COMMUNICATION SYSTEM

To be able to check, from a remote location, a switching result of a power supply route, this communication system comprises: a plurality of terminal stations which each have a function of supplying power to a power supply path; a branching device which switches the power supply route, which includes a power supply path; and a monitoring device which, in response to one of the plurality of terminal stations transmitting to the branching device a switching signal specifying the power supply route, compares the voltages of the power supplied to the power supply paths respectively observed by the plurality of terminal stations, before and after transmission of the switching signal, and which, with the compared power supply voltages each having fluctuated by a first threshold or more, determines a switching result of the power supply route in the branching device.