Calling method, calling terminal and calling system through information and communication network

A calling terminal capable of establishing a call in packet communication through a calling path which is set in the information and communication network, and of serving as a transmitting terminal or a receiving terminal, the calling terminal comprising:

• path searching means for searching an available calling path with cheaper rate than that of a calling path which has been established, during the call established between the transmitting terminal and the receiving terminal, and
• path switching means for switching, when the calling path with cheaper rate than that of the established calling path is searched by the path searching means, the established calling path to the searched calling path.

A calling system capable of establishing a call in packet communication through a calling path which is set in the information and communication network, and of serving as a transmitting terminal or a receiving terminal, the calling system comprising:

• a call relay device by which a plurality of calling paths can be set in the information and communication network;
• a path exchanging device responsive to a call from the transmitting terminal to the receiving terminal for establishing a calling path which is selected from the plurality of calling paths by the call relay device and for switching the calling path to a calling path with cheap rate when the calling path which has been established and other calling paths are monitored and a calling path with cheaper rate than that of the established calling path becomes available, and a call charging device for charging a rate in response to the calling path to at least one of the transmitting terminal and the receiving terminal.