Patent ID: 7346277

Claim:
A method for restoring service after a failure in a multi-layer network capable of operating at two or more different network layers, the network comprising a plurality of nodes, at least one node capable of operating at more than one network layer, the method comprising the steps of: detecting the failure; and modifying the operations of one or more of the nodes at two or more different network layers to restore at least some portion of the service affected by the failure by routing around the failure, wherein: the multi-layer network is a packet-over-optical network having a packet layer and an optical layer; one or more nodes operate at both the packet and optical layers; each node operating at both the packet and optical layers comprises an optical cross-connect (OXC) and a packet router; the step of modifying the node operations comprises the steps of: modifying optical-layer processing of at least one of the OXCs; and modifying packet-layer processing of at least one of the packet routers; prior to the failure, first and second packet streams are transmitted within a single optical channel to a transit packet router that demultiplexes the single optical channel for further transmission of each packet stream within a different optical channel; and when the failure is a failure of the transit packet router, the step of modifying the node operations comprises the steps of: modifying the packet-layer processing of an other packet router to cause that other packet router to generate two different optical channels for the first and second packet streams; and modifying the optical-layer processing of one or more OXCs to route the two different optical channels.