GSS:针对高带宽时延积网络的温和慢启动方法

GSS:A Gentle Slow Start Strategy for High-Bandwidth Delay Product Networks

高带宽时延积的网络往往拥有很大慢启动阈值。在"慢启动"后期,TCP的指数增长策略往往使"拥塞窗口"在一个往返时延(RTT)后增大很多。这容易导致网络拥塞,对数据传输量较小的应用(如http业务)尤其有害。本文提出了一种温和的慢启动策略GSS。当拥塞窗口较小时,以接近指数的方式增长;随着窗口的变大,逐渐放缓增长速度,最终平滑过渡到"拥塞避免"阶段。NS2仿真结果显示,GSS相对原始的慢启动拥有较高的瓶颈利用率、较小的队列长度和丢包率。

High-bandwidth delay product （HBDP） networks often have a very big slow-start threshold. In the slow start phase, the current TCP＇ s exponential increase strategy often increases the congestion window immensely after one round trip time. This easily results in network congestion and especially harms the short traffic which transfers few data, such as http. In this paper, we present a new slow-start strategy called GSS （Gentle Slow Start）. When the congestion window size is small, the increase policy of GSS isnear the original exponential method; while the window size becomes bigger, the increase slows down and finally smoothly switches to the congestion avoidance phase. The NS2 simulation results show that GSS has higher bottleneck utilization, a smaller queue size and lower drop rates than slow start.