Connection rerouting/network reconfiguration

Optical networks employing wavelength division multiplexing can carry huge volumes of traffic, hence maintaining a high level of service availability is important. This makes fault tolerance an important issue. In general the failed connections need to be rerouted. After a link or node failure, alternate paths for restoration of the failed connections may exist only if the network is reconfigured. In addition to link or node failure scenarios, connection rerouting or network reconfiguration may also prove helpful for accommodating new requests which may otherwise be blocked. Since connections on backbone optical networks, have longer call durations, it is crucial to accommodate new blocked requests through alternate means, instead of blocking them till existing connections terminate and make a path available. These situations make network reconfiguration important. Since most connections plying on todays backbone networks are high data rate connections, it is critical that the connections have minimal disruption times during network reconfiguration. In this paper, we propose a methodology for minimizing the disruption time and the number of disruptions in the network during connection rerouting.