A Multipath Routing Algorithm for Degraded-Bandwidth Services under Availability Constraint in WDM Networks

In this paper, we propose a multipath routing algorithm, which uses inverse multiplexing technique, to provision reliable degrade-services over NGS/WDM networks. Compared with previous models like effective bandwidth and fractional bandwidth reliable multipath mechanisms, our proposed service model could contribute concreteness to service level contracts such that customers´ tradeoff between bandwidth and availability can be quantitative by jointly considering two metrics: workable traffic volume and availability. Since the RWA problem with availability constraint is known as NP-hard, there might not be any efficient algorithms to solve the provisioning problem in our model. Therefore, we devise a load-balance traffic engineering algorithm to minimize blocking probability when traffic request is dynamic.