Research On Scalability Of OpenFlow Control Plane

Software defined network(SDN)is a new network architecture proposed in recent years,which provides a more intelligent,more flexible and more managerial network compared to the traditional network.Because of the advantages of SDN,especially its programmable characteristic,it has been gradually deployed in the campus networks,enterprise networks,data centers and wide area networks(WAN).It has brought great development prospects to the next generation network.This paper aims to study the scalability of OpenFlow control plane in SDN,including the placement of OpenFlow controllers and the global view of control plane.This paper mainly completed the following work:1)Studied the number and placement of OpenFlow controllers in the WANfor the time delay of the whole network.In the first part of this paper,an improved algorithm has been proposedto compute the optimal placement of the controller.In the wide area networks,this algorithm can reduce the transmission delay of the whole network.2)Proposed a method based on the WAN to maintain the global view of the network.Using this method,the communications between the OpenFlow controllers could be used to complete the global view of the network without increasing the complexity of the control plane or adding additional facilities.At the same time,the matching rules of communication are designed to ensure the availability of the system.In our design of the SDN system,the whole network delay can be further reduced with the proposed improved OpenFlow controller placement algorithm.At the end of the paper,a series topologies on the Zoo Topology are used to simulate the improved controller placement algorithm and test its performance.The results show that the improved OpenFlow controller placement algorithm and the maintenance method of global view have good performance in the propagation delay,and have important reference value in the process of SDN network deployment.