快速收敛的高速网络可变结构拥塞控制协议

Convergence time improved variable-structure congestion control protocol for high-speed networks

针对可变结构拥塞控制协议(VCP)存在粗粒度的拥塞反馈信息和收敛速度慢等问题,采用动态拥塞窗口控制和收敛控制器2种机制,提出了一种扩展的可变结构拥塞控制协议(EVCP).EVCP通过复用Ipv6报文头的4个二进制位提高拥塞反馈信息的粒度,并基于实时的拥塞反馈信息实现动态拥塞窗口控制.收敛控制器的基本思想是如果EVCP传输流的拥塞窗口大于公平的拥塞窗口,当积性减少时,该传输流需要比往常更积极地减少拥塞窗口.仿真表明,EVCP不仅保持了VCP的优点,而且在公平性和收敛速度方面具有更好的性能.

In order to solve the problems of variable-structure congestion control protocol （VCP） such as coarse-granularity congestion feedback and poor convergence, an extended variable-structure congestion control protocol （EVCP） was proposed, which adopts two mechanisms, i.e. dynamic congestion window control and convergence controller. EVCP uses the four bits of Class of Traffic segment in Ipv6 header to improve the granularity of congestion feedback, and it realizes the dynamic congestion window control based on the real-time congestion feedback. The basic idea of the convergence controller is that if a flow has larger window than its fair window, its congestion window should be decreased more aggressively than usual in multiplicative decrease （MD） phase. Simulation verifies that EVCP can achieve better fairness and faster convergence while still keeps the advantages of VCP.