An apparatus stores connection information indicating connection relationship among topological structures in a network, in which first-type topological structures are coupled to second-type topological structures. The apparatus stores first transfer-patterns each indicating a combination of input and output ports for performing all-to-all communication without path conflict in each of the first-type topological structures, and second transfer-patterns each indicating a combination of input and output ports for performing all-to-all communication without path conflict in each of the second-type topological structures. The apparatus identifies paths from transmission sources to transmission destinations for a combination of the first and second transfer-patterns, and determines, based on the identified paths, a transfer-pattern with which to perform all-to-all communication without path conflict from the transmission sources to the transmission destinations, and determines output ports in each of the first- and second-type topological structures, corresponding to the identified paths.