Energy-Aware Routing Algorithms in Software-Defined Networks

The feature of centralized network control logic in Software-Defined Networks (SDNs) paves a way for green energy saving. Router power consumption attracts a wide spread attention in terms of energy saving. Most research on it is at component level or link level, i.e. each router is independent of energy saving. In this paper, we study global power management at network level by rerouting traffic through different paths to adjust the workload of links when the network is relatively idle. We construct the expand network topology according to routers' connection. A 0-1 integer linear programming model is formulated to minimize the power of integrated chassis and line-cards that are used while putting idle ones to sleep under constraints of link utilization and packet delay. We proposed two algorithms to solve this problem: alternative greedy algorithm and global greedy algorithm. For comparison, we also use Cplex method just as GreenTe does since GreenTe is state of the art global traffic engineering mechanism. Simulation results on synthetic topologies and real topology of CERNET show the effectiveness of our algorithms.