Research On Congestion Control Based On Packet Marking

With the rapid development of the Internet, the number of consumers is rapidly expanding and the structure of network is becoming more and more complicated. thus, a serious problem of this kind of burst growth results in network congestion. Now, the congestion control mechanism has already become an important topic to assure the QoS of network.We analyzed the basic principle of the current congestion control mechanism. To mainly aim at the shortage of the exsting active queue management, we pay attention to the improvement in the composing of round-trip time, slow-start,sliding-cwnd, the arrival rate of transaction stream and the packet marking,which minishes the error of the RTT and the accuracy of the packet arrival rate.In this paper,we investigates REM algorithm. A new improved AQM is presented. At the same time, the congestion information feedback and the congestion window adjusting strategies are further given. Finally, NS2 simulation results demonstrate that the new strategy can significantly reduce both packet losses rate and also contributes to the management performance of the router buffer. It also provides a better granularity control over the congestion window.It must be pointed out that with the burst of multimedia into the network the TCP stream fairness is influnced at the respect of the resource share. This paper analyzed some factors about fairness. An improved packet marking strategy based on Diffserv and packet arrival rate is also presented.It can give a better rate estimation and a better packet marking algorithm. We make the new congestion control mechanism together with AQM working in the core router. The result of the comparative simulation shows that the new mechanism is friendly with TCP.At the same time, it contributes to improving a system throughput.