Patent ID: 7561563

Claim:
A communication path setting method of setting a communication path between a first telephone terminal system connected to a packet network and a second telephone terminal system connected to a circuit switching network and said circuit switching network, wherein said packet network and said circuit switching network are connected through a gateway device which performs predetermined signal conversion, said second telephone terminal system being provided with a first port connected to said packet network for performing conversion between voice band signals and packet signals, and a second port connected to said circuit switching network for transmitting and receiving voice band signals, said first port is configured to pass voice band signals to said circuit switching network by bypassing when said first port is not working, said communication path setting method comprising: a step (A) in which said first control device receives a connection request for connecting said second telephone terminal system from said first telephone terminal system; a step (B) in which said first control device transmits said connection request to said second control device through said packet network; a step (C) in which said second control device determines whether or not said first port is operating in response to said connection request; a step (D) in which, when it is determined in said step (C) that said first port is not operating, said second control device sets said communication path through said packet network, said circuit switching network and said second port by the use of said gateway device; a step (E) in which said first control device determines, through said packet network, whether or not said second control device is operating in response to said connection request; and a step (F) in which, when it is determined in said step (E) that said second control device is not operating, said first control device sets said communication path through said packet network, said circuit switching network and said second port by the use of said gateway device; and wherein said second control device sets, in said step (D), said communication path by the use of said gateway device which is associated with said second control device; and wherein said first control device sets, in said step (F), said communication path by the use of said gateway device which is associated with said first control device.