Abstract: This paper analysed the importance of P2P traffic identification. 13y summarizing literature, the existing method was divided into four kinds of traffic identification according to the mechanism of identification; port based classificanon, application-layer signatures, transport layer feature and machine learning. This study analysed in detail the principle of traffic identification and the critical problem and explored the recent research at home and abroad, measures to solve the problem and advantages and disadvantages. Following it, this paper made prospect for the future research trends.

Key words: Traffic identification,Machine learning,Decision tree,Support vector machine