Path Computation Element Communication Protocol (PCEP) Requirements and Protocol Extensions in Support of Global Concurrent Optimization

The Path Computation Element (PCE) is a network component, application, or node that is capable of performing path computations at the request of Path Computation Clients (PCCs). The PCE is applied in Multiprotocol Label Switching Traffic Engineering (MPLS-TE) networks and in Generalized MPLS (GMPLS) networks to determine the routes of Label Switched Paths (LSPs) through the network. The Path Computation Element Communication Protocol (PCEP) is specified for communications between PCCs and PCEs, and between cooperating PCEs. When computing or re-optimizing the routes of a set of LSPs through a network it may be advantageous to perform bulk path computations in order to avoid blocking problems and to achieve more optimal network- wide solutions. Such bulk optimization is termed Global Concurrent Optimization (GCO). A Global Concurrent Optimization is able to simultaneously consider the entire topology of the network and the complete set of existing LSPs, and their respective constraints, and look to optimize or re-optimize the entire network to satisfy all constraints for all LSPs. The Global Concurrent Optimization (GCO) application is primarily an NMS based solution. This document provides application-specific requirements and the PCEP extensions in support of a global concurrent optimization (GCO) application.