Path Computation Element Communication Protocol (PCECP) Specific Requirements for Inter-Area MPLS and GMPLS Traffic Engineering

Status of This Memo This memo provides information for the Internet community. It does not specify an Internet standard of any kind. Distribution of this memo is unlimited. Abstract For scalability purposes, a network may comprise multiple Interior Gateway Protocol (IGP) areas. An inter-area Traffic Engineered Label Switched Path (TE-LSP) is an LSP that transits through at least two IGP areas. In a multi-area network, topology visibility remains local to a given area, and a head-end Label Switching Router (LSR) cannot compute an inter-area shortest constrained path. One key application of the Path Computation Element (PCE)-based architecture is the computation of inter-area TE-LSP paths. The PCE Communication Protocol (PCECP) is used to communicate computation requests from Path Computation Clients (PCCs) to PCEs, and to return computed paths in responses. This document lists a detailed set of PCECP-specific requirements for support of inter-area TE-LSP path computation. It complements the generic requirements for a PCE Communication Protocol.