Pseudowire Emulation Edge to Edge (pwe3) Charter

2.3.20 Pseudowire Emulation Edge to Edge (pwe3)

NOTE: This charter is a snapshot of the 68th IETF Meeting in Prague, Czech Republic. It may now be out-of-date.

Last Modified: 2007-03-06

Chair(s):

Stewart Bryant <stbryant@cisco.com>
Danny McPherson <danny@arbor.net>

Internet Area Director(s):

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

Internet Area Advisor:

Mark Townsley <townsley@cisco.com>

Secretary(ies):

Matthew Bocci <matthew.bocci@alcatel-lucent.co.uk>

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.

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 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 two endpoints of the PW.

PWE3 will investigate mechanisms necessary to perform clock
recovery and other real-time signaling functions. This work will
be coordinated with the AVT WG and RTP will be used where
appropriate.

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.

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.

PWE3 will work closely with the L2VPN WG to ensure a clear
demarcation is defined for where PWE3 stops and L2VPN starts.
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.

WG Objectives:

Specify the following PW types:

Ethernet, Frame Relay, PPP, HDLC, ATM, low-rate TDM,
SONET/SDH and Fibre Channel.

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.

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.

Further enhance PW specifications to enable more transparent
emulation when necessary, for example the retention of FCS
across a PW.

Define a mechanism for MPLS PWs that provides interoperability
with currently deployed equal cost multiple path (ECMP)
algorithms such that packets for a given PW follow the same
path through an MPLS PSN.

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.

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
Apr 2007		PW OAM Mapping LC
May 2007		Fiber Channel LC
May 2007		Multi-Segment PW Architecture LC
Jun 2007		TDM Signaling LC
Sep 2007		PW Protection and Restoration Architecture
Sep 2007		PW Protection and Restoration Requirements LC
Nov 2007		Multi-Segment PW LC
May 2008		PW Protection and Restoration LC

Internet-Drafts:

draft-ietf-pwe3-pw-mib-10.txt

draft-ietf-pwe3-pw-mpls-mib-11.txt

draft-ietf-pwe3-pw-tc-mib-10.txt

draft-ietf-pwe3-sonet-14.txt

draft-ietf-pwe3-cep-mib-09.txt

draft-ietf-pwe3-enet-mib-10.txt

draft-ietf-pwe3-vccv-13.txt

draft-ietf-pwe3-pw-atm-mib-02.txt

draft-ietf-pwe3-cesopsn-07.txt

draft-ietf-pwe3-tdmoip-06.txt

draft-ietf-pwe3-tdm-mib-07.txt

draft-ietf-pwe3-oam-msg-map-05.txt

draft-ietf-pwe3-ms-pw-requirements-04.txt

draft-ietf-pwe3-segmented-pw-04.txt

draft-ietf-pwe3-tdm-control-protocol-extensi-02.txt

draft-ietf-pwe3-dynamic-ms-pw-02.txt

draft-ietf-pwe3-ms-pw-arch-02.txt

draft-ietf-pwe3-wildcard-pw-type-02.txt

draft-ietf-pwe3-aii-aggregate-02.txt

draft-ietf-pwe3-fc-encap-02.txt

draft-ietf-pwe3-congestion-frmwk-00.txt

Request For Comments:

RFC	Status	Title
RFC3916	I	Requirements for Pseudo-Wire Emulation Edge-to-Edge (PWE3)
RFC3985	I	PWE3 Architecture
RFC4197	I	Requirements for Edge-to-Edge Emulation of Time Division Multiplexed (TDM) Circuits over Packet Switching Networks
RFC4385	PS	Pseudowire Emulation Edge-to-Edge (PWE3) Control Word for Use over an MPLS PSN
RFC4446	BCP	IANA Allocations for Pseudowire Edge to Edge Emulation (PWE3)
RFC4447	PS	Pseudowire Setup and Maintenance using the Label Distribution Protocol (LDP)
RFC4448	PS	Encapsulation Methods for Transport of Ethernet Over MPLS Networks
RFC4553	PS	Structure-Agnostic Time Division Multiplexing (TDM) over Packet (SAToP)
RFC4618	PS	Encapsulation Methods for Transport of PPP/High-Level Data Link Control (HDLC) over MPLS Networks
RFC4619	PS	Encapsulation Methods for Transport of Frame Relay Over MPLS Networks
RFC4623	PS	Pseudowire Emulation Edge-to-Edge (PWE3) Fragmentation and Reassembly
RFC4717	PS	Encapsulation Methods for Transport of Asynchronous Transfer Mode (ATM) over MPLS Networks
RFC4720	PS	Pseudowire Emulation Edge-to-Edge (PWE3) Frame Check Sequence Retention
RFC4816	PS	Pseudowire Emulation Edge-to-Edge (PWE3) Asynchronous Transfer Mode (ATM) Transparent Cell Transport Service

Meeting Minutes

Slides

PW Security - Yaakov Stein
Segmented PW update - Luca Martini
PW Redundancy - Praveen Muley
Pseudowire Preferential Forwarding Status bit definition - Mustapha Aissaoui
OSPF extensions for MS-PW - Andrew Dolganow
P2MP PW Requirements - Frederic Jounay
Precision Time Protocol (IEEE1588) - Ron Cohen
Draft Status