Research On Network Traffic Control Technology Base On Linux

With the development of network technology,various applications emerge quickly,so huge amount of data transmitted overthe network, that their bandwidth requirements are very amazing, the rate of update could hardly catch up to the use. Without any kind of control measure, network congestion must be inevitable, thus the quality of the user's normal communication be affected badly. However, traffic control itself is a kind of intervention behavior to the Internet data flow, so an inefficienttraffic control behavior not only cannot reduce congestion, but will increase the network load, reduce the throughput, and deteriorate the environment of whole network. In view of above, a kernel module was designed to efficiently classify the data flows thenforward them with different strategies, on this way, high-priority users and applications can get adequate bandwidth.When classifying the data streams on the network, it must be always keep in mind that different user's requirement to bandwidth is not the same, and the time delay tolerance to different application is also inconsistent, thus during the traffic controlling, the distinguish between categories of users and application layer protocols is necessary, especially the P2P protocols traffic withtheir phagocytic properties should be distinguished and limited. Although there are many kinds of P2P protocols have different characteristics, normally the TCP and UDP are used alternately by them. The measure of feature values match is used to identify several commonly used P2P protocols, and then restrict them individually.The main work and innovations as follows:(1)A new net bridge was designed and loaded to Linux kernel to replace system's own one, byconfiguring the bridge, it could divide IP into different segments, which has different priority and allowed maximum flow parameter. On the analysis of the data flowing through the host, bridge recognize and identify P2P traffic, and then transmit them with different policies which based on the parameters set by user, in this way to reach a reasonable use of bandwidth.(2)In order to improve efficiency, to complete the processing of large amounts of data,HASH table was used to record the traffic, after the record is set, the package from the same traffic could determine the type of itself only by query HASH table, then the same control strategy could be used. On the other way, the strategy of transmitting package on the net deviceis rewritten, multiple queues were built on it, and each of them control transmit rate by the way of obtaining tokens.(3)When distinguishing P2P traffic, for the reason of more efficient, the measures based on port distinguish and DPI package payload investigation was used on the same time.