Conveying policies associated with traffic engineering paths over PCEP session

This document describes a simple extension to the Path Computation Element (PCE) Communication Protocol (PCEP) using which a PCEP speaker can enforce one or more policies on the other PCEP speaker. A policy is represented by a numeric value which can be interpreted only by the receiving PCEP speaker. Using the proposed extension, a path computation client (PCC) can signal one or more policies that must be taken into consideration by a PCE during path computation. Similarly, when initiating or updating a path, a stateful PCE can signal one or more policies (e.g., traffic steering rules) that a PCC is expected to apply to the path.