The Research and Implementation of SDN Switch's Flow Table Optimization

Abstract

Software Defined Networking (SDN) is a new network architecture, separating the control and data planes from closed system of traditional network, bringing many advantages such as good controllability and flexibility. It's biggest superiority is loosely coupled between control plane and data plane. However, there are lots of problems in this architecture and the bottleneck problem is the network's performance. Existing OpenFlow protocol based flow expiry mechanisms relys on a fixed timeout after which the switch proactively removes the flow entries from its flow table which may cause unnecessary flow table occupation. Therefore, in this paper, a strategy of dynamically adjusting timeout time is proposed and the program is implemented. It can dynamically adjust the timeout time according to the actual situation of equipment and data flow, and can better adapt to the network with different data flows. The experiment shows that the strategy can improve the network's performance greatly and the mechanism designed in this paper is very effective.