T-trail: link failure monitoring in software-defined optical networks

Monitoring trail (m-trail) provides a striking mechanism for fast and unambiguous link failure localization in all-optical networks. However, allocating dedicated supervisory lightpaths (m-trail) undoubtedly increases total network cost. Accordingly, how to maximally reduce monitoring cost in an optical network is an important issue. To this end, we propose a concept of traffic trail (t-trail) that uses traffic lightpaths, instead of dedicated supervisory lightpaths, to localize a single link failure in the context of a software-defined optical network (SDON). The central controller of an SDON collects routing information of all t-trails in the network. Thus, any link failure can be localized according to the ON–OFF status of the traversing t-trails. We first formulate the problem as an integer linear programming (ILP) model. Since the ILP is not feasible for solving the problem in large-size networks, an efficient heuristic algorithm t-trail allocation (TTA) is proposed to address it. We conduct extensive simulations to evaluate the performance of TTA. The results show that compared with the existing m-trail schemes, TTA can reduce total costs by 20.91% on average.