Internet Engineering Task Force

Path Computation Element (pce)

Last Modified: 2011-08-18

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

Chair(s):

Routing Area Director(s):

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:

PCC-PCE Communication and PCE Discovery Requirements for Inter-Layer Traffic Engineering (29084 bytes)
Extensions to the Path Computation Element communication Protocol (PCEP) for Inter-Layer MPLS and GMPLS Traffic Engineering (39809 bytes)
Requirements for GMPLS applications of PCE (30593 bytes)
Conveying Vendor-Specific Constraints in the Path Computation Element Protocol (27866 bytes)
PCEP Requirements for WSON Routing and Wavelength Assignment (26197 bytes)
PCEP extensions for GMPLS (70460 bytes)
PCE-based Computation Procedure To Compute Shortest Constrained P2MP Inter-domain Traffic Engineering Label Switched Paths (56557 bytes)
The Application of the Path Computation Element Architecture to the Determination of a Sequence of Domains in MPLS and GMPLS (69831 bytes)

Request For Comments: