Design And Implementation Of A Linux-Based P2P Traffic Control System

The P2P applications used to play a role in development of Internet, while with P2P application's rapidly developing, it takes more and more network bandwidth, and P2P application begins to influence traditional Internet business like WWW, E-MAIL and FTP. How to meet the impact of P2P becomes a problem that ISP has to face. Traffic control is the point to solve the problm.The traditional packet filtering firewall is working in Layer 2,3 or 4 of OSI model, which uses MAC, IP and port of TCP/UDP. In recent years appears DPI, traffic feature identification and so on, in which DPI is adopted widest. As to the problems of P2P traffic control, this paper presents a P2P traffic control model of DPI and other methods, on the basis of research of P2P traffic identifying and traffic control. The paper programs and implements the system by analyzing the way Netfilter works in Linux2.4 kernel.The research work and contribution can be summarized in the following aspacts:(1) Introducing the basic concept and development of P2P.(2) Analysing the theory of P2P traffic control technology from the aspect of P2P traffic identifying technology and P2P traffic control technology.(3) Introducing how Netfilter works in Linux kernel and introducing IPTables, which can administer Netfilter in user space, and structure of connect trace. The paper analyses function of Netfilter kernel interfaces and theory of communication between user space and kernel space from the aspect of source code.(4) Designing and implementing a Linux-based P2P traffic control system. The paper first ayalyses function of each module of system, then descripes design principle, and lists the key function interfaces and data-struct of each module. In final, the system passes the test, which demonostrates the feasibility and practicability of the system.