摘要 |
To realize a handover in which a gateway connecting to the access networks using different protocols is an anchor. In a communication system, the gateway holds a service identifier management table for converting a service identifier of different kind with the protocol into a PDN identifier, and at the time of handover, specifies a session to be held with the user identifier and the PDN identifier, selects the same PDN connected to the movement source, and reassigns the same IP address that has been already assigned at the movement source. |