Internet的TCP拥塞控制机制改进

Improvement of TCP Congestion Control in the Internet

随着视频点播等网络多媒体技术的快速发展 ,现有的TCP拥塞控制机制已不能有效解决网络拥塞问题 .为了改善这种状况 ,可以通过改进现有的算法来获得较好的性能 .合适字节计数(ABC)算法通过改进拥塞窗口的增长方式减轻延迟或丢失的确认 (ACK)带来的负面影响 ,填补了TCP协议中的一个漏洞 .此外 ,适当地增加初始化窗口可以减少传输时间 ,提高性能 .尽管算法的改进一定程度上能缓解网络的拥挤状况 ,但仍有些问题无法解决 ,拥塞管理器则集成了所有应用程序及传输协议 ,用于进行拥塞控制和管理、带宽共享等 ,也就有可能彻底。

With the rapid development of multimedia technology, it is time to improve curre nt Congestion Control. Rather than the traditional method, ABC (Appropriate Byte Counting) suggests basing the increase on the number of previously unacknowledg ed bytes each ACK(Acknowledgement) covers. This change improves the performanc e of TCP, as well as closes a security hole TCP receivers can use to induce the sender to increasing the sending rate too rapidly. Besides, increasing the TCP i nitial window to three packets (or 4380 bytes) helps to improve perceived perfor mance. To improve the performance, CM (congestion manager) is designed to allow application to easily adapt to network congestion and enable proper congestion c ontrol.