Flow Entry Sharing in Protection Design for Software Defined Networks

Xiaoning Zhang, Shui Yu, Zhichao Xu, Yichao Li, Zijing Cheng, Wanlei Zhou

Abstract: In Software Defined Networks (SDN), though we can design protection mechanism to enable fast recovery against a single link failure, it requires proactively installing a large number of flow entries in switches on working paths and backup paths. However, these additional flow entries in a SDN switch may exhaust Ternary Content Addressable Memory (TCAM) which is limited in size since it is expensive and power hungry. Accordingly, it is emergent to design a new protection technology to minimize flow entry occupation. To this end, we leverage flow entry sharing in SDN protection to solve this problem. We first present the problem as an ILP (Integer Linear Programming) model, and then design a greedy based heuristic algorithm named Flow Entry Sharing Protection (FESP). Extensive simulation results show that compared with the previous SDN protection algorithms, FESP reduces 28.31% flow entries and 27.65% link bandwidth in average.