关键词: 拥塞窗口, 高速网, 吞吐量, 非线性方式, 慢启动, 稳定性, 公平性, 友好性

Abstract: Congestion window of TCP Westwood (TCPW) is based on the increase of linear mode at the congestion avoidance phase in high-speed networks. Therefore, it cannot rapidly obtain or maintain the high throughput. During the slow-start stage, the congestion window of TCPW is based on exponential growth mode, which will cause the datagram increases too fast and prompt the probability of congestion. For the above defects, TCPW was improved from two aspects, and the new algorithm was called NLTCPW. During the slow-start stage, send window of NLTCPW got 10 packets faster than TCPW. After that, the increment speed of send window was decelerated. A simple nonlinear mode was used to increase the congestion widow at the congestion stage. The performance analysis of mathematical model and simulation results show that NLTCPW algorithm has better throughput performance, lower packet loss rate and better fairness, and it is friendly and stable in high-speed networks.

Key words: congestion window, high-speed network, throughput, nonlinear mode, slow-start, stability, fairness, friendliness