Patent ID: 8432792

Claim:
A protection path bandwidth control method for a ring network in which a plurality of node apparatuses are connected in a ring configuration, and in which, to provide protection for a working path passing through said ring network, a protection path is provided that cycles around said ring network and that transports a signal in a direction opposite to a signal transporting direction of said working path and, in the event of a failure of said working path, a node apparatus adjacent to said failure loops back the signal flowing on said working path onto said protection path, wherein at each of said node apparatuses, a maximum total bandwidth value, which represents the largest value among per-link total values of bandwidths that a plurality of working paths use on respective links connecting between said respective node apparatuses, is stored in a prescribed storing unit as an allowable bandwidth for a shared path provided to be shared among said plurality of working paths, as a protection path to backup said plurality of working paths, at each of said node apparatuses, the bandwidth of traffic flowing on said protection path is controlled in accordance with said allowable bandwidth, and said protection path bandwidth control method comprising: receiving a working path setup message requesting to set up a new working path that passes through one of said node apparatuses from one of adjacent node apparatuses adjacent to said one of node apparatus; transmitting said working path setup message to the other one of said adjacent node apparatuses adjacent to said one of node apparatus; calculating a sum of bandwidths that an existing working path and said new working path respectively use on a link that connects between said one of node apparatus and said adjacent node apparatus and through which said new working path passes; and updating said received working path setup message so as to include said sum as tentative maximum bandwidth information into said working path setup message for transmission to said other adjacent node apparatus when said sum calculated by said bandwidth calculating unit is larger than the bandwidth indicated by the tentative maximum bandwidth information contained in said received working path setup message.