Status update for WG pce

The PCE working group is responsible for the Path Communication Element Communication Protocol (PCEP).  PCEP allows a Path Computation Client (PCC - for example, a head-end router) to request paths from, or have paths created by, a Path Computation Server (PCE).

The WG is concluding the recent effort on generalizing PCEP to include segment routing paths for an MPLS data plane [1].  Another piece of work reaching its conclusion is the extension of PCEP for GMPLS networks [2].  

The WG is progressing the work related to use of PCE (and PCEP) for the hierarchy of controllers (as per the Abstraction and Control of TE networks (ACTN) framework). We are also concluding the protocol extensions to allow for a hierarchical structure of PCEs (H-PCE) which provides a parent PCE to coordinate the operation of per-domain child PCEs [3]. We have made progress in moving the Stateful operations for P2MP TE tunnels [7] (used by Multicast applications) and automatic bandwidth adjustments [8].  

The WG is actively working on adding to PCEP the concept of an "association group" which binds together arbitrary sets of LSPs and/or policies for the purposes of path computation.  The base draft for this [4] is very flexible and allows for many follow-on innovations, ranging from associations reflecting common policies to those mandating resource diversity and other relationships such as bidirectionality and resource sharing. Another significant piece of work in progress is the extension that allows a PCE to act as a central controller, by instantiating path state on each hop in an LSP [5] and using a flow specifier to add traffic classification to the head-end node of the LSP [6]. 

[Last Updated: March 26, 2019.]