基于区分服务的队列管理研究-无线电物理专业论文.docxVIP

Researches Researches of Queue Management in DiffServ Major： Radio Physics Name： Zhou Ting Snpervisior：Prof．Qin Jia一fin Abst raet DiffServ model is a principal solution of IP QoS，which implements relative QoS using priority policy．In DiffServ architecture，queue management is an important mechanism of congestion control，which drops packet to control queue size．Althoulgh DiffServ model and queue management have different goals，they get lots of connections．By extending actions to all kinds of traffic，differential services based on different priorities could be accomplished．Implement mechanisms to achieve AY PHB in DiffServ model constitute a significant research topic． In this paper,queue management in DiffServ model has been studied．The principles of congestion control mechanisms arc introduced firstly，and some of the current prevalent queue management algoritlmas discussed．After being analyzed the advantages and disadvantages，Two—Category Classifier(TCC)algorithm is improved in two ways．On one hand．a classier-discarder based on active learning method is constructed to approaching the problem of limited samples and static parameters．On the other hand，a subqueue management algorithm with differentiated performance is proposed for the purpose ofdifferent QoS requirements The simulation of the algorithm in the OPNET shows that the improved algorithm gives better packet loss ratio than the original one，and provides sarisfying differentiated performance．It presents a strengthen support to the anticipated results of the analysis Key Words：DiltScrv，Active Queue Management，QoS，classifier,linear discrimination 中山大学硕士学位论文第1章引言 中山大学硕士学位论文 第1章引言 1．1研究背景 在对IP QoS呼声越来越高的今天，区分服务(Differentiated Services，DiffServ 或DS)模型‘“21的思想已经被广泛应用到网络核心及边缘部分，并且被认为是解决 IP网络服务质量问题(QualityofService，QoS)的主要解决方案之一。但是，由于 Intemet上多媒体业务的不断增长，以及数据传输突发性的特点，网络容易出现拥 塞现象，其解决方法是采用拥塞控制，即在网络节点处采用丢弃策略，通过决定 哪些包被丢弃来分配缓存。I：ETF已经建议采用主动队列管理算法(Active Queue Management，AQM)t3】实现拥塞控制并保持较高的链路利用率。 区分服务与拥塞控制有着不同的研究目标，但是它们之间的关系密