Energy aware management of resilient networks with shared protection

This paper addresses the problem of minimizing the energy consumption of IP networks. As traffic demands vary over time, energy savings are achieved by adapting traffic routing and node and link sleeping patterns while guaranteeing QoS and survivability requirements. Network survivability is based on shared protection for single link failures. The optimization framework considers a set of time intervals and, to guarantee network stability, inter-period limitations are imposed. Both exact and heuristic methods are proposed. Results obtained with realistic networks operated with flow-based routing protocols show that i) up to 60% of the energy savings can be achieved without negatively affecting the network resiliency and that ii) the shared protection scheme better exploits backup capacity than the dedicate protection one.