| 摘要 |
PURPOSE:To prevent the simultaneous start processing at a fault by bringing an outgoing trunk (OGT) after restoring the OGT when a caller hooks on at a fault of a PCM system and bringing an incoming trunk (ICT) into the ring-off state when a called party hooks on. CONSTITUTION:If a fault takes place in the PCM system, the OGT not busy in the PCM system is brought into the closing state and the ICT is brought into no call state and the state of a caller and a called party of a telephone set in busy state is supervised. Further, when the caller hooks on, the OGT is restored and then brought into the block state, and when the called party is hooked on, the ICT is brought into the ring-off state. Thus, the telephone state in busy state is brought into normal state by hooh-on, the OGT group connected to the PCM system in fault is blocked and the ICT group is brought into no calling state. |
