Research On Flow Optimization System Based On SDN

With the rapid development of the Internet and the popularization of cloud computing and big data,the current network traffic is increasing rapidly.Facing the rapid growth of traffic,many enterprises choose to expand the bandwidth of the leased line to guarantee the normal operation of the kinds of applications.For most enterprises,the average bandwidth utilization rate before expanding the leased line is very low,but in a certain period of time,a large number of traffic will result in network congestion.The expansion of the leased line really has an effect,but it will cause a lot of waste of bandwidth resource.Therefore,the enterprise urgently needs an intelligent way to dynamically dispatch these traffic to improve the overall bandwidth utilization and improve the user experience.The Software Defined Network(SDN)separates the network data plane and control plane,so that users can make a personalized,automated and intelligentized forwarding strategy to control the network.Although SDN has many advantages,it is a huge project to make a comprehensive transformation of the existing traditional network.Therefore,based on the original network architecture and drawing on the idea of SDN,this paper proposes a transitional SDN solution.At the same time,a flow optimization system is designed and implemented.Through this system,the network resources in the WAN can be safely,controllablely and flexibly scheduled.Based on the QOS demand of the whole application,the state of leased line and bandwidth information of the whole network,the system carries out the end to end path control and bandwidth allocation for the traffic with the goal of maximizing link value and load balancing.The control layer of the system is mainly divided into the flow monitoring module,the topology creation module,the configuration module,the flow analysis module and the algorithm execution module.the control layer interacts with the ODL controller and the underlying network device and interacts up with the MySQL database.The system flow monitoring module and topology creation module mainly provide the basic information on the network(real-time traffic information,topology information of the network layer and so on).The algorithm execution module is the core module of the system.The module refers to the algorithm used in Google B4 network(KSP algorithm,greedy algorithm,maximum and minimum fair value algorithm,etc.)At the same time,It makes some adaptations and optimization for the architecture of WAN and network devices.It will ultimately completes the reasonable scheduling of path and bandwidth.The configuration module uses the new protocol PCEP and Netconf to send the mass configurations of the path and the QOS rapidly.In order to verify the feasibility and validity of the system,this paper first tests the validity of the individual module and the correctness of the algorithm and then tests the whole system.This paper makes flow tests for different types of traffic to different enterprises under the current network architecture,The results show that the flow optimization system designed in this paper can well guarantee important application,and it can dispatch the traffic intelligently,automatically and fairly.It achieves the expected design goal.