Research And Implementation Of Network Traffic Inspection And Control System Based On DPI

With the rapid development of Internet technology,endless variety of Internet applications are produced from simple traditional applications such as Web browsing,simple email,FTP,Telnet and so on in the past,into today's diversified network applications such as instant massage,online video,network games.But it also brings about some disadvantages such as the rapid growth of network bandwidth and the lack of network bandwidth resources.Especially instant communication software not only has the function of text chat,but also has the function of VoIP.This is a new trend and it brings a bad impact on the existing network service and quality which are provided by the internet providers.It is a worthwhile topic that how to remain the network providers' core status in the tradi-tional communication network with the development of new technology.Network management departments want to know the user's traffic infor-mation and situation which carries effective data,discove equipment fail-ure in time,prevent the link congestion,prevent the invasion of network virus,and give a guarantee for national security and business regulation by network traffic monitoring systems.These need to identify various network traffic effectively and control them effectively.Aiming at above problems,this paper mainly researched in network traffic inspection and control technology.On the base of analysis of the existing network traffic detection technology and control technology,this paper proposed a network traffic inspection and control system based on Deep Packet Inspection technology(Deep Packet Inspection,DPI).Compared with the existing network traffic processing systems,this sys-tem used a linkage control engine with straight road control technology and bypass jamming technology.It could provide different processing approaches according to different types of traffic.This could improve the stability and the processing efficiency of the system.This paper designed specific traffic inspection and control ways for the specific applica-tions,and gave the test results in the end.The main work of this paper can be summarized as follows:1.After analysis and research on the types of network protocol,this paper proposed an organizational architecture based on tree structure for the characteristic library.It can improve the matching speed of the char-acteristics library in some extent.2.For the charateristic library would increase endlessly with the growth number of identifiable applications.This paper put forward a dy-namic updating mechanism for the characteristic library,using the web crawler technology to implement it,and gave the specific implementation process.3.Through analysis on network traffic control technology,this paper designed a linkage control engine,which could take different processing approaches to different applications' traffic.This not only increase the re-liability of the system,but also increase the processing performance of the system,and can reduce indirectly the network traffic which needs to be controlled at the same time.4.This paper designed an organizational architecture for the network traffic inspection and control system based on DPI,and described the im-plementation process deeply about network packet capture module,char-acteristic library module,traffic inspection module,policy configuration module,linkage control engine and database module.5.The network traffic inspection and control system based on DPI was tested.On one hand,The function of the system was tested from the aspects of the recognition rate and the control effect.On the other hand,the performance of the system was analysed from the aspects of the throughput,the number of supported protocols and the robustness.