FAST TCP Congestion Control Optimization Based On Linux

Modern network and its applications have made remarkable development,making the link carrying more and more data.The speed of transmission of data in the network also requires more rapid.Modern network transmission cannot meet more data,faster transmission requirements.In the future,large data,cloud computing,virtual reality and augmented reality applications,as well as wide-area interconnection,the establishment of the goal of connecting the world together,calling for new technology allows the network to transmit more data,and transfer data fester.Now the bandwidth of network,especially the WAN link is still relatively small and the delay and packet loss rate are large.The traditional classical TCP transmission algorithm has been unable to meet the needs of modern and future large bandwidth long delay network.The new transmission protocol and Various optimization algorithms are continually being proposed,but because of the more or less shortcomings,cannot be widely used.Therefore,this paper chooses the latest TCP congestion control algorithm,FAST TCP[1],to explore its transmission effect in the current wide area network environment,study its shortcomings,and improve the existing problems.Firstly,this paper introduces the current optimization technology and method of WAN,and studies the relationship between TCP congestion control mechanism,TCP throughput and link bandwidth,delay and packet loss rate.Secondly,by setting up network link and analog link bandwidth Time delay and so on.Based on the Linux platform,the FAST TCP congestion control algorithm is studied,and the problem of the fluctuation of the congestion window and the fairness of the RTT are analyzed.An improved method of smoothing the window fluctuation is proposed and the congestion is provided through the Linux kernel Control hook,to achieve the improved congestion control program.Finally,by comparing the FAST TCP algorithm optimization before and after the test to verify the effectiveness of optimization.The main work and innovation of this paper are as follows:Based on Linux TC tool to simulate the WAN bandwidth,delay,packet loss and other parameters to build links;Based on the Linux platform to create a dynamic kernel module to achieve FAST TCP congestion control algorithm;The improved FAST TCP congestion control algorithm is proposed and implemented,and then the transmission effect between the algorithm and the CUBIC algorithm is widely used.