A radio terminal or gateway capable of executing the AV/C protocol on the datalink protocol which starts communications after setting up a logical channel on a radio network is disclosed. The radio terminal or gateway transfers data packets according to the stored correspondence information among the protocol identifier, the channel identifier that is set up for the radio terminal or gateway, and the channel identifier that is set up for a correspondent radio terminal or gateway, where the correspondence information is obtained through an exchange of signaling packets containing the channel identifier indicating a logical channel that is set up for transferring the data packets and the protocol identifier indicating the AV control protocol.