Patent ID: 8290366

Claim:
A method, comprising: sending a discovery advertisement to a plurality of path computation elements (PCEs), wherein the discovery advertisement requests a routing and wavelength assignment (RWA)-capability information from each of the PCEs; receiving a discovery response comprising the RWA-capability information from at least one of the PCEs, wherein the RWA-capability information indicates whether the corresponding PCE is RWA-capable; determining which PCEs are RWA-capable PCEs based on the PCE capability information; sending a request comprising a lightpath constraint and a RWA computation option to a selected RWA-capable PCE; and receiving a reply from the selected RWA-capable PCE, wherein the request and the reply are communicated using a PCE protocol, and wherein when a valid path is found, the reply comprises a route, wavelengths assigned to the route, and an indication of which computation option has been applied, or wherein in the case where a valid path is not found, the PCRep message includes a reason why the path is not found.