Research And Improvement On Fairness Of Congestion Control Mechanism Of FASTTCP

With the development of computer and communication technology, people's demand for Internet has exceeded our expectations, the result is brought about the rapid expansion of network size and the increment of application fields. Therefore, more effective and reasonable control mechanisms for the smooth operation of existing networks play a vital role, in which the most basic and critical element is the congestion control, namely, how to effectively prevent or eliminate the congestion in the network availability. However, face to the multifarious environment of the network, congestion problems have not yet a perfect solution, The research about network congestion problem has also been a hot subject in both computer network and control theory.There are two primary components in end-to-end congestion control: one is the source algorithm executed by host computers or edge devices; the other is the link algorithm executed by network devices, such as routers or switches. There are many standards to measure the congestion control algorithm, and fairness is one of the most important one.FAST TCP is a new variant of TCP proposed by Netlab. We analysis the congestion control mechanism and fairness of FAST TCP.We analyzed on current FAST TCP model in detail, and tested its performance. We improved FAST TCP algorithm by adding a fair factor Through simulation, we analyzed and compared the throughput among TCP Reno,FAST TCP and F-FAST TCP. F-FAST TCP consistently outperforms other protocols in fairness. At last, we study the method of selecting factor.