High Speed Serial Link In-Band Lane Fail Over for RAS and Power Management

A system and method provide a communications link having a plurality of lanes, and an in-band, real-time physical layer protocol that keeps all lanes on-line, while failing lanes are removed, for continuous service during fail over operations. Lane status is monitored real-time at the physical layer receiver, where link error rate, per lane error performance, and other channel metrics are known. If a lane failure is established, a single round trip request/acknowledge protocol exchange with the remote port completes the fail over. If a failing lane meets an acceptable performance level, it remains on-line during the round trip exchange, resulting in uninterrupted link service. Lanes may be brought in or out of service to meet reliability, availability, and power consumption goals.