A telephone set and an information terminal are connected by a packet switched network. The information terminal has a control target list in which a predetermined telephone set information is stored, and a terminal controller. The terminal controller generates, based on an instruction from a user, a control command in which an instruction related to multimedia phone communication is recorded, and sends that command to the predetermined telephone set. The predetermined telephone set has a terminal list storing information about the information terminal, and a telephone controller. The telephone controller generates, based on the control command received from the information terminal, a call control command for performing multimedia phone communication with another telephone set on the packet switched network, and sends that command to the other telephone set.