VoIP Traffic Identification And Control Based On DPI Technology

VoIP (Voice over Internet Protocol) is a new rise of Internet communication technology.Because VoIP has the characteristics of low cost and flexible, which generates a huge threat to thetraditional telecom operators, especially for domestic and international long distance callservice,and makes the operators lose a great benefits. Since VoIP can bring a lot of profits and therelaxation of national regulatory, many illegal operators began operating VoIP services, resultingin reduced profits of traditional telecom operators; national regulatory for PC To Phone service isstill in a state which does not start, when unexpected situations occurs,the country can not ensurethe security of communication systems; many virtual operators have already conducted business inthe domestic, however, the state has not yet begun to regulate them, there is no relevantmanagement experience. Therefore, the country needs to research related technology to deal withtheVoIP’s threatforthetraditionaltelecomoperators.We need to accurately identify the VoIP traffic in the network, and then the VoIP traffic canbe managed. This paper focuses on the key technology of VoIP network traffic detection, deeplyanalyse a various of network traffic identification technology, the AC algorithm is analyzed, andon this basis, design and implement a network traffic monitoring system, which can achievedetection and control for the VoIP network flow.The main contents of this paper includes thefollowingsections:(1) This paper researched on the key technology—DPI network traffic identification(deeppacket inspection technology) and DFI (depth/dynamic flow detection technology), compared theadvantages and disadvantages of these two kinds of traffic detection technology, and combinedand rationally used two kinds of technology to achieve the identification of network traffic. Thenalso studied the control technology of network traffic, network traffic control technology werecomparedandanalyzed.(2) The theoretical basis for DPI technology—pattern matching algorithm was researched,wefocused on AC automata algorithm,and then analyzed the application of AC automata in DPIdetection.(3) After researched and analysed of the key technologies of network traffic identification andcontrol,we presented a solution of network traffic identification and control technology based onDPI, designed and implemented a network traffic identification and control system, and thenthe realization of traffic identification module, the working principle of recognition engine anddetection methods of packet were analyzed in detail, and introduced the DPI feature library, the network deployment scheme of the system is finally introduced in detail, and proposedan improvednetworkdeployment.(4) The network traffic monitoring system requires regularly to upgrade feature library usedto deal with the rapid development of network technology. After testing, the rate of the systemidentifies the network traffic is high, which can identify more than one hundred kinds of VoIPnetwork application software, testing for blocking VoIP traffic is also very successful, the systemhasgood performanceonthestabilityandavailability.