A Research Of Router Queueing Algorithm For Multi-service Bearer Network

The computer and communication technology are speeding continually, which givebirth to the diversification growth of the end-user applications, multi-type businessapplications and IP access network are advanced, the enlargement in the network sizeand diversification of network applications have prompted network facilities from thetraditional basis of information evolved into a social infrastructure. At the same time,the defects in openness of the network itself and the complexity of its design as well asthe heterogeneity of today’s network architecture, the network itself and multipleapplications on it face kinds of challenges, of which feasible and effective congestioncontrol mechanism is urgent to solve. Efficient congestion control deployed inmulti-service bearer network is the key to improve network performance, improvemulti-user-oriented quality of service (QOS), optimize network design.As a cooperative way of the end-to-end TCP congestion algorithm, therouter-based queue mechanism has been the focus in recent years. It implements fromtwo sides: the queue scheduling and queue management, the research of this thesis isbased on active queue management(AQM), we have analyzed existing species AQMalgorithms, mostly focusing on classical RED algorithm principle as well as theperformance analysis, after which based on the RED, from the aspects of sensitivityparameter settings, queue length stability, fairness of resource consumption, we makeanalysis and performance contrast between improved algorithm ARED, BLUE, FREDand RED, then based on the relationship of queue length and packet loss rate, makesome improvements: propose improved algorithm m-RED, with experimentalsimulation platform NS2, deploy the multi-service bearer network environment, verifythe performance of the improved algorithm in stability of average queue length, QOS(link throughput, delay, jitter, packet loss rate, etc).The main contents in this paper are as follows:1, Summarize up the research status in the region of congestion avoidance andcontrol at home and abroad, and discuss the necessity and feasibility of theimplementation of congestion control from the intermediate node router. Focus on the analysis of the AQM default candidate algorithm-RED principle, performanceadvantages and potential defects, and give a brief overview of the principles,performance on existing ARED, BLUE, FRED.2, Base on the theory of stochastic processes and mathematical models as well asexperimental simulation, derive the non-linear relationship between the average queuelength of the buffer and packet loss, with which could well solve the link low utilizationand forced packet loss, in low and high load respectively. With the above conclusion,propose nonlinear improvement of the segment on the RED packet loss function.3, Deploy the environment of multi-service bearer network on the experimentalsimulation platform NS2, analysis and verify the proposed algorithm performance instability of mean queue, deviation of delay, packet discarding proportion, throughputwith scene changing from two angles: the single business of TCP and TCP、UDP mixedmulti-service.