Research And Implementation Of Fast Transmission Of Large Files

With the continuous improvement of social informatization and the continuous development of information technology,the Internet has penetrated into all areas of society.File transfer is one of the most basic and important functions of the network.The efficiency of file transfer will directly affect the user's experience and work efficiency,especially when transmitting large files.With the arrival of the era of big data,we have higher and higher requirements for data file transmission.Although the current updates of network technology and hardware facilities have improved the transmission rate of data files to a certain extent,the user's experience of file transmission has not been improved accordingly.How to optimize and improve the efficiency of file transmission,especially large capacity files,has become a research hotspot.TCP(Transport Control Protocol)is a widely used transport layer protocol,which provides reliable transmission services for users.Therefore,TCP is also a common protocol for transferring files in the network.However,due to its congestion control mechanism,TCP has been unable to make full use of the current network bandwidth resources.In order to improve the efficiency of large file transmission,the TCP transmission protocol is deeply studied and improved.The work mainly includes the following aspects:(1)The slow start algorithm of TCP is improved to improve the transmission speed of large files.Slow-start algorithm is an important part of TCP congestion control algorithm.Its main function is to control the congestion window growth of TCP connections in the start-up phase,so as to detect the available bandwidth of the current network.However,the traditional slow-start algorithm has low performance in the current high-speed network,which can not make full use of the available bandwidth in the network,seriously affecting the file transmission rate in the network.Therefore,we improve a series of problems existing in the traditional slow-start algorithm,and deploy the improved algorithm in Linux system.Finally,we verify the improved algorithm in the simulation network and the actual network respectively.The experimental results show that the improved slow-start algorithm effectively improves the transmission efficiency of large files.(2)Using concurrent TCP stream technology to improve the transmission rate of large files.Parallel TCP stream technology improves data transmission rate by increasing the number of end-to-end TCP connections.It does not need to modify the TCP protocol stack.Its essence is a parallel data transmission technology in application layer.This paper provides a reasonable numberof concurrent TCP connections by adding network environment detection function,which greatly improves the transmission rate of large files.