以封包壓縮技術增進網路傳輸效能之研究

Efficiency Enhancement of Network Data Transmission by Packet Compression

王鼎棋(Ding-Chi Wang)

指導教授 ： 鄭福炯

大同大學/電機資訊學院/資訊工程學系所/碩士(2008年)

摘要

由於連接網際網路的電腦愈來愈多及對於頻寬的需求愈來愈高，但因IPv4位址不足的問題及頻寬昂貴，而使得網路分享器被廣泛的使用在網際網路的環境中，以達到頻寬共享及解決IPv4不足的問題，不過也因為所有的內部網路封包全部透過網路分享器轉傳封包，讓網路分享器對於整體網路傳輸效能的優劣有著很大的影響，為了提高整體網路的效能，本論文以Altera NIOSⅡ為開發平台並利用Run Length Encoding、Lempel-Ziv、Shannon-Fano、Huffman資料壓縮演算法，將封包壓縮後傳送並進行效能分析，以達到提高資料傳輸率，進而降低網路分享器的負載，讓有限的實際頻寬可以傳輸更多的資料。
我們提出多個封包壓縮的方法來提昇網路傳輸的效能，根據我們的實驗結果最高可以提昇文字類型的檔案傳輸約64.37%，我們並利用Altera 公司所提供的C2H來加速壓縮、解壓縮的速度，進而降低CPU的負載，根據我們的實驗結果，四種壓縮演算法在提高網路資料傳輸率上，以Lempel-Ziv的表現最佳，再將Lempel-Ziv以C2H 轉換成硬體執行，可提高壓縮速度5倍及解壓縮速度8倍的結果。

關鍵字

網際網路 ； 封包壓縮

並列摘要

As more and more computers are connected to the Internet, and the demand for bandwidth has been increasing, due to the shortage of IPv4 addresses and expensive bandwidth, NAT Router has been widely used in the Internet environment to achieve bandwidth sharing and resolve the shortage of IPv4. However, as the internal network packets are transmitted through the router, router has significant effect on the transmission efficiency of the overall network. To enhance the overall network efficiency, this study used Altera NIOS Ⅱ as the development platform, and utilized the data compression algorithms of Run Length Encoding, Lempel-Ziv, Shannon-Fano, and Huffman to compress the packets for transmission and performance analysis, in order to achieve higher data transmission rate, reduce the load of NAT Router, and enable the limited physical bandwidth to transfer more data.
This study proposed the method of using multiple packet compression to enhance the efficiency of network transmission. The experimental results showed that the file transmission rate could be improved for as high as 64.37 %. This study also used C2H (Altera Corp.) to accelerate the compression and decompression speed, and reduce the CPU load. According to the experimental results, among the four compression algorithms, Lempel-Ziv showed the best efficiency in improving network data transfer rate. By converting Lempel-Ziv to hardware by C2H, the compression speed could be increased by 5 times and decompression speed by 8 times.

並列關鍵字

Internet ； Packet Compression

參考文獻

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