Research And Application Of Load Balancing Algorithm Written By Software Defined Network

Internet appeared in the 1970 s,which has become an indispensable part of human production and life.With the explosive growth of network scale in recent years,especially the rapid development of real-time services such as online video,live broadcast and news release in streaming media business,the service quality assurance of "doing the best" in the traditional network architecture is more and more unable to meet the realistic demand.Therefore,in order to solve this problem,people put forward many models to improve service quality on the basis of traditional IP network architecture,but they cannot achieve obvious optimization result because of some network hardware limitation and related complexity.So the software defined network(SDN),a new type of network architecture,is proposed.Its core idea is to decouple the network from the tight coupling of traditional devices to the control plane and the forwarding plane.Since traditional network traffic forwarding only calculates a single shortest path,and ignores congestion and resource consumption caused by heavy link load.To solve this problem this paper proposes a QoS guarantee model for streaming media service based on link load and uses the advantages of SDN centralized control network to divide the traffic in the network into ordinary data stream and video stream.In this thesis,the bandwidth reservation of video stream is guaranteed as 30mbit/s,and two kinds of experiments are carried out to compare the limited bandwidth resources.The three factors of delay,packet loss,and jitter in the link in real time of the controller monitors,and then uses the KSP algorithm to select the K shortest paths,and then uses the weights of the three factors of the K path to evaluate the best path.The calculated routing results are sent to the switch to complete the rapid data transmission.The dijkstra algorithm is used for routing design for ordinary data flows.The principle of shortest path priority is used for data traffic transmission.By building simulation platform and simulating experiment,the real-time video stream can be selected reasonably in the link of load pressure,which makes the video stream play properly,which proves that the scheme has the effect of link load balance in real-time video transmission.