Remote supervisory system for network elements.

摘要

Disclosed is a remote supervisory system in which slave supervisory apparatus (S-SV) for supervising network elements can be polled from a master supervisory apparatus (M-SV), and yet each S-SV is able to send an alarm signal to the M-SV at any appropriate time. In this system, a first transmission path connected to the M-SV is connected via a switch to a second transmission path leading from each S-SV. The switch is controlled in accordance with the presence of a signal on the first transmission path and also with the presence of a signal on the second transmission path.