Research On The Deployment Scheme Of Elastic SDN Network With Static And Dynamic Combination

Software defined network(SDN)is a new network architecture,which separates the device control with the data forwarding,thus realizing the flexible control to the network through the controller.Therefore,the placement of the controller is critical to the overall performance of the network.Because the traffic in the network is dynamic,the static deployment relationship of the controller may cause the load imbalance between controllers.Through the analysis of the existing research scheme,this paper proposes a controller placement scheme with static and dynamic combination..First,this paper proposes a static placement scheme for controllers.In order to meet the dynamic changes of the traffic in the network,we dynamically migrate the switch based on the static deployment scheme to achieve dynamic flow of load between the controllers,thus achieving load balancing among the controllers.The specific research content of this paper is as follows:1.Static deployment scheme of controller based on IBPSO.In static deployment scheme,we use the load of the controller as an optimization variable to establish a mathematical model that is optimized for the load of the controller.The improved binary particle swarm optimization algorithm is used to solve the mathematical model to obtain the deployment plan of the controller.In this scheme,the controller deployment problem is modeled as particle location optimization in particle swarm.Then the processing capability of the controller is considered as a constraint,and the load balancing function of the controller is used as a fitness function to evaluate the deployment scheme.Each particle is optimized by iteration to the best position and global optimum position,and an approximately optimal SDN controller deployment scheme is finally obtained.2.Dynamic migration scheme of switch based on load balancing.In order to meet the dynamic characteristics of traffic flow in the network,this paper implements load balancing between controllers through dynamic migration of switches.In this paper,the load imbalance detection algorithm is used to detect the control load difference in the network.Once the element value in the load difference matrix is greater than the threshold,the switch migration mechanism is triggered.We use the switch migration algorithm to select the emigration controller,and the pending switch and the immigration controller are in the switch.The experiment shows that the switch migration scheme of this paper can effectively reduce the migration cost on the basis ofrealizing controller load balancing.