| 摘要 |
PURPOSE:To perform free connection between terminals having different protocols, while using advantages of a line exchange system, by providing a protocol conversion trunk. CONSTITUTION:When a terminal 11 performs a call, a line exchange 10 receives transmitted information and the number of opposing party through an interface circuit 30, sets a channel connecting the terminal 11 and an opposing terminal 14 in a switch 15 through the control of a control section 16 and informs the incoming of call to an interface 31. Before control circuits 32, 33 calls out the other party, the information relating to the protocol of each terminal is transmitted and received, whether or not both protocols are coincident is discriminated, and if no coincident, the control circuits 32, 33 transmit signals representing the end of communication and once open the channel. Then, the control circuit 32 transmits a signal as if it were retransmitted to the control section 16, and when it is received, the number of a protocol conversion trunk 34 is transmitted as the number of opposing party, the channel from the terminal 11 to the protocol conversion trunk 34 is set and the connection from a trunk 34 to the terminal 14 is done. |
