Communication system control apparatus, control method, and program

A communication system control method, comprising:

• by a computer, extracting a second switch adjacent to a first switch to be terminated in a communication system including a plurality of switches having a predetermined topology;
• calculating a shortest path tree including the second switch as a root, based on a topology obtained by excluding the first switch from the predetermined topology, wherein the determining comprises determining a path from the second switch to the fourth switch based on the shortest path tree;
• extracting a flow transferred to the first switch after the second switch from a plurality of flows passing through the communication system;
• determining, assuming that, among the plurality of switches, switches located at start and end nodes of the flow are third and fourth switches, respectively, a bypass path from the second switch to the fourth switch, based on a topology obtained by excluding the first switch from the predetermined topology;
• connecting a path from the third switch to the second switch in an initial path of the flow and the bypass path determined in the determining to generate a new path of the flow, and
• determining if the new path includes a redundant switch wherein if the switches before and after the second switch are an identical switch in the new path, eliminating a redundant path between the second switch and the identical switch.

A non-transitory computer readable medium recorded thereon a program causing a computer to execute a method comprising:

• extracting a second switch adjacent to a first switch to be terminated in a communication system including a plurality of switches having a predetermined topology;
• causing the computer to further execute calculating a shortest path tree including the second switch as a root, based on a topology obtained by excluding the first switch from the predetermined topology,
• extracting a flow transferred to the first switch after the second switch from a plurality of flows passing through the communication system;
• determining, assuming that, among the plurality of switches, switches located at start and end nodes of the flow are third and fourth switches, respectively, a bypass path from the second switch to the fourth switch, based on a topology obtained by excluding the first switch from the predetermined topology;
• connecting a path from the third switch to the second switch in an initial path of the flow and the bypass path determined in the determining to generate a new path of the flow;
• and
• determining if the new path includes a redundant switch wherein if the switches before and after the second switch are an identical switch in the new path, eliminating a redundant path between the second switch and the identical switch
• wherein the determining comprises determining a path from the second switch to the fourth switch based on the shortest path tree.