在無線區域網路中TCP Westwood及相關協定的效能評估

Performance Evaluation of TCP Westwood and Variants over Wireless LANs

蕭琥(Hu Hsiao)

指導教授 ： 陳建華

大同大學/電機資訊學院/通訊工程研究所/碩士(2006年)

摘要

在這次研究中我們探討的是只須在TCP來源端做改變的TCPW。基本上它與TCP Reno不同於TCP擁塞控制演算法。其設計為AIAD演算法，而不是AIMD法。
這個模擬模型是建構在會遺失封包的無線區域網路通道上。經由ns-2的模擬結果顯示，TCPW在會大量遺失封包的無線區域網路中，其平均吞吐量優於TCP Reno。同時也顯示TCPW在有瓶頸頻寬及緩衝記憶體不足的環境中有好的表現。

關鍵字

TCP Westwood

並列摘要

In this thesis we studied the TCPW which requires modifications only in the TCP stack at the source node. Basically it differs from TCP Reno in the TCP congestion control algorithm. It was designed by following the principle of Additive Increase Adaptive Decrease (AIAD), not that of additive increase multiplicative decrease (AIMD, used in TCP Reno.
Our simulation considers both the core links and the WLANs. The results show that, TCP Westwood (TCPW) outperforms TCP Reno in terms of average throughput when bursty losses occurred over the wireless channel. The results also show that TCP Westwood (TCPW) is better under bandwidth bottleneck and limited buffer size.

並列關鍵字

TCP Westwood

參考文獻

[1] V. C. Cerf and R. E. Kahn, “A protocol for packet network interconnections,” IEEE Transactions on Communications, vol. COM-22, no. 5, pp. 637-648, May 1974.

[2] V. Jacobson, “Congestion avoidance and control,” ACM Computer Communications Review, vol. 18(4) : 314 - 329, August 1988.

[4] T. Bonald, “Comparison of TCP Reno and TCP Vegas: efficiency and fairness,” In Proceedings of PERFORMANCE'99, Istanbul, Turkey, October 1999.

[5] U. Hengartner, J. Bolliger, and T. Gross, “TCP Vegas revisited,” In Proceedings of IEEE INFOCOM'2000, Tel Aviv, Israel, March 2000.

[7] L. Kalampoukas, A. Varma, and K. K. Ramakrishnan, “Explicit window adaptation: a method to enhance TCP performance,” In Proceedings of IEEE INFOCOM'98, San Francisco, Ca, USA, March/April 1998.