| 摘要 |
PURPOSE:To shorten the waiting time until the connection of circuits, by transmitting transmission data to a calling terminal along with the reason for incapability of the circuit connection in case a line concentrator is incapable of the connection of circuits to a calling request of an end office device and then deciding a calling destination by the calling end office device on the basis of the above-mentioned reason for incapability. CONSTITUTION:When a calling request is given to a line concentrator CST11 from a terminal device T111, the CST11 sends a signaling frame 3 back to a calling end office device ST11. When the CST11 detects the incapability of connection, a connection incapability response CLN is set to the DATA of the frame 3 in the form of No and then transmitted to the device ST11. The ST11 performs the following processing, for example, in response to the connection incapability response No. That is, (a) no call is given to other line concentrators since it is considered that a calling subscriber performs a calling mistake, (b) the calling is continued to the line concentrator of another loop network by deciding that a power supply is missed, and (c) the calling is continued to the line concentrator. In such a case, the calling line concentrator becomes busy. In such a way, the undesired calling operations are suppressed to shorten the waiting time for a connection. |
