Channel changing method

The present invention proposes a channel having a controller for converting a first information processor, the second switch and the communication network information processor (e.g., the ISDN), can facilitate communication error occurs in the network, rapidly changing channels. If the communication between the first and second information processor fails, it notifies the first information processor switches the communication channel currently used, or line terminals (telephone number) to be converted to another. Thus, the current call switching center, through a communication channel newly elected station or line (telephone number) communication is restored after release of the first information processor, such that the communication between the two proceed.