中文摘要：

目前TCP协议中的慢启动门限是一个固定值，所以它不能有效的适应网络状态的变化，容易出现由于慢启动过程过早或者过晚结束，进而导致拥塞崩渍或者网络吞吐量下降。文章提出一种基于往返时延（RTT，round．triptime）的慢启动算法，在该算法中，慢启动门限将根据当前网络的RTT进行动态调整。仿真结果表明，它能有效的在网络拥塞状态下减少拥塞崩溃，以及在网络理想情况下提高网络的吞吐量。

英文摘要：

The slow-start threshold in TCP protocol is a fixed value, so it can not effectively adapt to the changes of network state and it is prone to ending the slow start too early or too late, which causes congestion collapse or throughput degradation. This paper proposed a slow-start ＇algorithm based on the round-trip time, and in this algorithm the slow-start threshold would be adjusted according to the current RTT of network. The simulation results show that the algorithm can effectively reduce the congestion collapse in a congestion state and improve the throughput in a good network state.