Research On Congestion Control Protocol For High-Speed Network

The Internet congestion control mechanism always is one of active topic of the network research community. Transmission congestion control does an effective job to matching traffic demand to available capacity of network. Results of congestion control research play an important role in the quick development and steady functioning of applications of the internet. With the breakthrough of communication technologies, the Internet is shifting to the age of high-speed network, which is called as High Bandwidth-Delay product (BDP) network in the network research community. However, the very reason of TCP's congestion control mechanism AIMD makes problems for current standard TCP facing the high BDP network. Research on congestion control protocol for the high speed network has new challenges, it also is the main topic of this dissertation. The content of this dissertation comprises two parts: the unicast transmission congestion control protocol and the reliable multicast congestion control protocol for high speed network.Firstly, the results of simulation experiments show that Variable-structure congestion Control Protocol (VCP) has the problems of convergence and fairness. In order to solve these two problems, we proposed the Extended Variable-structure congestion Control Protocol (EVCP), which was based on VCP. EVCP adopts convergence controller to speed up traffics converging onto fair share of bandwidth. We also mathematically analysed the reason of improvement of convergence and fairness. Then, we carried out simulation experiments to show the performance of EVCP.Secondly, we proposed the EVCP's enhanced version. It multiplexs four bits of Class of Traffic segment in Ipv6 header to improve granularity of congestion feedback. Based on real-time congestion feedback information, EVCP's enhanced version can dynamically control congestion window. EVCP's enhanced version increase the congestion transition point and decrease the AI range of load factor. These measurements help EVCP's enhanced version to improve the performance of convergence and fairness. Simulation results show that EVCP's enhanced version notonly keeps the advantages (high utilization of link, low persistent queue length and small packet drop rate) of VCP but also improve the performance of convergence and fairness.Last, in order to meet the development of the Internet especially the deployment of high-speed network and the requirement of high speed reliable multicast, the reliable multicast congestion control protocol not only keep fairness but also should make contribution to improve the utilization of link. We proposed a XCP framework based reliable multicast congestion control protocol (XRMCCP). XRMCCP extends the XCP to support one-to-many reliable multicast congestion control. XRMCCP is a window-based single rate reliable multicast. Simulation results show that XRMCCP can achieve the fairness between XCP traffics and XRMCCP sessions and among XRMCCP sessions. Additional, XRMCCP only need very short time to converge onto fairness share of bandwidth and improve the utilization of link. XRMCCP suits the reliable multicast in high BDP network environment.The main contributions are as follows: EVCP and EVCP's enhanced version are proposed to improve the performance of convergence time and fairness. EVCP adopts the convergence controller. EVCP's enhanced version adopts both the convergence controller and the methold of dynamical congestion window control. Additional, in the research topic of reliable multicast congestion control protocol for high-speed network, we proposed a XCP framework based Reliable Multicast Congestion Control Protocol (XRMCCP).