Research On Identification And Control Of The Instant Messaging Software Based On Characteristics Of Data Packets

Instant Messaging technology has gone deep into people’s work and life with the development of computer technique and network techniques. Mainstream Instant Messaging software is MSN software and QQ software in Chinese Mainland. comScore network company’s survey proved MSN possess 5.386 hundred million users recently; Tencent company’s official statistics manifests that the active users number of QQ software exceed 3.4 hundred million. Instant Messaging technology may on the one hand, take amusement and convenient communication to people, on the other hand, reduce the staffs’work efficiency while the staffs make free with the technology at enterprise and government agency, and also take problem to the network security.SMB(small and medium businesses)router is the necessary network equipment to connect Internet in above agencies. It can solve the problems above with adding the Instant Messaging filter firewall in the SMB router, and it also has practical activity.Linux has proved to be the best ERTOS(embedded real time operating system) with the advantage of open source, nice network performance and so on. With the research of Linux Netfilter and l7-filter, this paper discusses the design and the realization of the Instant Messaging software filter system based on the OSI layer7 in the SMB router. It includes:1. Discuss the current situation of the Instant Messaging software filter system of SMB router. Introduce the theory of Linux Netfilter, connection tracking, and l7-filter.2.Analyse QQ and MSN packets’application data using ethereal, and achieve a new protocol pattern through the research of all kinds of agency.3.Design the Instant Messaging software filter system based on OSI layer7, and raise a solution, as it was called semi-fast transmission, to the problem of the influence to router’s transmission efficiency by the Instant Messaging software filter system.4.Construct a testing environment to prove the Instant Messaging software filter system’s function. Test the semi-fast transmission’s transmit property, and the results manifest that the semi-fast transmission can lower the influence of the router’s transmission efficiency by the Instant Messaging software filter system by a wide margin.The Instant Messaging software filter system’s flow is clear, and its’code is high efficiency. The system’s web management interface is very convenient to use, and further more, it offer privilege user function, which permit the privilege user use the Instant Messaging software even when the system is powered on.