一种支持多媒体通信QoS的拥塞控制机制

A Congestion Control Mechanism Supporting Multimedia Communications with QoS Requirements

本文针对Internet传输协议TCP的和式增加积式减少 (AIMD)拥塞控制机制不适应多媒体通信 ,而目前拥塞控制的研究又大多集中在尽量做好 (Best effort)服务上的问题 ,结合Internet上多媒体通信的特点及其对QoS的要求 ,提出了一种将多媒体通信服务质量 (QoS)控制和基于速率拥塞控制结合起来的拥塞控制的新机制 .本文详细地研究了这一机制 ,并提出了源端多媒体数据流的带宽控制策略、基于动态部分缓存共享 (DPBS)的数据包丢失控制方案和接收端计算包丢失率p的方法 .

The current stability of the Internet depends on the end-to-end congestion control of TCP based on the Additive In-crease Multiplicative Decrease(AIMD)algorithm.The current TCP congestion control is appropriate for applications such as bulk data transfer，but not for real-time applications as multimedia communications.Most of existing congestion control works are suitable for the best effort flows，but not for the flows with QoS requirements.In this paper，the congestion control issue of different classes of data flows in the Internet between sender and receiver is investigated.By adopting equation-based rate control(EBRC)for differentiated services instead of traditional TCP congestion control for best-effort service，a new congestion control mechanism for multimedia communications with QoS requirements can be achieved.A dynamic partial buffer sharing scheme(DPBS)for packet loss control and a method of cal-culating the packet loss rate by receiver are proposed in this paper.Finally，the system architecture of the new congestion control mech-anism is described.