Disclosed is a technique for reporting the IP address of a UE using a response message to a device trigger. A control message receiving unit receives, from a network, a control message generated based on a trigger request message transmitted from the predetermined communication device for requesting the transmission of the control message to a communication terminal. A determining unit determines whether to perform communication with the predetermined communication device using an IP packet. A connection management unit acquires an IP address allocated to an IP connection used in communication with the predetermined communication device when determining to perform the communication using the IP packet at the time of receiving the control message at the control message receiving unit. A response message transmitting unit transmits a response message to the control message to the network, where the response message includes the IP address acquired by the connection management unit.