Research And Design A System About P2P Protocol Identification Based On Explicit Features

Inside the Internet field,P2P(peer to peer)model is contrary to C/S(client/server) model.With the distribution and organization of unique characteristics,P2P make rapid development of the Internet and has become part of the Internet can not be ignored. The application of P2P has been extended to the business, government, telecommunications and other major areas.The statistics show that the P2P traffic has occupied 60% - 80% of the total flow on Internet. The rapid growth of P2P traffic has led to the unreasonable allocation of network bandwidth and huge consumption, has become the largest consumer about network bandwidth. Therefore, accurate identification of P2P traffic is important to guarantee QoS, traffic monitoring, accounting management.This paper studies the development and current status about identification technology of network protocol.On the contrast about a few identification technology,it is concluded that port-based and ip_based traffic identification method has been very limited.Based on application layer explicit features is the more mature technology, widely used in various network device identification system,and could identify P2P traffic accurately.The dominant factors of this mechod is the algorithm of string matching. This paper analyzes the implementation and principle of the existing string matching algorithms, and then propose a new algorithm which could improve the efficiency.Because of the flexibility and efficiency of Linux kernel network stack in deal with data packet,this paper set up a system to identify P2P protocol on the basis of Netfilter/iptables framework,using the new string matching algorithm.The test shows that this method has good recognition results.