Path Computation Element (pce)

Path Computation Element (pce)
------------------------------

Charter
Last Modified: 2010-07-09

Current Status: Active Working Group

Chair(s):
JP Vasseur <[email protected]>
Julien Meuric <[email protected]>

Routing Area Director(s):
Stewart Bryant <[email protected]>
Adrian Farrel <[email protected]>

Routing Area Advisor:
Adrian Farrel <[email protected]>

Secretary(ies):
Daniel King <[email protected]>

Mailing Lists:
General Discussion:[email protected]
To Subscribe: http://www.ietf.org/mailman/listinfo/pce
Archive: http://www.ietf.org/mail-archive/web/pce/

Description of Working Group:

The PCE Working Group is chartered to specify a Path Computation Element
(PCE) based architecture for the computation of paths for MPLS and GMPLS
Point to Point and Point to Multi-point Traffic Engineering LSPs.

In this architecture path computation does not occur on the head-end
(ingress) LSR, but on some other path computation entity that may
physically not be located on the head-end LSR.

The PCE WG will work on application of this model within a single Domain
or within a small group of domains (where a domain is a layer, IGP area
or Autonomous System with limited visibility from the head-end LSR). At
this time, applying this model to large groups of domains such as the
Internet is not thought to be possible, and the PCE WG will not spend
energy on that topic.

The WG will specify a protocol for communication between LSRs (termed
Path Computation Clients - PCCs) and PCEs, and between cooperating PCEs.
This protocol will be capable of representing requests for path
computation including a full set of constraints, will be able to return
multiple paths, and will include security mechanisms such as
authentication and confidentiality.

The WG will determine requirements for extensions to existing routing
and signaling protocols in support of PCE discovery and signaling of
inter-domain paths. Candidate protocols for extensions are RSVP-TE,
OSPF-TE, ISIS-TE and BGP. Any necessary extensions will be produced in
collaboration with the Working Groups responsible for the protocols.

The Working Group will also work on the definition of metrics to
evaluate path quality, scalability, responsiveness and robustness of
path computation models.

Work Items:

- Functional specification of MPLS and GMPLS Traffic Engineered LSP path
computation models involving Path Computation Element(s). This includes
the case of computing the paths of intra and inter-domain TE LSPs. Such
path computation includes the generation of primary, protection and
recovery paths, as well as computations for (local/global)
reoptimization and load balancing. The WG will address the inter-area
(single IGP domain) scenario first. WG progress will be evaluated before
inter-AS related work is started.
- Specification of the PCE-based architecture.
- Specification of requirements and protocol extensions related to the
policy, and security aspects of PCE-based path computation involving
PCEs of multiple administrative entities.
- In cooperation with protocol specific Working Group (OSPF, ISIS, IDR,
MPLS, CCAMP), development of routing (OSPF, ISIS, BGP) and LSP signaling
(RSVP-TE) extensions required to support PCE-based path computation
models.
- Specification of techniques in support of PCE discovery within and
across domains. Where such techniques result in the extensions of
existing protocols (e.g., OSPF, ISIS or BGP), this work will be done in
conjunction with the appropriate WGs.
- Specification of a new communication protocol for use between a PCC
and a PCE, and between PCEs. A single protocol will be selected from
among candidates that include the existing protocols defined in other
WGs.
- Definition of objective metrics to evaluate various criteria such as
the measurement of path quality, response time, robustness and
scalability of path computation models.

Review of the document "Requirements for path computation element in
GMPLS inter-domain networks" produced by the CCAMP WG.

Goals and Milestones:

Done Submit first draft of PCE architecture document

Done Submit first draft of PCE discovery requirements and protocol
extensions documents

Done Submit first draft of the PCE communication protocol
requirements

Done Submit first draft of the definition of objective metrics

Done Submit first draft of the PCE communication protocol
specification

Done Submit PCE architecture specification to the IESG to be
considered as Informational RFC

Done Submit first draft of the MIB module for the PCE protocol

Done Submit PCE communication protocol requirements to the IESG to
be considered as an Informational RFC

Done Submit PCE discovery protocol extensions specifications to the
IESG to be considered as a Proposed Standard

Done Submit PCE communication protocol specification to the IESG to
be considered as a Proposed Standard

Jun 2008 Submit first draft of applicability statement (describing the
processes and procedures for the use of the PCE architecture,
protocols and protocol extensions for inter-area MPLS and GMPLS
Traffic Engineering)

Done Submit first draft of the PCE P2MP communication requirements

Done Submit first draft of the PCE P2MP PCEP protocol extensions

Done Submit PCE P2MP communication requirements to the IESG to be
considered as an Informational RFC

Nov 2008 Submit applicability statement to the IESG as informational RFC

Done Submit PCE P2MP PCEP protocol extensions to the IESG to be
considered as an Proposed Standard RFC

