SBlue:一种增强Blue稳定性的主动式队列管理算法

SBlue: stabilized Blue

主动式队列管理(AQM)是 IETF 为解决 TCP 端到端拥塞控制机制存在的问题而提出的一种队列管理技术。Blue 是一种常用的 AQM 算法,它使用丢包事件和链路空闲事件来管理拥塞。相比较于 RED 算法,Blue 有很多优点,但由于缺乏早期拥塞检测机制,因此不能维持队列长度的稳定,特别是当 TCP 连接很多或 TCP 连接数发生突变时容易导致队列溢出或空闲。本文为此提出了一种增强 Blue 稳定性的主动式队列管理算法 SBlue。仿真实验表明,SBlue 能有效保持队列长度的稳定,大大减少队列溢出或空闲现象的发生。

In order to address the problems of TCP end-to-end congestion control, the IETF advocates to deploy active queue management mechanisms in the network. Blue is a popular AQM algorithm. It uses packet loss and link idle events to manage congestion. Compared with RED, Blue has many advantages. But because of lacking incipient congestion detecting mechanism, it suffers from queue size oscillations. Moreover many active TCP connections in the router or the variety of the number of active TCP connections will lead to queue overflow and underflow. A new AQM algorithm named “SBlue” (stabilized Blue) is proposed. Simulation results indicate that SBlue can effectively stabilize the queue occupation at a level independent of the number of active TCP connections and mitigate the queue overflow and underflow.