| 摘要 |
PROBLEM TO BE SOLVED: To provide a network controller that can inform a center terminal about a situation where the network controller cannot replay a call from the center terminal, because two B ISDN channels connected to the network control ler are busy. SOLUTION: Upon the receipt of a setup message, whose channel identifier indicates 'no channel', a line interface 5 informs an incoming call not-acceptable notice means 8 about the situation that two B channels are busy. The incoming call not-acceptable notice means 8 allows the line interface 5 to transmit a release end message denoting '#17 incoming user being busy' to the center terminal 1. Thus, the center terminal 1 can recognize the reason why the network controller 3 cannot replay, because the two B channels are busy, as is indicated by the received release end message denoting the '#17 incoming user being busy'.
|
