Design And Implementation Of Congestion Control Protocol For The New Internet Transmission Control Protocol

At present,the TCP protocol is the most used transmission control protocol in the traditional Internet.However,with the growing demand for network users,single-path TCP transmission protocol has been exposed to the limitation of network development.At the same time,the development of access technology and the diversification of access methods makes multi-path parallel transmission technology possible.Beijing Jiaotong University relies on identification network research and designs a new Internet connection-oriented transmission control protocol(COTCP),which can support multi-path parallel transmission of data.This thesis analyzes and compares the existing multi-path congestion control algorithms,and studies the COTCP congestion control from the aspects of fairness,equalization congestion,and overall design.In terms of fairness,considering the traditional congestion control applied to COTCP,COTCP users cause N times path invasiveness to TCP users at the shared bottleneck link,which causes resource fairness problem.In this thesis,we propose a Dynamic Path Weighted Congestion Control(DWCC)algorithm based on the fairness problem.DWCC algorithm can dynamically change the weight factor of each sub-stream according to the difference of multipath transmission.It can ensure the fairness of TCP connection when a COTCP connection is sharing the link bottleneck,and realize the effective utilization of the network resources.In terms of balanced congestion,considering the COTCP multi-link equilibrium congestion will produce network instability,we propose a Link Data Evaluated Congestion Control(LECC)based on link data evaluation.The algorithm can accurately estimate the link state and adjust the congestion control window to improve the network stability.Finally,the whole module of COTCP congestion control is introduced,which provides a theoretical basis for the realization.Based on the design of COTCP congestion control.In this thesis,the congestion control algorithm has been achieved in the linux kernel.And the effectiveness of the COTCP congestion control algorithm is verified by experiments.Finally,the overall content of the COTCP congestion control is summarized.And put forward some meaningful research directions.