基于TCP Vegas与TCP Reno的一种改进拥塞控制算法

因特网的快速发展带来了信息量的急剧膨胀，网络拥塞已经成为制约因特网发展的瓶颈。在众多TCP拥塞控制算法中，TCP Vegas表现出比其他算法更为优越的性能，然而自1995年提出至今，仍然没有取代TCP Reno成为现今最广泛使用的TCP拥塞控制算法。有研究表明，这是由于Vegas在与Reno共存的网络环境下不能公平地竞争到带宽，因此不能实实质性地提高网络性能。本文在分析Vegas与Reno如何在网络路由中占用带宽的基础上，提出一种在两者兼容环境下的拥塞控制方法，根据不同瓶颈缓冲区容量合理选择α、β等参数，实现了在Vegas与Reno共存环境下两者良好的兼容性，并通过仿真实验证明了该算法的有效性和正确性。

An Improved Congestion Control Algorithm Based on TCP Vegas and TCP Reno

Since the rapid development of the Internet brings the quick expansion of information, so network congestion has become a bottleneck. Despite the superiority of TCP Vegas which was proposed in 1995 over the other TCP congestion control algorithms, Vegas is still not the most widely used one instead ofTCP Reno. Research shows it is due to Vegas＇ incapability of seizing bandwidth fairly in heterogeneous network environments, so the overall performanc ce can not be improved essentially. In this paper, we analyze how Vegas and Reno seize bandwidth and propose an improved congestion control algorithm in the environment where Reno and Vegas coexist. By properly selecting parameters a and/3 based on different bottleneck buffer sizes,we show the good comp  atibility of Vegas and Reno and prove the efficiency and correctness of the algorithm through simulation.