Path Computation Element
|Document||Charter||Path Computation Element WG (pce) Snapshot|
|Title||Path Computation Element|
|IESG||Responsible AD||John Scudder|
|Charter edit AD||John Scudder|
|Send notices to||(None)|
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 not be physically located on each head-end LSR. The TEAS Working Group is responsible for defining and extending architectures for Traffic Engineering (TE) and it is expected that the PCE and TEAS WGs will work closely together on elements of TE architectures that utilize PCE. The PCE WG works on the 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 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 protocols specified in the CCAMP and TEAS WGs. Work Items: - PCEP extensions to support MPLS and GMPLS Traffic Engineered LSP path computation models involving PCEs. 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 the TEAS Working Group, development of PCE- based architectures for Traffic Engineering. - 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 expressing path computation requests and responses in the various GMPLS-controlled networks, including WSON. - Definition of PCEP extensions for path computation in multi-layer networks. - Definition of the PCEP extensions used by a stateful PCE for recommending a new path for an existing or new LSP to the PCC/PCE. Further protocol extensions must cover the case where receiving PCC/PCE chooses to not follow the recommendation.