p-Cycle based dual failure recovery in WDM mesh networks

We propose a new optimization solution method for the design of dual failure survivable p-cycle based WDM mesh networks that guarantee a quantified service availability under different dual failure probability distributions. Nowadays, network providers are facing the challenge of meeting the specifications of service-level agreements (SLAs) with their corporative customers. Therefore, it is of interest to understand and quantify the service availability in order to allow a comparison of the delivered qualities of services with the guaranteed ones, and thus to offer safe SLAs and competitive services. We therefore propose to investigate further the relationship between network physical topologies and the required amount of spare capacity to attain an optimized dual failure recovery level. In order to properly address the scalability issue related to the offline enumeration of the candidate p-cycles, we develop a solution method based on column generation techniques where a very limited number of valued p-cycles are dynamically generated during the optimization process. Depending on the network connectivity, the results show that a spare capacity investment of 2.3 to 5.2 times the amount of protected capacity is necessary, in order to guarantee a 100% dual failure restorability, when using p-cycles in survivable mesh networks.