Relaying device, audio communication system, program and relaying method

An audio communication system comprising:

• a relaying device and a plurality of terminal devices communicating mutually via a communication network;
• wherein
• the relaying device comprises,
• a network communication unit for being connected with a communication network and communicating with a plurality of terminal devices via the communication network;
• a control unit for establishing a communication session when a calling audio signal is received from the first terminal device, wherein the communication session is participated by the first terminal device and a terminal device of a communication partner designated by the calling audio signal, and transferring the audio signal mutually between the terminal devices participating in the communication session;
• a priority information storage unit for storing priority information of the communication session;
• wherein
• the control unit includes a priority determining unit for determining the priority of the existing communication session and a new communication session which should be established by the calling audio signal on the basis of the priority information on receiving the calling audio signal designating the terminal device participating in the existing communication session as the communication partner;
• the control unit makes the terminal device participating in the existing communication session resign from the existing communication session and participate in the new communication session in the case the priority of the new communication session is higher than that of the existing communication session;
• and
• the terminal device comprises a terminal network communication unit communicating with the relaying device via the communication network and a terminal control unit transmitting the audio signal to which the information designating the terminal device of the communication partner is attached to the relaying device using the terminal network communication unit.

A relaying method for the control unit of the relaying device which comprises a network communication unit communicating with a plurality of terminal devices via the communication network and a storage unit storing the priority information of the communication session by a plurality of the terminal devices performing a first procedure for establishing a communication session when a calling audio signal is received from the first terminal device, wherein the communication session is participated by the first terminal device and a terminal device of a communication partner designated by the calling audio signal, and transferring the audio signal mutually between the terminal devices participating in the communication session:

• wherein
• the first procedure comprises,
• a second procedure for determining the priority of the existing communication session and a new communication session which should be established by the calling audio signal on the basis of the priority information on receiving the calling audio signal designating the terminal device participating in the existing communication session as the communication partner;
• and
• a third procedure for making the terminal device participating in the existing communication session resign from the existing communication session and participate in the new communication session in the case the priority of the new communication session is higher than that of the existing communication session.