Communications system having a host exchange and a mate exchange and a method for managing maintenance state of subscriber accommodated in the mate exchange

摘要

A communications system includes a host-exchange system having a host exchange, a mate-exchange system having a mate exchange accommodating a mate-exchange subscriber terminal, and a communications medium connecting the host-exchange system and the mate-exchange system together. The mate- exchange system includes a first unit for collecting maintenance information as to whether or not the mate-exchange subscriber terminal is operable, and a second unit for sending the maintenance information to the host-exchange system via a transmission range allotted to the mate- exchange subscriber terminal on the communications medium. The host- exchange system includes a third unit for monitoring a state of the mate- exchange subscriber terminal on the basis of the maintenance information from the second unit and for controlling a call addressed to the mate- exchange subscriber terminal.