Research And Design On Protocol Analysis Engine In Service Selection Gateway

With the rapid development of Internet, people are more and more focusing on how to provide individualized and incremental service. Under such circumstances Service Selection Gateway (SSG) emerges. Unfortunately most SSGs on the market are ISP oriented coarse-grained devices; where as no product is suitable for content provider. The Protocol Analysis Engine that is going to talk about in this paper is the core module of this very kind of device which is access controlled by URL.By researching on the requirement of SSG, this paper proposes the work procedure, design model and implementation strategy of Protocol Analysis Engine, and makes a deep study on the key techniques of this module. About the key techniques, this paper gives a method to resolve URL from HTTP segment by studying the HTTP protocol, and researches the TCP splicing technique which is used to realize the TCP connection control, including the problem of segment header modification. Besides, according to the characteristic of the URL routing look-up on SSG, an URL routing look-up method and the Refined Aggressive Hash Algorithm to improve the speed of routing look-up are given, along with a simulation test which testifies their efficiency.