Methods of determining the performance and the advanced failure of an optical communication channel. Performance of an optical communication channel may be determined by receiving light signals, generating a measure of an average received optical power in the received light signals and monitoring changes in the measure of the average received optical power. Advanced failure of an optical communication channel may be determined by transmitting a light signal at one end of the optical communication channel, propagating the light signal in an optical transmission medium, receiving the light signal at an opposite end of the optical communication channel, generating an electrical signal responsive to the receiving of the light signal. determining a measure of an average received optical power in the received light signal in response to the electrical signal, and monitoring changes in the measure of the average received optical power.