Abstract: A communication system that improves operation and maintenance and controls communication efficiently. A supervisory signal sending control section controls the sending of a supervisory signal for having supervisory control of optical communication and a drive supervisory signal for controlling the driving of an optical fiber amplifier for performing optical amplification by using a non-linear optical phenomenon in an optical fiber. A sending stop section receives a stop signal and stops the sending of the drive supervisory signal. A drive control section receives the drive supervisory signal and controls the driving of the optical fiber amplifier. A stop signal sending section sends the stop signal to a sending unit after the optical fiber amplifier being driven.