Failure detection for secure optical networks

Network security has become a very sensitive and important topic for manufacturers and network operators. In opaque optical networks, fault management deals with detection and isolation of faults based on the alarms received from the network components. In WDM networks, faults are difficult to identify due to the huge quantity of alarms generated because of the high number of channels involved in a single fault. In transparent optical networks, where no O/E/O conversion takes place, detecting and isolating faults becomes even more complex, since the optical signal is not regenerated and, therefore, the information reaching the manager is more limited. We define failure management as the prevention of, detection of, and reaction against failures (faults and attacks). Besides faults (accidental interruptions), optical networks can also be subject to attacks (intentional interruptions which can be performed by service disruption or eavesdropping). The paper presents in detail the techniques and methods of fault management. In addition, it covers the challenges associated with failure management in transparent optical networks.