On identifying SRLG failures in all-optical networks

Fast and unambiguous failure localization (UFL) is a desired feature in all-optical networks in order to provision high availability services. To save monitoring resources for signalling-free UFL, the paper studies a novel algorithm to localize any SRLG failure via monitoring-trails (m-trails) together with the working lightpaths. The feasibility conditions on the proposed m-trail allocation problem are discussed while different m-trail sharing strategies are introduced and compared via simulation. The problem of selecting an optimal set of working lightpaths is shown to be NP-complete and the simulation results verify the proposed algorithm with respect to monitoring resource consumption and running time.