Included are a network information database for storing the statistical information collected from a router, a user request processing unit for accepting and processing a flow forwarding request from a user terminal connected to the network, a route control unit for searching for a route corresponding to the request from the user terminal by referring to the network information database, a load sharing control unit for executing such a load sharing process as to generate router setting information for sharing a transmission load of the network by referring to the network information database, and a router control unit for setting a router based on the route information determined by the route control unit and on the router setting information generated by the load sharing control unit.