out of the scope of the PWE3 WG.

    PWE3 will make use of existing IETF-specified mechanisms
    unless there are technical reasons why the existing mechanisms
    are insufficient or unnecessary.

    PWE3 operates "edge to edge" and will not exert control on
    the underlying PSN, other than to use any existing QoS or
    path control mechanism to provide the required connectivity
    between the endpoints of the PW.

    PWE3 will co-ordinate this with the AVT and TICTOC WGs.
    Where AVT or TICTOC require extensions to PWs to support
    time or frequency transfer this work will be undertaken by
    the PWE3 WG in co-ordination with the these WGs.

    A PW operating over a shared PSN does not necessarily have
    the same intrinsic security as a dedicated, purpose built,
    network. In some cases this is satisfactory, while in other
    cases it will be necessary to enhance the security of the PW
    to emulate the intrinsic security of the emulated service.
    PW specifications MUST include a description of how they
    are to be operated over a shared PSN with adequate security.
    PWE3 will work with the MPLS, L2VPN and other relevant WGs
    for definitions of common solutions for the secure operation
    of pseudowires.

    Whilst a service provider may traffic engineer their network
    in such a way that PW traffic will not cause significant
    congestion, a PW deployed by an end-user may cause
    congestion of the underlying PSN. Suitable congestion
    avoidance mechanisms are therefore needed to protect the
    Internet from the unconstrained deployment of PWs.  Congestion
    avoidance may be more difficult with P2MP pseudowires than
    P2P pseudowires. The WG will consider both cases.

    PWE3 will work closely with the L2VPN WG to ensure a clear
    demarcation is defined for where PWE3 stops and L2VPN starts,
    in particular in defining point-multipoint (P2MP) PWs.

    PWE3 will work with MPLS and L2VPN to enhance the OAM suite
    for transport applications. PWE3 will coordinate very closely
    with any WG that is responsible for protocols which PWE3
    intends to extend (e.g., the MPLS WG for LDP), as well as
    foster interaction with WGs that intend to extend PWE3
    protocols.

    The IETF PWE3 WG is the design authority for pseudo-wire
    over IP/MPLS PSN technology. An entity or individual that
    wishes to propose extensions or changes to this technology
    must bring the corresponding proposals to the PWE3 WG that
    would treat them via a process similar to one described in
    RFC 4929 for the MPLS/GMPLS change process.

    WG Objectives:

    Specify the following PW types:

    Most of the initial specific PW types have been specified
    (e.g., Frame Realy, Ethernet, ATM). Investigation into
    and specification of a "generic PW" type and/or MPLS PW
    should be undertaken.

    PWE3 will specify a PW type for the special case where the
    access service payloads at both ends are known to consist
    entirely of IP packets. PWE3 will not specify mechanisms
    by which a PW connects two different access services
    unless the Network Layer protocol is IP or MPLS.

    Specify the control and management functions of chartered PW
    types, to include PW setup, configuration, maintenance and
    tear-down. The PWE3 WG will do this in its entirety for
    MPLS PSNs, and the L2TPEXT WG will develop the L2TP specifics
    for L2TPv3-based PWs.

    Specify Operations and Management (OAM) mechanisms for all
    PW types, suitable for operation over both IP/L2TPv3 and
    MPLS PSNs, and capable of providing the necessary
    interworking with the OAM mechanisms of the emulated
    service.

    Define requirements for and mechanisms to provide
    interconnection of PWs (to include inter-domain PWs).

    Define requirements for and mechanisms to provide
    protection and restoration of PWs.

    Publish document outlining PW-specific congestion avoidance
    and response guidelines.

    Publish document outlining PW-specific security
    considerations.

    Specify requirements and mechanisms for P2MP functionality
    for PWs. This work will be coordinated with the L2VPN and
    MPLS working groups.

    Publish requirements and specification for PW to take
    advantage of multiple PSN paths that exist between PEs.

    Publish requirements and specification for enhanced OAM.

    Include extensions to the PWE3 protocols and RFCs
    necessary to create an MPLS Transport Profile (MPLS-TP).
    The work on the MPLS TP needs to be coordinated between
    three primary working groups (MPLS, PWE3, L2VPN and CCAMP) that
    are chartered to do MPLS TP work.

    Goals and Milestones:

    Done  PWE3 WG started, organize editing teams.
    Done  Hold interim meeting, including discussion of priority of service-specific documents and consider pruning some deliverables
    Done  Accept drafts of service-specific documents as WG items
    Done  PW Requirements Document Last Call
    Done  TDM Circuit Documents Last Call
    Done  ATM Documents Last Call
    Done  Ethernet Documents Last Call
    Done  Fragmentation LC
    Done  TDM Requirements LC
    Done  SONET Documents Last Call
    Done  TDM Documents Last Call
    Done  Frame Relay Documents Last Call
    Done  FCS retention Last Call
    Done  Multi-Segment PW Requirements LC
    Done  VCCV LC
    Done  PWE3 Services MIBs LC
    Done  PPP/HDLC PW LC
    Done  Wildcard FEC LC
    Done  TDM Signaling LC
    Jul 2008  Multi-Segment Architecture LC
    Done  Basic Pseudowire MIBs LC
    Sep 2008  Fiber Channel Encap LC
    Sep 2008  PW OAM Mapping LC
    Sep 2008  Congestion Framework LC
    Oct 2008  Multi-Segment PW LC
    Dec 2008  PW Protection and Restoration Requirements LC
    Dec 2008  PW Congestion Response LC
    Dec 2008  Generic PW Requirements
    Jan 2009  Dynamic MS PW LC
    Mar 2009  PW Protection and Restoration Architecture
    Mar 2009  Multipath PW LC
    Mar 2009  Generic Associated Channel Header LC
    Apr 2009  MPLS PW LC
    Jul 2009  PW Protection and Restoration LC
    Jul 2009  Multisegment PW MIB
    Jul 2009  Congestion Solution LC
    Jul 2009  Security Considerations LC
    Jul 2009  P2MP Requirements LC
    Dec 2009  Enhanced PW OAM
    Dec 2009  VCCV Extensions for MPLS-TP
    Dec 2009  Tandem Connection Monitoring for PWs

