Distinguishing Service Fair Bandwidth Allocation And Active Queue Management Studies

With the rapid development of Internet, various network business have put forward higher and higher requirement to QoS, People's interests and needs about the real-time application and multimedia application based on network is more and more urgent .And some problem ,such as how to develop deploy and change the current network to adapt this change and to meet people's various demands, has been urgent in the research field. The DiffServ model is put forward to solve this situation. The model also has some issues, such as the unfairness of the bandwidth deploy and the performance of queue management which is an important part of the classifier and conditioner of the router. This paper discussed the fair bandwidth deploy and the active queue management in the DiffServ network.The paper first introduces the two kinds of service models, the IntServ model and the DiffServ model; and discuss the unfairness of the bandwidth deploy in the DiffServ network and the marker which caused the unfairness of the bandwidth deploy. Then a new marker algorithm, which mark the packet dynamically based on the TSWTCM (Time Sliding Window Three Color Marker) is proposed. Simulation result shows that the algorithm improves the fair sharing of excess bandwidth.The paper describes several common AQM algorithms in detail. The paper discusses and analyses RED (Random Early Detection) algorithm, the representative algorithm of AQM, discusses two major shortcomings of RED: the instability disposition on parameter and the slow response to the network's load. Finally, the paper proposes an RED algorithm-DRED algorithm, based on the feedback theory in the Control field. The experiment results indicate the improved algorithm performs better than RED.