支持最少速率保证的UDP拥塞控制机制

THE ADAPTIVE UDP CONGESTION MECHANISM WITH THE MINIMUM RATE GUARANTEES

虽然目前 TCP流量在整个 Internet流量中占有主要地位 ,但随着网络带宽的不断升级改造 ,基于 UDP的音频、视频等实时多媒体流量日益增加 ,而这些实时流量一般都需要一定的带宽保证 ,同时又具有 TCP友好的端端拥塞控制机制 .从端主机和网关队列机制两方面着手 ,提出了一种支持 IETF定义的可控负载服务机制 ,其实现原理是在端主机方配置基于令牌桶的自适应的支持标记的速率调节机制 ,在网关采用加强的 RED(随机早期检测 )队列管理机制对不同的流量进行相应的处理 ,然后在 NS仿真环境下对其公平性、带宽使用效率等方面进行实验 。

With the increasing of real time multimedia traffic in Internet, such as video and audio applications, the end to end congestion control is becoming more and more important.The applications based on UDP generally need minimum rate guarantees and they must support tcp friendly congestion control in order to avoid congestion collapse. In this paper, a congestion scheme is presented, which supports minimum rate guarantees. The mechanism includes the end to end congestion control and the gateway queue management. The end host provides packet policing and marking function through token bucket, and the enhanced RED gateway differentiates the marked and unmarked packets. The experimental results are shown and the performance evaluation is presented by comparing the mechanism with relative schemes. This mechanism is proved to be feasible and fair.