Designing Adn Implementation Of An SDN-based Flow Sensing And Bandwidth Control System

With the rapid development of applied Internet technologies, people are showing a greater dependency over Internet. Improved application services have driven people towards a better quality of online media, especially a higher demand for bandwidth. Therefore, how to make an effective use of bandwidth resource have become the most pressing problem.Traditional technologies to control traffic and bandwidth are very costly and hard to deploy, while the appearance of Software Defined Networking(SDN) has shed some new lights on this problem.The thesis conducts research on SDN-based flow sensing and bandwidth control system to find ways to make full use of Internet bandwidth. The thesis is composed of four major parts: first, a review of current research achievements of flow sensing and bandwidth control; second, the overall framework and explanations on some key issues; third, a detailed analysis of flow sensing and bandwidth control model based on multiple tables; and lastly, conclusion reached upon a large amount of tests on the performance metrics and functional metrics of the system. The key points are as follows:(1) A multiple tables based flow sensing algorithm is proposed. By using thealgorithm’s features of OpenFlow interchanger that can calculate the datapackage if it matches the principle of flowentry, the thesis follows thetechnology of multiple tables and adopts the testing method of combining bothative and passive flow sensing. It gets the utilization ratio of networkbandwidth by using a minor dissipation to sense the network traffic.(2) Designing and realizing the bandwidth sharing technology among multipleusers. As for network traffic control, the thesis believes that the bandwidth canbe shared by multiple users by setting a fictitious IP on all host computers as agateway, enabling the controller to choose the MAC of maximal WAN as theMAC replied by the gateway ARP and the host computer to send the datapackage to the Internet via this address. This will complete the dynamic routingprocess and realize bandwidth sharing.Detailed analyses and tests of our system are available in this thesis and the results proves that the flow sense sub-system with a minor dissipation can guarantee the quality of the test results with an accuracy rate reaches 96%. The results also shows that the sub-system of bandwidth control can assure the sharing of bandwidth and the load balancing at the WAN. In general, our system is proved competence in all tests and can meet the users’ needs for performance and functions.