Optimization Strategy of OpenFlow Flow Table Storage Based on the Idea of xe2x80x9cBetweenness Centralityxe2x80x9d Since the advent of the Internet, its scale has expanded rapidly. Traditional network architecture is increasingly difficult to support this huge business. At this time, the clean slate team at Stanford University in the United States defined a new network architecture, SDN (Software Defined Network). The introduction of this network architecture has brought about tremendous changes in the development of todayxe2x80x99s networks. The separation of control layer from data layer through SDN enables network administrators to plan the network programmatically without changing network devices, realizing flexible configuration of network devices and fast forwarding of data flows. The controller sends the flow table down to the switch, and the data flow is forwarded through matching flow table items. However, the current flow table resources of the SDN switch are very limited. Therefore, this paper studies the technology of the latest SDN Flow table optimization at home and abroad, proposes an efficient optimization scheme of Flow table item on the betweenness centrality through the main road selection algorithm, and realizes related applications by setting up experimental topology.

Modeling and optimization of packet forwarding performance in softwaredefined WAN Abstract   As a novel network paradigm, SoftwareDefined Networking (SDN) offers numerous benefits for widearea networks (WAN), like promoting application performance and reducing deployment costs. However, it also comes along with an inherent penalty to essential network performance such as packet forwarding delay, primarily due to the involvement of logically centralized controllers. This paper is motivated to provide an accurate queueing system of packet forwarding performance in softwaredefined WAN based on modeling its controller cluster and OpenFlow switches. In particular, we approximate the packetin message processing of the controller cluster as an     M  xe2x88x95  M  xe2x88x95  n     queue based on the derivation of its message arrival process. Meanwhile, we characterize the packet processing of an OpenFlow switch as an     M  xe2x88x95  G  xe2x88x95  1     queue after taking an insight into its packet switching process. As a further step, we build an optimization model of controller cluster deployments to obtain the optimal number of controllers in the cluster. Finally, our proposed queueing model of SDN controller cluster is evaluated with the prevalent benchmark OFsuite_Performance by experiments, and their results indicate that our proposed model provides a more accurate approximation of controller cluster performance. Furthermore, we perform numerical analysis on packet forwarding delay and solve the optimal number of controllers for different varying parameters, which offer effective guidelines for softwaredefined WAN deployments.