Abstract—Energy aware routing with restoration is of much importance for the network to enhance reliability as the relatively concentrated traffic makes the network vulnerable to link failures and sudden traffic bursts after energy saving. For restoration, each request has an active path and a link disjoint backup path. With sufficient path routing knowledge, backup paths can be shared for bandwidth efficiency. This is possible in Software Defined Networks (SDNs) owing to the centralized controller which can collect global information. In this paper, we first combine energy saving with restoration and address the problem called Restorable Energy Aware Routing with Backup Sharing (REAR-BS) in SDNs during off-peak hours when backup sharing is allowed. We formulate a nonlinear integer programming model to minimize the number of used links while putting idle ones to sleep under constraints of maximum link utilization and restoration. We rewrite it as a linear model and give a lower bound for this NP-hard problem. Then, we design a heuristic algorithm called Green Restorable Algorithm (GreRA) to tackle this problem. Extensive simulation results on real and synthetic topologies and traffic demands show the effectiveness of GreRA when compared to CPLEX solutions, shortest path routing with restoration and lower bound.

Index Terms—Energy aware routing, restoration, link disjoint, nonlinear integer programming, reliability, backup path.

Cite: Rui Wang, SuixiangGao, Wenguo Yang, and Zhipeng Jiang, "Restorable Energy Aware Routing with Backup Sharing in Software Defined Networks," Journal of Communications, vol. 10, no. 8, pp. 551-561, 2015. Doi: 10.12720/jcm.10.8.551-561