Patent ID: 8898335

Claim:
An apparatus for calculating a plurality of end-to-end paths each having a given bandwidth and communicably connecting two terminal nodes in a communication network divided into a plurality of areas, the apparatus comprising: a memory for storing information on the plurality of areas; and a processor to: select, from among the plurality of areas, a first sequence of passage areas to be traversed by a first end-to-end path and a second sequence of passage areas to be traversed by a second end-to-end path, based on the information on the plurality of areas, select, from among the first sequence of passage areas, multi-path passing areas each defined as an area to be traversed by both the first and second end-to-end paths, calculate two or more intra-area paths for each of the multi-path passage areas, each of the two or more intra-area paths being defined as a communication path that communicably connects two different boundary nodes within an area and has the given bandwidth, the two or more intra-area paths being calculated by a node in the each of the multi-path passage areas based on path calculation requesting message that is transferred along the first sequence of passage areas, the path calculation requesting message including bandwidth information indicating the given bandwidth, passage area information identifying the first sequence of passage areas, and multi-path passage area information identifying the multi-path passage areas, select, for each of the multi-path passage areas, first and second intra-area path from among the calculated two or more intra-area paths, and determine the first and second end-to-end paths so that the first and second end-to-end paths include the selected first and second intra-area paths, respectively, and so that each of the first and second end-to-end paths has the given bandwidth.