Path Computation Element Protocol (PCEP)

A Path Computation Element (PCE) is an entity (component, application, or network node) that is capable of computing a network path or route based on a network graph and applying computational constraints. A Path Computation Client (PCC) is any client application requesting a path computation to be performed by a PCE. The Path Computation Element Protocol (PCEP) enables communications between a PCC and a PCE, or between two PCEs (defined in RFC 5440). PCEP is a TCP-based protocol defined by the IETF PCE Working Group, and defines a set of messages and objects used to manage PCEP sessions and to request and send paths for multidomain traffic engineered LSPs (TE LSPs). It provides a mechanism for a PCE to perform path computation for a PCC's external LSPs. The PCEP interactions include LSP status reports sent by the PCC to the PCE, and PCE updates for the external LSPs.