This invention solves the problem that, if a loss of signal or other anomaly occurs on a line side, intermittent problems occur in a signal outputted to a client side, resulting in trouble with subsequent signal processing. This optical-transceiver control circuit comprises a signal-generating means for generating a dummy signal that has approximately the same characteristics as an electrical signal generated from an optical signal inputted to an optical transceiver, a switching means for receiving an electrical signal and selecting and outputting either the received electrical signal or the generated dummy signal, and a controlling means for changing the signal selected by the switching means from the electrical signal to the dummy signal if a notification indicating an anomaly in the optical signal is inputted.
