設計與實作基於rwnd的CMT-SCTP傳輸機制

Design and Implementation of CMT-SCTP Based on the Received rwnd

黃柏勛(Po-Hsun Huang)

指導教授 ： 張林煌

朝陽科技大學/資訊學院/網路與通訊研究所/碩士(2009年)

摘要

IETF提出的Stream Control Transmission Protocol (SCTP)能夠有效改善Transmission Control Protocol(TCP)在資料傳輸效率與安全性的問題。但是，SCTP的傳輸機制就像TCP一般，只能使用單一路徑進行傳輸，所以，無法有效的運用其他網路的資源。因此，相關研究學者他們提出SCTP使用多路徑同步傳輸機制來提升傳輸效能，並考慮了各種網路因素，如頻寬、封包遺失率、延遲等作為分配封包的順序，但是，他們並未考慮平均速率和接收端(receiver window, RWND)對於負載均衡在CMT影響。故在本論文中，我們修改標準SCTP傳輸機制並提出(Arrival Rate Dependent- Concurrent Multi-path Transfer)ARD-CMT傳輸機制，由原本的單一路徑傳輸，修改成多路徑傳輸的設計架構，並且實作在linux系統上，ARD-CMT傳輸機制除了能夠提升傳輸效能之外，更能夠基於接收端的RWND和發送端的平均速率來計算權重，使ARD-CMT基於此權重達到負載均衡。最後，在實驗的部分，我們使用NIST NET來模擬現實環境的干擾因素，並經由實驗證明我們提出的ARD-CMT傳輸機制除了提升傳輸效能之外，更可以提供良好的封包排程機制，並達到負載均衡之目的。

關鍵字

封包排程 ； CMT ； Linux ； 效能 ； SCTP

並列摘要

The Stream Control Transmission Protocol (SCTP) proposed by IETF can improve problems in efficiency and security of TCP over network of transmitting data. But, SCTP transmission mechanism likes TCP, SCTP only use a single path to transmission, so, the utilization of network cannot be improved efficiently. Hence, research scholars proposed SCTP used concurrent multi-path transfer mechanism to increase the transmission performance, and they consider many network factors, ex: bandwidth, packet loss rate, delay, but, they do not considering load balancing in the CMT influences on average rate and receiver RWND. In this thesis, we modify the standard SCTP transmission mechanism, and we proposed ARD-CMT transmission mechanism to transfer data in different path, then, we implementation the ARD-CMT system on the linux platform, ARD-CMT transmission mechanism can increase the transmission performance, ARD-CMT based on the receiver RWND and average rate to calculation the weight. ARD-CMT based on the weight to achieve load balancing scheme. Finally, we used NIST NET to simulate environment factors reality, the simulation result shows that the ARD-CMT transmission mechanism can promotes the transmission performance, ARD-CMT provide a good mechanism for packet scheduling to achieve load balancing scheme

並列關鍵字

CMT ； packet scheduling ； Linux ； performance ； SCTP

參考文獻

[27]L.H. Chang, D.J. Wang and K.C. Lai, "Network Gateway Design and Implementation Using Dynamic Load Balancing", Journal of Internet Technology, v5, No.1, pp. 19-25, 2004.

[1]J. Postel, “Transmission Control Protocol,” IETF RFC 793, September 1981.

[2]J. Postel, “User Datagram Protocol,” IETF RFC 768, August 1980.

[4]S. Fu, and M. Atiquzzaman, “SCTP: State of the Art in Research, Products, and Technical Challenges,” Communications Magazine of IEEE, Vol. 42, Issue 4, pp. 64-76, April 2004.

[5]R. Stewart and Q. Xie et. al., ”Stream Control Transmission Protocol,” IETF RFC 2960, October 2000.