Patent ID: 7474850
Filing Date: 2009-01-06
Classification: H04B,H04J,H04Q

Abstract:
1. A method performed by a node of a wavelength multiplex optical network, the method comprising: detecting at an access node that at least a portion of a first path of an optical circuit fails based on a loss of a light of the at least a portion of the first path; in response to the detection, determining whether the access node is a source node of the optical circuit in response to the detection; and if the access node is the source node of the optical circuit, the access node provisioning a second path leading to a destination node of the first path without waiting for an update of a routing database regarding the failure of the first path, the routing database storing available paths from a source node to reachable destination nodes in the optical network, wherein the routing database is subsequently updated to indicating a failure of the first path; if the access node is not a source node, determining whether the access node is a destination node of the optical circuit; and notifying the source node of the optical circuit by turning off a light of a returning path leading to the source node of the optical circuit, if the access node is the destination node of the optical circuit, wherein the second path satisfies a predetermined set of disjointness requirements with respect to the first path, the predetermined set of disjointness requirements including at least one of a node disjoint, a link disjoint, a maximally node disjoint, and a maximally link disjoint requirements.