A second network which communicates with a communication system for providing access to a network other than a first network, via the second network, to a wireless terminal on which an identification number for accessing the first network is stored, configured to: receive a connection initiation request on C-plane from the wireless terminal to send the connection initiation request to the communication system, receive a gateway ID of a gateway on U-plane to the network connected to the second network, selected on the communication system based on a network ID of the second network, in response to the connection initiation request, wherein the gateway is within a third network other than the first network, and establish a communication path between the gateway on U-plane designated by the gateway ID.