高带宽延迟网络中路由器缓存需求的仿真分析

Simulation and Analysis of Router Buffer Requirements in High Bandwidth-Delay Networks

文中针对当今高带宽延迟网络下路由器缓存大小的需求问题,通过NS2仿真实验,对基于TCP协议模型的5种典型的缓存设置方法展开研究,着重分析了在高带宽延迟网络下各种高速TCP协议和主动队列管理(AQM)机制对各种缓存设置方法的影响.仿真实验表明:基于不同假设前提的缓存设置方法适应于不同的网络负载环境;缓存机制的选择取决于网络带宽延迟乘积与流数的比值;在高带宽延迟网络下,当采用高速TCP协议和AQM机制时,缓存需求可以大大减小.

In order to meet the requirement for router buffer size in high bandwidth-delay networks, five typical buffer-sizing methods based on the TCP model are analyzed via the NS2 simulation, and the effects of various highspeed TCP protocols and active queue management （AQM） mechanisms on the buffer-sizing methods in high bandwidth-delay networks are discussed in detail. Simulated results show that ： （ 1 ） the buffer-sizing methods based on different assumptions adapt to different network environments; （2） the validity of the existing cache mechanisms depends on the ratio of the bandwidth-delay product to the flow number; and （3） when high-speed TCP protocols and AQM mechanisms are used in high bandwidth-delay networks, the buffer size is greatly reduced.