    Internet-Drafts:

    Pseudowire (PW) Management Information Base (MIB) (128939 bytes)
    Pseudowire (PW) over MPLS PSN Management Information Base (MIB) (62692 bytes)
    Definitions of Textual Conventions for Pseudowires (PW) Management (19090 bytes)
    SONET/SDH Circuit Emulation Service Over Packet (CEP) Management Information Base (MIB) Using SMIv2 (131124 bytes)
    Ethernet Pseudowire (PW) Management Information Base (MIB) (43512 bytes)
    Managed Objects for ATM over Packet Switched Network (PSN) (73158 bytes)
    Managed Objects for TDM over Packet Switched Network (PSN) (81329 bytes)
    Pseudo Wire (PW) OAM Message Mapping (76458 bytes)
    Segmented Pseudowire (94689 bytes)
    An Architecture for Multi-Segment Pseudowire Emulation Edge-to-Edge (55997 bytes)
    Encapsulation Methods for Transport of Fibre Channel frames Over MPLS Networks (37706 bytes)
    Bidirectional Forwarding Detection (BFD) for the Pseudowire Virtual Circuit Connectivity Verification (VCCV) (29248 bytes)
    Preferential Forwarding Status bit definition (67147 bytes)
    Pseudowire (PW) Redundancy (33450 bytes)
    Requirements for Point-to-Multipoint Pseudowire (45056 bytes)
    LDP extensions for AII reachability (23781 bytes)
    Reliable Fibre Channel Transport Over MPLS Networks (71413 bytes)

    Request For Comments:

    Requirements for Pseudo-Wire Emulation Edge-to-Edge (PWE3) (RFC 3916) (43856 bytes)
    PWE3 Architecture (RFC 3985) (95062 bytes)
    Requirements for Edge-to-Edge Emulation of Time Division Multiplexed (TDM) Circuits over Packet Switching Networks (RFC 4197) (47937 bytes)
    Pseudowire Emulation Edge-to-Edge (PWE3) Control Word for Use over an MPLS PSN (RFC 4385) (22440 bytes)
    Encapsulation Methods for Transport of Ethernet Over MPLS Networks (RFC 4448) (49012 bytes)
    Pseudowire Setup and Maintenance using the Label Distribution Protocol (LDP) (RFC 4447) (76204 bytes)
    IANA Allocations for Pseudowire Edge to Edge Emulation (PWE3) (RFC 4446) (19782 bytes)
    Structure-Agnostic Time Division Multiplexing (TDM) over Packet (SAToP) (RFC 4553) (58141 bytes)
    Pseudowire Emulation Edge-to-Edge (PWE3) Fragmentation and Reassembly (RFC 4623) (36369 bytes)
    Encapsulation Methods for Transport of Frame Relay Over MPLS Networks (RFC 4619) (38193 bytes)
    Encapsulation Methods for Transport of PPP/High-Level Data Link Control (HDLC) over MPLS Networks (RFC 4618) (33141 bytes)
    Pseudowire Emulation Edge-to-Edge (PWE3) Frame Check Sequence Retention (RFC 4720) (18248 bytes)
    Encapsulation Methods for Transport of Asynchronous Transfer Mode (ATM) over MPLS Networks (RFC 4717) (86173 bytes)
    Pseudowire Emulation Edge-to-Edge (PWE3) Asynchronous Transfer Mode (ATM) Transparent Cell Transport Service (RFC 4816) (10269 bytes)
    Synchronous Optical Network/Synchronous Digital Hierarchy SONET/SDH) Circuit Emulation over Packet (CEP)) (RFC 4842) (96719 bytes) obsoletes RFC 5143
    Wildcard Pseudowire Type (RFC 4863) (11321 bytes)
    Attachment Individual Identifier (AII) Types for Aggregation (RFC 5003) (14559 bytes)
    Structure-Aware Time Division Multiplexed (TDM) Circuit Emulation Service over Packet Switched Network (CESoPSN) (RFC 5086) (83233 bytes)
    Time Division Multiplexing over IP (TDMoIP) (RFC 5087) (113071 bytes)
    Pseudowire Virtual Circuit Connectivity Verification (VCCV) A Control Channel for Pseudowires (RFC 5085) (67853 bytes)
    Control Protocol Extensions for the Setup of Time-Division Multiplexing (TDM) Pseudowires in MPLS Networks (RFC 5287) (33070 bytes)
    Requirements for Multi-Segment Pseudowire Emulation Edge-to-Edge (PWE3) (RFC 5254) (64584 bytes)
    IETF Secretariat - Please send questions, comments, and/or suggestions to ietf-web@ietf.org.

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