| 摘要 |
<p>A working call controller 11 (12) changes its operating mode to a standby mode when it is not carrying out call processing at system switching for management, and to a transient working mode when it is carrying out call processing at system switching for the management to continue the call processing. A standby call controller 12 (11) changes its operating mode to a working mode when the other call controller 11 (12) enters the standby mode, and to a transient working mode when the other call controller 11 (12) enters the transient working mode. One of the call controllers 11 and 12 in the transient working mode, receiving the call control signal of a new call, carries out the call processing of the new call exclusively. <IMAGE></p> |
