A Novel Framework of Fast and Unambiguous Link Failure Localization via Monitoring Trails

The concept of monitoring trail (m-trail) has been proposed for achieving Fast and Unambiguous Link-failure Localization (FULL) in all-optical WDM (Wavelength Division Multiplexing) mesh networks. Previous studies on m-trails assumed the presence of alarm dissemination at each node such that a remote routing entity can collect the flooded alarm bits and form the alarm code to localize the failed link. This obviously leads to additional delay and extra control complexity in the electronic domain process. In this paper, we propose a novel framework based on m-trails for FULL, aiming at avoiding any possible alarm flooding and electronic domain mechanism such that each individual monitoring node (MN) can localize a single link failure according to locally available alarm bits. To save the supervisory wavelength-links, the proposed framework enables that the status of an m-trail can be monitored by multiple MNs along the m-trail by tapping the optical supervisory signal, rather than only by the destination node of the m-trail. An ILP (Integer Linear Program) is formulated and solved in a case study to verify the ILP and show the effectiveness of the proposed framework. We demonstrate that the status sharing among MNs of a common m-trail can effectively suppress the increase of supervisory wavelength-links as the number of MNs increases.