Research And Implementation Of IP Network Congestion Control Technology Based On Local Optimization Strategy

Network has provided an ideal platform for information exchanging and sharing for the public and plays an irreplaceable role in the informational society. In recent years, the users and information in the network expands greatly. However, the increment speed of network resource and the upgrading speed of network facilities are far behind, which leads to a series of problems. The most urgent one is the network congestion caused by heavy network traffic, which leads to network collapse and greatly affects the network performance.There are mainly two reasons that lead to network congestion. One is network resource shortage which caused by the rapid growth of the network information. Simply adding bandwidth to the Internet backbones can not solve the problem fundamentally. The other one lies in the topology-driven nature of routing protocols, which cause some links on the shorter path overloaded while other links on the longer path is lightly loaded or idle. In this thesis we study the congestion control technologies and propose an IP network congestion control technology based on local optimization strategy. The technology is used to solve congestion occurred in the network. Once the congestion is detected, an area near the congested link would be found under some specific criteria. To eliminate the congestion, several traffic balance measures will be carried out in the area, including making good use of idle or lightly loaded links, sending the congested traffic out from not only the congested link but also other links. The technology is used together with OpenFlow, and is implemented on the IP network congestion control system. Experiments are made to prove the performance of the congestion control system. The main contents of this thesis are as follows:(1) Current network congestion control technologies are studied in depth.(2) A congestion control mechanism used to solve congestion is proposed. The concept of local optimization is introdued into this mechanism.(3) The research results mentioned above is realized on the system platform and OpenFlow technology is introduced to control the data packet forwarding.(4Experiments are made to prove the function and performance of our technology.