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

 Charter
 Last Modified: 2011-12-09

 Current Status: Active Working Group

 Chair(s):
     JP Vasseur  <jpv@cisco.com>
     Julien Meuric  <julien.meuric@orange.com>

 Routing Area Director(s):
     Stewart Bryant  <stbryant@cisco.com>
     Adrian Farrel  <adrian@olddog.co.uk>

 Routing Area Advisor:
     Adrian Farrel  <adrian@olddog.co.uk>

 Secretary(ies):
     Daniel King  <daniel@olddog.co.uk>

 Mailing Lists: 
     General Discussion:pce@ietf.org
     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 the required protocols so
as to enable 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 Engineered LSPs.

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

The PCE WG works on application of this model within a single domain
or within a 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 specifies the PCE communication Protocol (PCEP) and needed
extensions for communication between LSRs (termed Path Computation
Clients - PCCs) and PCEs, and between cooperating PCEs. Security
mechanisms such as authentication and confidentiality are included.

The WG determines requirements for extensions to existing routing and
signaling protocols in support of the PCE architecture and the signaling
of inter-domain paths (e.g. RSVP-TE and its GMPLS variations). Any
necessary extensions will be produced in collaboration with the Working
Groups responsible for the protocols.

The WG also works on the mechanisms to for multi-layer path computation
and PCEP extensions for communication between several network layers.

The WG defines the required PCEP extensions for Wavelength Switched
Optical Networks (WSON) while keeping consistency with the GMPLS
architecture specified in the CCAMP WG.

Work Items:

- PCEP extensions for MPLS and GMPLS Traffic Engineered LSP path
  computation models involving PCE(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. Both intra- and inter-domain
  applications are covered.
- In cooperation with protocol specific Working Group (e.g., MPLS,
  CCAMP), development of LSP signaling (RSVP-TE) extensions required
  to support PCE-based path computation models.
- Specification of PCEP extensions for communication in the various
  GMPLS-controlled networks, including WSON.
- Definition of PCEP extensions for path computation in multi-layer
  networks.
 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 

   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 

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

   Done         Submit applicability and metrics documents to the IESG 

   Oct 2011       Submit WSON requirements to the IESG to be considered as an 
                Informational RFC 

   Dec 2011       Submit extensions for hierarchical PCE path computation model 
                as WG document 

   Jan 2012       Submit the PCEP MIB to the IESG to be considered as a Proposed 
                Standard 

   Jan 2012       Submit P2MP MIB as a WG document 

   Feb 2012       Submit the discovery MIB to the IESG to be considered as a 
                Proposed Standard 

   Feb 2012       Submit inter-layer extensions to the IESG to be considered as a 
                Proposed Standard 

   Mar 2012       Submit inter-area/AS applicability statement to the IESG as an 
                informational RFC 

   Mar 2012       Submit PCEP extensions for WSON as a WG document 

   Apr 2012       Submit the GMPLS requirements to the IESG to be considered as 
                an Informational RFC 

   Jun 2012       Submit PCEP extensions for GMPLS to the IESG to be considered 
                as a Proposed Standard 

   Aug 2012       Submit PCEP extensions for WSON to the IESG to be considered as 
                a Proposed Standard 

   Oct 2012       Submit P2MP MIB to the IESG to be considered as a Proposed 
                Standard 

   Feb 2013       Submit extensions for hierarchical model to the IESG to be 
                considered as a Proposed Standard 

   Mar 2013       Evaluate WG progress, recharter or close 


 Internet-Drafts:

Posted Revised         I-D Title   <Filename>
------ ------- --------------------------------------------
Feb 2008 Jan 2012   <draft-ietf-pce-inter-layer-ext-06.txt>
                Extensions to the Path Computation Element communication 
                Protocol (PCEP) for Inter-Layer MPLS and GMPLS Traffic 
                Engineering 

Jul 2009 Dec 2011   <draft-ietf-pce-vendor-constraints-05.txt>
                Conveying Vendor-Specific Constraints in the Path Computation 
                Element Protocol 

Sep 2009 Oct 2011   <draft-ietf-pce-wson-routing-wavelength-06.txt>
                PCEP Requirements for WSON Routing and Wavelength Assignment 

Sep 2010 Oct 2011   <draft-ietf-pce-gmpls-pcep-extensions-04.txt>
                PCEP extensions for GMPLS 

Sep 2011 Oct 2011   <draft-ietf-pce-pcep-inter-domain-p2mp-procedures-01.txt>
                PCE-based Computation Procedure To Compute Shortest Constrained 
                P2MP Inter-domain Traffic Engineering Label Switched Paths 

Oct 2011 Oct 2011   <draft-ietf-pce-hierarchy-fwk-00.txt>
                The Application of the Path Computation Element Architecture to 
                the Determination of a Sequence of Domains in MPLS and 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 

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

RFC5088 PS   Jan 2008    OSPF 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 

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

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

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 

RFC6123 H    Feb 2011    Inclusion of Manageability Sections in Path Computation 
                       Element (PCE) Working Group Drafts 

RFC6457 I    Dec 2011    PCC-PCE Communication and PCE Discovery Requirements for 
                       Inter-Layer Traffic Engineering