The multifunction machine which functions as a telephone terminal equipment requests a connection to an Internet terminal equipment evoked from a transfer operation while the multifunction machine is connected to a telephone terminal equipment. The multifunction machine can be connected to the Internet terminal equipment if this Internet terminal equipment responds to the request. After the multifunction machine is connected to the both terminal equipments, an audio call among three parties; the multifunction machine, the telephone and Internet terminal equipments can be achieved with input/output sound corresponding to audio signals input/output between the multifunction machine and the respective terminal equipments from a telephone transmitter/receiver.