Alternate route calculation manner and the device, the alternate route calculation server, the alternate route calculation router, and alternate route calculation

摘要

PROBLEM TO BE SOLVED: To establish a route by relaxing requirements even under any network environment and even when the alternate route cannot be obtained.;SOLUTION: An alternate route calculation apparatus disclosed herein includes: a graph generating means that generates a graph of route calculation objects by eliminating nodes through which a primary path connecting an ingress node and an egress node passes on the basis of received connection information when an End-to-End alternate route is calculated with respect to the primary path; a route calculation means for applying route calculation to the graph; and a solution output means for outputting the route, and the graph generating means includes a means for re-generating the graph by tracing a leaf side node back to an upper stream node in the unit of the node and allows the route calculation means to execute the route calculation when the route calculation means cannot establish the alternate route not duplicated with the primary path.;COPYRIGHT: (C)2007,JPO&INPIT