Research And Design On DPI-Based Network Traffic Identification And Control System

In recent years, with the rapid development of Internet technology, People’s online behavior has changed from the simple text chat, file transfer, e-mail in the past to today’s diversified way, for example, VoIP, online video, multimedia conferencing, etc. Meanwhile, network traffic is growing rapidly and Bandwidth resources are increasingly strained, in particular P2P applications take up a lot of network bandwidth, affecting the user’s Internet experience, and a large number of illegal VoIP applica-tions occupy telecom operator’s network resources for profit, it impact on traditional voice telephony services, In addition, operators also to carry out a number of value-added services by analyzing and mining users’ online behavior and habits, when faced with these challenges and market demands, Operators will achieve the goal that realizing and controlling network traffic,and it is a very important work.In this paper, author designed an effective DPI (deep packet inspec-tion technology)-based traffic identification and control system after reading the related references and researching the related technolo-gy. According to the characteristics of the protocol layer’s string, and combining with the advantages of AC (Aho-Corasick) algorithm and the algorithm of regular expressions, the system optimizes the traditional string matching engine and introduces the DFI(Deep Flow Inspection) mechanism. According to the transmission features of P2P(Peer to Peer) and VoIP(Voice over Internet Protocol) protocol, and taking an example of three typical applications,the author designed the identify and control program and gaven the test results in paper.The main work of this paper include the following aspects:1. Combined with the advantages of AC (Aho-Corasick) algorithm and the algorithm of regular expressions, the paper designed an AC-RE engine based on DPI, and the system introduced DFI (Deep Flow In-spection technology) recognition mechanism and implemented the func-tions which can identify the encryption protocol.2.Accroding to researching the technology of P2P、VoIP and P2P-VoIP,the paper designed three identify and control programs for three typical protocol in BT, YahooMesenger, Skype for instance, and gave the knowledge description sample.3.The paper designed the overall architecture of a traffic identifica-tion and control systems based on Linux and completed a network struc-ture deploy in which the system series in network.4. After completing the design of system,the paper tested the four common software for the functiona of identification and control and test results show that the hitratio is more than ninety percent and the success-rate is hundred percent.