Optical path fault management in layered networks

A fault management technique for the optical path network employing WDM is proposed. Fault management is divided into optical path fault management and equipment fault management. The former always monitors the optical path and guarantees optical path transport performance through the network. The latter starts isolating the failed optical module after detecting the optical path failure. For robust optical path fault management, the bit error rate (BER) of the optical signal should be monitored. Realized by the bit interleaved parity technique, this can create effective fault management