Limited-perimeter vector matching fault-localisation protocol for transparent all-optical communication networks

A novel fault-localisation protocol is constructed based on the principles of distributed control and management mechanisms. The proposed protocol has high scalability and speed, but at the cost of increased computational complexity. To provide the maximum level of transparency, the protocol skips any optical power monitoring or spectrum analysis at the intermediate nodes of established lightpaths. Moreover, to narrow down the associated time and space complexities, it restricts the fault-localisation area to a small area called limited-perimeter. These functions are implemented by means of five phases, namely pausing, flooding, multicasting, matching, and concluding. Although the protocol has been developed to pinpoint single failures, it could track down multiple failures that occur in nonoverlapped limited-perimeters. To evaluate the performance of the proposed method, time and space complexities are calculated and compared with a counterpart protocol that does not limit the fault-localisation area.