| 摘要 |
PROBLEM TO BE SOLVED: To provide a communication mode switching and controlling method, capable of performing voice transmission to another ground, using the same communication channel from a data communicating state. SOLUTION: When a user A who is in the middle of performing center end type data communication notifies the address of a user B and makes a transmission request, an ISP-A7 solves the address of an ISP-B17 from the address of the user B, notifies the ISP-B17 of the address of the user B, the ISP-B17 refers to the address information of the user B, makes a request for an incoming call to the user B, the ISP-A7 and the ISP-B17 request the users A and B to switch communication modes and connect the input/output of the communication channel of the users A and B to the input/output of a communication channel formed between centers, and the users A and B are switched to end-to-end type voice communication. |
