Fault localization for optical networks
Carmen Mas Machuca, O. Crochat, Jean‐Yves Le Boudec · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 1998
A single failure in a communication network may trigger many alarms. When the communication network uses optical fibers as a transmission medium and increases its capacity by using Wavelength Division Multiplexing and Space Division Multiplexing, the number of alarms and the difficulty to locate the failure are considerably higher. In this case, a single failure may interrupt several channels so that the quality of lost information is larger. We propose an alarm filtering algorithm for the fault management of an optical network that supports multiple failures and works in the presence of passive elements, that is, network elements which may fail but never generate an alarm (e.g. optical fibers). Our algorithm avoids the use of failure probabilities because they are difficult to estimate and it does not need a global knowledge of the network topology. Moreover it also tolerates alarm losses. The algorithm results in the presentation to the human manager of a list of faults which may have caused the observed alarms. The alarm filtering problem is defined and formalized at the level of abstraction for devising the Alarm Filtering Algorithm. The algorithm is then applied to the optical network of the ACTS COBNET project.