Patent ID: 7831700

Claim:
A distributed Path Computation Element based (PCE-based) system in a multi-layer network, comprising: at least one higher-layer Path Computation Element (PCE); at least one lower-layer PCE; at least one higher-layer Traffic Engineering Database (TED) that provides relevant Traffic Engineering link information to the at least one higher-layer PCE; at least one lower-layer TED that provides relevant Traffic Engineering link information to the at least one lower-layer PCE; and at least one Path Computation Element Agent (PCE Agent) that manages off-line path computations without a request from the higher-layer PCE; wherein the at least one higher-layer PCE and the at least one lower-layer PCE function cooperatively for multi-layer path computations, wherein the PCE Agent is in communication with the lower-layer PCE and not in direct communication with the higher-layer PCE, and wherein the at least one lower-layer PCE is a physical layer PCE and the at least one higher-layer PCE is a non-physical layer PCE.