Patent ID: 7860392

Claim:
An apparatus comprising: a wavelength division multiplexing optical network including a plurality of nodes, said plurality of nodes including a plurality of access nodes each to generate and transmit to adjacent nodes connectivity request messages to determine a network topology for each of the plurality of access nodes, the network topology for each of the access nodes comprising possible end to end paths from that access node as a source node to all other access nodes as destinations, wherein an end to end path is a series of three or more of the plurality of nodes connected by links on which a set of wavelengths is available for establishing a lightpath, and wherein allocated and unallocated wavelengths are considered available wavelengths, wherein the set of wavelengths on a possible end to end path includes at least those wavelengths common on all of the links of that possible end to end path; and each of said plurality of nodes, responsive to each received connectivity request message originated by others of the plurality of access nodes, to determine any adjacent nodes to which an identified possible end to end path that the received connectivity request message has already collected can be extended to form additional possible end to end paths having the originating access node as the source node, to transmit a message carrying that determination for incorporation into a topology database back to the originating access node of the received connectivity request message, and to propagate an updated version of said received connectivity request message to selected adjacent nodes that may be able to determine further additional possible end to end paths having the originating access node as the source node, wherein the node that transmits the message carrying that determination is coupled to the destination node of a path included in that transmitted message.