Research On Congestion Control Algorithm Based On Multipath TCP

With the development of modern Internet technology,there are more and more applications that integrate the daily needs of users,and the amount of business data has shown explosive growth.At the same time,the rapid development of mobile Internet smart terminals has rapidly improved the user experience,and also made the applications carried by the terminals more and more diversified.In today’s era,these mobile terminals have multiple network interfaces such as Wi Fi and 4G/5G cellular networks,and Internet providers’ big data analysis and cloud computing data centers all require high-throughput transmission bandwidth,which prompts the current and multipath transmission is adopted in the future network architecture.Multipath Transmission Control Protocol(MPTCP)enables multiple interfaces to communicate through one connection for faster Internet access.In MPTCP,an end host transmits data simultaneously over multiple substreams on a connection.MPTCP can make full use of bandwidth resources,improve transmission efficiency,and provide friendliness for other traditional TCP protocol connections.At the same time,due to the use of multiple paths to transmit data streams,it also has a certain degree of flexibility.The congestion control algorithm in the multi-path transmission control protocol is the basis for controlling data passing through multiple sub-flows at the same time.The congestion control algorithm controls the data flow by achieving the goals of traditional TCP friendliness and congestion balance.The congestion control mechanism will be used in multi-path transmission.important role in the agreement.However,due to the different network characteristics of different network usage environments,when MPTCP is applied to various complex environments,it will cause the problem that MPTCP does not adapt to the scene.The transmission bandwidth that modern network infrastructure can carry is getting higher and higher,but some existing multipath congestion control algorithms are limited by the conditions at that time and cannot meet the current needs and status quo.Therefore,it is necessary to optimize the algorithm to adapt to the network environment of the application site,improve the overall transmission bandwidth,and fully demonstrate the advantages and characteristics of multi-path transmission.This paper analyzes the characteristics of MPTCP in detail,and optimizes the congestion control algorithm of MPTCP for network usage scenarios.The main work is given as follows:Firstly,according to the characteristics of high-bandwidth delay product networks,the method of evaluating link bandwidth is used,combined with the idea of coupling to ensure friendliness to traditional TCP,and optimize the congestion control algorithm.According to the design principle of multipath congestion control algorithm,in order to improve the flexibility of MPTCP to adapt to high-bandwidth delay product network,a new network congestion control algorithm,EB-LIA,is proposed.In this paper,simulations are carried out in different experimental topology environments,and are compared with other congestion control algorithms.The experimental results show that the proposed scheme can improve the network transmission performance of MPTCP in this network environment,and maintain a good performance for traditional TCP friendliness.Secondly,this paper proposes a transmission optimization algorithm for multipath congestion control based on packet loss discrimination.Many congestion control algorithms do not distinguish between packet loss types,and use the method of halving the window in the congestion avoidance stage.Then,it prevents the sending window from being kept stable at the high sending rate stage,which may easily cause the sub-flow sending data flow to be unstable,and the window recovery time long,resulting in reduced throughput.Aiming at the congestion control algorithm in the network environment sensitive to packet loss,a multi-path congestion control optimization algorithm based on packet loss discrimination,DL-LIA,is proposed,and different sending window adjustment methods are adopted according to the differentiated network packet loss types,so that the window can return to the high state faster and increase the sending rate.Finally,the performance of the proposed scheme is verified through some simulations,and the experimental results show that the performance of the designed algorithm is better than the original algorithm.