The Research On Routing Selection And Adjustment Strategy In OpenFlow

The rapid development(e.g.mobile,cloud,and big data)in information and communication technologies are new challenges to future Internet,for which accessibility,high bandwidth,and dynamic management.However,compared with the traditional network,Software-defined networking(SDN)can realize easily the need of future Internet.SDN is characterized by its three distinguished features,including decoupling the control plane from the data plane,logically centralized control network and programmability.These features provide efficiently configuration,better performance,and greater flexibility.In SDN,the routing of network flows still is the key issue.The features of SDN allow we to program our own routing strategies according to our need and global network resource state in the controller.The controller selects the path for a flow according to the routing policy and then sends corresponding routing rules to switches.Due to the limited network resources(switches rules number resources,links bandwidth resources),inappropriate routing choice may lead to many problems,such as network congestion and low resources utilization,so the routing selection problem has the great research significance.To solve the routing selection problem in SDN,two routing algorithms are proposed for two different scenarios respectively,and its main idea is to improve network efficiency by distributing or adjusting the path of flows.In a network,the number of flows with low rate is small which mainly produces the load on the link traffic in the network.The number of flows with low rate is large which mainly produces the load on the switch rule capacity.Based on this network characteristic,the main work of this paper as follows:(1)Proposing the routing algorithm based on flows classification,and its used in the initial path selection for the flow.This algorithm classifies flows according to its rate,and adopts different routing algorithms for different classes.Compared with the existing research experiment in the same network environment,it shows that the proposed routing strategy can balance the network links load,reduce the network rules number,and significantly improve the flows arrival rate.(2)Proposing the routing adjustment algorithm based load-balanced,and its used when network is congested.The algorithm takes advantage of the global flow control characteristics of SDN,and get a flow and its route with the lowest reroute cost by combining with the attribute of the flow,network topology and traffic distribution,and then rerouting to realize network load balancing.Experimental results show that this algorithm can balance the load of network links and improve network utilization.