Data transmission method and apparatus

Abstract

The invention discloses a method and apparatus for transmitting data, belonging to the communication technical field, the method comprises: acquiring time values of information waiting for affirmation of each file block information in present scanning time sliding window; when the proportionality of file block for no receiving affirmation information is small or the file block information with time values of information waiting for affirmation larger than the over time value exist, removing the transmitted file block information from the window, loading the un-transmitted file block and immediately transmitting, if the file block information with time values of information waiting for affirmation larger than the over time value exist, also adjusting the width of the sliding window, retransmitting the file block corresponding to the file block information. According to centralizing the file blocks with possible overtime waiting for affirmation information in the window, the dependence on each file block in the window can be reduced, the condition of transmitting the file block of the whole window can be prevented when the new file blocks are not read and the small quantity overtimepackages are waited, the file transmitting efficiency is greatly improved, the file block transmitting speed is improved, and the occupied network resource can be saved.

Description

technical field [0001] The invention relates to the technical field of communication, in particular to a data transmission method and device. Background technique [0002] With the development of network technology, the network instant messaging tool (IM, Instant Messager) has been accepted by most users today and has become an indispensable software tool for users, not only in the usual leisure and entertainment, but also in the user widely used in work. Therefore, users put forward higher requirements on the ease of use, stability, security and other aspects of IM software. Among them, file transfer, as a function supported by the network instant messaging tool, plays an important role in the basic IM service. How to transfer faster and more efficiently is a problem that requires long-term research. [0003] At present, the method of realizing file transfer is based on the UDP (User Datagram Protocol, User Datagram Protocol) sliding window mechanism: the sender divides t...

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Problems solved by technology

[0005] In the process of realizing the present invention, the inventor found that the above-mentioned prior art has at least the following shortcomings and deficiencies: on the one hand, as long as the waiting time of the file block exceeds the RTO, the sender thinks that the file block has failed to be sent, and the file block needs to be rewritten. However, if the waiting time of the file block exceeds the RTO, it may be due to the loss of the confirmation packet fed back by the receiver, that is, the receiver has actually received a file block, but due to the loss of the feedback confirmation information, the sender mistakenly believes that the file The block transmission failed, resulting in the resend of the file block, affecting the transmission progress and wasting network transmission resources;

[0006] On the other hand, when retransmitting file blocks, it is necessary to reduce the width of the sliding window first, clear the sliding window, and then send the file blocks that have not been successfully sent. Due to the need to clear the sliding window, the retransmission efficiency is low; Reduce the width of the sliding window, especially when the network is unstable, the probability of resending file blocks increases, so the probability of needing to adjust the width of the sliding window increases, resulting in continuous and violent fluctuations in the width of the window, which in turn causes unfavorable necessary timeout

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