Knowledge based path set up and spare capacity assignment for

Abstract

In a telecommunications network having a plurality of intelligent nodes interconnected by multiple communication channels, alternate paths and spare channels are set up for restoring traffic disrupted by failure to one or more of the communications channels. The alternate paths may be set up irrespective of the number of custodial node pairs, also referred to as leader/follower or sender/chooser pairs, that could simultaneously be involved in the restoration operation. The interconnected nodes have bi-directional working and/or spare channels. There is stored at each node in the network participating in the recovery operation a spare channel manifest for each of the leader/follower combinations. The first end node, or leader node, of every identified failed channel initiates a request message for each disrupted working channel to set up an alternate path. Spare channels are assigned to the alternate path so that, with the help of intermediate helper nodes, the request message, guided by the spare channel manifests, is sent to the second end node, or follower node, of the failed channel. An acknowledgement is sent by the follower node back to the leader node on the same path that the request message travelled on. The spare channel manifests are suitably configured to realize desired levels of restoration under various scenarios of failures in the network and are modified as warranted to account for changes in the network.