Fair Bandwidth Allocation Algorithm For The Simulation Study

With the development of the Internet,the users and the applications of it are increasing rapidly.Because different applications and users share the network bandwidth,when the network can't meet the user's need,it will cause the competition.So the fairness of bandwidth allocation is becoming more and more important.People make many researches on the mechanism of bandwidth allocation,but except fairness they weakened many other network performances,such as throughput,Round-trip delay.People make many researches on the mechanism of bandwidth allocation,and this paper has made further research on the mechanism of bandwidth allocation based on the earlier research,and proposed a new algorithm.This paper first introduces the reason of unfairness in bandwidth allocation and points out the necessity to study on bandwidth allocation.After that,this paper states on relative knowledge including bandwidth sharing model,impact on the performance of network by vicious flow,the standard of fairness evaluation as well as main fair bandwidth allocation algorism(End-to-end congestion control algorithms and router-based queue management algorithms and queue scheduling algorithms),etc.The third chapter introduces some typical fair bandwidth algorithms and gives an outline of the structure,steps to execute and a new protocols and the generation of TRACE of NS2.The innovative point of the study is that:1.Several typical algorisms of fair bandwidth allocation are simulated by NS2.And can obtain advantages and disadvantages of previous algorithm on different performance parameters by a comparative analysis of simulation results.2.Detailed analysis of the advantages and disadvantages of Core Stateless Fair Queue Management algorithm is made in this paper.Much improvement is to be made in this algorithm. In order to increase the utility ratio and throughout capacity of the high bottleneck link,this paper proposes an improved GCSFQ Algorism which combines the algorithm for RED and SRED cache strategy and uses a mechanism of CHOKE algorithm to control the UDP flow, which displays the fairness and improves the throughout capacity of the link.3.The simulation model built by network system in NS2 shows that the modified GCSFQ improves the fairness and the utility ratio.Also,its time delay characteristic can provide references for multi-service QoS.