拥塞控制在宽带网络中是一个重要的话题。其主要目的是提高网络资源的利用率和提供给信源公平的资源分配份额。笔者讨论了宽带网络中基于反馈机制的各种拥塞控制策略和实现方法，指出了网络流量的高突发性和强相关性，以及不可预测的网络时延，应是控制算法设计中的难点，而提高网络利用率这一控制目的，又往往与性能分析中的公平性是冲突的，这就使得要得到一个最优的控制方法是困难的。最后，指出了对网络业务量特性的精确描述，以及在此基础之上设计控制算法，都要依赖于必要的数学工具。

Congestion control is an import issue in the broadband network, which aims at improving network utilization and fairness. Rate based closed loop feedback congestion control schemes and their various implementations in broadband networks are discussed. The high burstiness and strong correlations inherent in the network traffic are pointed out to be the key to the design of algorithm on congestion control, so is the delay time of the network. In addition, the goal for maximizing network utility often confilicts with the goal of fairness. All these show it is difficult to get a optimal scheme. Therefore, we denote that both the accurate description of the characteristics of the network traffic and the scubsequent design of the congestion control algorithm rely on necessary mathematical tools.

TB114.2

重庆市科技攻关项目 (99-745 )，重庆邮电学院青年教师研究基金