Research And Implementation Of Parallel TCP In Acceleration System For WAN Application

Current internet has a challenge to its response time with the development of applications. To solve this problem, increase bandwidth may be a solution, but it couldn't get good effect as the delay's influence. WAN acceleration technology has been suggested to address this problem in current network hierarchy in recent years.Firstly, this thesis categorizes and introduces the main WAN acceleration technology. Our lab has implemented an application-layer protocol based WAN acceleration system, however, this solution based on especial protocols which have too much handshake on application-layer. Parallel TCP has better generality in application acceleration.In the following, parallel TCP technology is discussed and two kinds of adaptive increase TCP algorithms are presented, including buffer increase ratio-based algorithm and congestion-based algorithm. Besides these, an adaptive schedule algorithm based on the shortest queue first policy is presented to solve the parallel flows' schedule. Base on these algorithms, we analyze the requirement and summarize the target of the system to proposal a solution for Parallel TCP transmission system. With the basic functions, we partition the whole system to many modules and accomplish them step by step. The implementation refers to many important technologies, such as the design of communication protocol, control of parallelism, synchronization of multithreading and so on. Then, some tests and analysis result of the parallel TCP and the presented algorithms are given using test bed. Comparing with the current application-layer gateway acceleration, parallel TCP technology is more general in application, not only adapt to big block data transmission (eg.File transmission), but also small packet(eg.Web applications).Finally, the thesis summarizes the current existing open issues, and provides some further directions.