SDN Controller Placement Optimization Technology Research And System Implementation

The Software Defined Network(SDN)decouples the control plane from the data plane.The control plane is responsible for logical control and maintenance of the global network view.The data plane is responsible for data forwarding.This approach simplifies network management and increases the openness and flexibility of the network.During the deployment of the SDN network to the WAN,the location of the controller directly affects the network delay and affects the overall performance of the network.In this paper,the SDN controller placement problem of wide area network is proposed to shorten the network delay.The SDN controller placement algorithm based on density peak clustering is proposed and the SDN controller placement system is designed and implemented.The main research contents and contributions of this paper are as follows:This paper studies the WAN controller placement optimization techniques for software-defined networks and summarizes the advantages and disadvantages of horizontal distributed and vertical hierarchical architectures.The problem of controller placement in horizontal distributed architecture is described and analyzed.This paper proposes an SDN controller placement algorithm based on density peak clustering.Firstly,density peak clustering is carried out on switch nodes with no less than average degree to obtain the initial clustering center point.Each switch takes the closest clustering center point as the center point of this point.In each subnetwork,the point with the largest compact centrality is taken as the clustering center of this iteration,and the shortest distance from switch node to the clustering center is recalculated until the distribution of clustering center and switch node is unchanged.The final cluster center is used as the placement position of the controller.Experiments on software-defined network topology show that the algorithm can effectively reduce network delay.Based on the SDN controller placement algorithm of density peak clustering,a software-defined network controller placement system is designed and implemented.It includes five modules:user management,topology construction,topology management,topology placement,and result display.The function of the system was verified by experimental tests.