A communication system comprising: a mobile station capable of connecting to an IP access network following Internet protocols via either a first radio access network that supports services on an IP multimedia subsystem following Internet protocols or a second radio access network that does not support the services on the IP multimedia subsystem including a voice call using SIP and a Short Message Service using IP; and an exchange (210, 220) capable of communicating with the IP multimedia subsystem, wherein the exchange includes an information notification unit (213, 223) configured to transmit service non-supporting information to the mobile station, the service non-supporting information indicating that the second radio access network does not support any of the services, the mobile station includes a bearer establishment unit configured to transmit a bearer establishment request to the IP access network, the bearer establishment request requesting establishment of a bearer that is a logical communication path between the mobile station and a gateway device included in the IP access network, and an information receiving unit configured to receive the service non-supporting information from the exchange via the second radio access network, and the bearer establishment unit is configured to stop the transmission of the bearer establishment request via the second radio access network when the information receiving unit receives the service non-supporting information. a mobile station capable of connecting to an IP access network following Internet protocols via either a first radio access network that supports services on an IP multimedia subsystem following Internet protocols or a second radio access network that does not support the services on the IP multimedia subsystem including a voice call using SIP and a Short Message Service using IP; and an exchange (210, 220) capable of communicating with the IP multimedia subsystem, wherein the exchange includes an information notification unit (213, 223) configured to transmit service non-supporting information to the mobile station, the service non-supporting information indicating that the second radio access network does not support any of the services, the mobile station includes a bearer establishment unit configured to transmit a bearer establishment request to the IP access network, the bearer establishment request requesting establishment of a bearer that is a logical communication path between the mobile station and a gateway device included in the IP access network, and an information receiving unit configured to receive the service non-supporting information from the exchange via the second radio access network, and a bearer establishment unit configured to transmit a bearer establishment request to the IP access network, the bearer establishment request requesting establishment of a bearer that is a logical communication path between the mobile station and a gateway device included in the IP access network, and an information receiving unit configured to receive the service non-supporting information from the exchange via the second radio access network, and the bearer establishment unit is configured to stop the transmission of the bearer establishment request via the second radio access network when the information receiving unit receives the service non-supporting information.