Feb 2009 Submit the PCE MIB Internet-Draft to the IESG for consideration
as Proposed Standard

Done Submit applicability and metrics documents to the IESG

Feb 2009 Evaluate WG progress, recharter or close

Internet-Drafts:

Posted Revised I-D Title <Filename>
------ ------- --------------------------------------------
Nov 2005 Sep 2010 <draft-ietf-pce-inter-layer-req-12.txt>
PCC-PCE Communication and PCE Discovery Requirements for
Inter-Layer Traffic Engineering

Jan 2007 Sep 2010 <draft-ietf-pce-manageability-requirements-11.txt>
Inclusion of Manageability Sections in PCE Working Group Drafts

Feb 2008 Jul 2010 <draft-ietf-pce-inter-layer-ext-04.txt>
Extensions to the Path Computation Element communication
Protocol (PCEP) for Inter-Layer MPLS and GMPLS Traffic
Engineering

Sep 2008 Jul 2010 <draft-ietf-pce-gmpls-aps-req-02.txt>
Document: draft-ietf-pce-gmpls-aps-req-02.txt

Jan 2009 Jul 2010 <draft-ietf-pce-pcep-mib-02.txt>
PCE communication protocol(PCEP) Management Information Base

Mar 2009 Sep 2010 <draft-ietf-pce-vpn-req-02.txt>
PCC-PCE Communication Requirements for VPNs

Jul 2009 Sep 2010 <draft-ietf-pce-vendor-constraints-02.txt>
Conveying Vendor-Specific Constraints in the Path Computation
Element Protocol

Sep 2009 Aug 2010 <draft-ietf-pce-wson-routing-wavelength-02.txt>
PCEP Requirements for WSON Routing and Wavelength Assignment

Sep 2010 Sep 2010 <draft-ietf-pce-gmpls-pcep-extensions-00.txt>
PCEP extensions for GMPLS

Request For Comments:

RFC Stat Published Title
------- -- ----------- ------------------------------------
RFC4655 I Aug 2006 A Path Computation Element (PCE) Based Architecture

RFC4657 I Sep 2006 Path Computation Element (PCE) Communication Protocol
Generic Requirements

RFC4674 I Oct 2006 Requirements for Path Computation Element (PCE)
Discovery

RFC4927 I Jun 2007 PCE Communication Protocol (PCECP) Specific Requirements
for Inter-Area Multi Protocol Label Switching (MPLS) and
Generalized MPLS (GMPLS) Traffic Engineering

RFC5088 PS Jan 2008 OSPF Protocol Extensions for Path Computation Element
(PCE) Discovery

RFC5089 PS Jan 2008 IS-IS Protocol Extensions for Path Computation Element
(PCE) Discovery

RFC5376 I Nov 2008 Inter-AS Requirements for the Path Computation Element
Communication Protocol (PCECP)

RFC5394 I Dec 2008 Policy-Enabled Path Computation Framework

RFC5440 PS Mar 2009 Path Computation Element (PCE) Communication Protocol
(PCEP)

RFC5455 PS Mar 2009 Diff-Serv Aware Class Type Object for Path Computation
Element Communication Protocol

RFC5441 PS Apr 2009 A Backward Recursive PCE-Based Computation (BRPC)
Procedure To Compute Shortest Constrained Inter-Domain
Traffic Engineering Label Switched Paths

RFC5521 PS Apr 2009 Extensions to the Path Computation Element Communication
Protocol (PCEP) for Route Exclusions

RFC5520 PS Apr 2009 Preserving Topology Confidentiality in Inter-Domain Path
Computation Using a Path-Key-Based Mechanism

RFC5541 PS Jun 2009 Encoding of Objective Functions in the Path Computation
Element Communication Protocol (PCEP)

RFC5557 PS Jul 2009 Path Computation Element Communication Protocol (PCEP)
Requirements and Protocol Extensions in Support of
Global Concurrent Optimization

RFC5623 I Sep 2009 Framework for PCE-Based Inter-Layer MPLS and GMPLS
Traffic Engineering

RFC5671 I Oct 2009 Applicability of the Path Computation Element (PCE) to
Point-to-Multipoint (P2MP) Multiprotocol Label Switching
(MPLS) and Generalized MPLS (GMPLS) Traffic Engineering
(TE)

RFC5862 I Jun 2010 Path Computation Clients (PCC) - Path Computation
Element (PCE) Requirements for Point-to-Multipoint
MPLS-TE

RFC5886 PS Jun 2010 A Set of Monitoring Tools for Path Computation Element
(PCE)-Based Architecture

RFC6006 PS Sep 2010 Extensions to the Path Computation Element Communication
Protocol (PCEP) for Point-to-Multipoint Traffic
Engineering Label Switched Paths

RFC6007 I Sep 2010 Use of the Synchronization VECtor (SVEC) List for
Synchronized Dependent Path Computations