隨著網路技術的蓬勃發展，使得資訊內容的傳播及交換次數越來越頻繁；加上多媒體應用技術的推波助瀾，豐富了資訊內容與複雜度。然而，隨之而來的服務，亦發展出許多專門的內容派送系統以供網路內容傳送。
而一般作用於商業用途的內容派送系統，所採用的架構仍是屬於傳統用戶端-伺服器端(Client-Server)架構，並且依據會員的層級不同，授予不同的分級服務。伴隨著使用人數的增加以及內容資訊的豐富化，使得內容派送系統業者面臨了三個問題：系統使用者的增加，使得伺服器端頻寬大量消耗，而且伺服器端的上傳頻寬時常成為傳輸瓶頸。分級服務中，為保證高級會員的傳輸頻寬，勢必降低一般會員的頻寬使用量，此舉將降低一般會員的使用意願。分級服務中，服務質量 (QoS, Quality-of-Service) 的服務會因為伺服器的繁忙以及網路的不穩定性等因素而無法在伺服器端有效落實。
因此，本論文為依據一般業界標準而設計、實作出的一個完整的內容派送系統，它同時滿足以下幾項需求：將察覺服務質量 (QoS-aware) 的機制在客戶端實現，以提供更完整的服務品質。提供一個完整的應用程式介面 (Application Programming Interface)，主要為做為本系統在客戶端與其他應用程式軟體銜接的橋梁，提供點對點網路基礎 (Peer-to-Peer Basis)，將系統用戶加入同儕網路中，以提升傳輸的品質，並同時紓緩伺服器端頻寬的窘境，並大大減少系統建置的成本。

With rapid development of network technique, communication and exchange for contents of information are increasingly frequent; along with applications of multimedia, it also enriches and complexes the content of information. Moreover, it has developed a number of specialized content delivery systems for Internet content delivery.
The general content delivery system for commercial purpose is still adopted architecture of Client-Server, which bases on central servers to provide different level of membership and classification of different services. Accompany with increment of the number of users and enrichment of content of information, lead content delivery system industries to face some issues. The increment of the number of users, leads to large number of consumption of server-side bandwidth. Moreover, the upstream of server-side bandwidth is often a transmission bottleneck. To guarantee the transmission bandwidth of the senior members reduces the bandwidth usage of the general members, which will lower the general members’ willing in grading service. Quality of Service (QoS) is ineffectively implemented in the server side because of bustling servers and instable network.
This thesis is based on general industrial standards and designed to actually implement a complete content delivery system, which must meet the following requirements. Realize the QoS-aware mechanism in client side to provide more complete quality of service. Provide a complete application programming interface for reference to other client application software. Provide a Peer-to-Peer basis to alleviate the consumption of server-side bandwidth and cost of system construction.

[1]. Content Delivery Network. http://en.wikipedia.org/wiki/
[2]. Stefan Saroiu, Krishna P. Gummadi, Richard J. Dunn, Steven D. Gribble, and Henry M. Levy. “An Analysis of Internet Content Delivery Systems”, ACM SIGOPS Operating Sytem, ISSN: 0163-5980, Nov. 2002.
[3]. Ipoque, http://www.ipoque.com/
[4]. Gnutella, http://en.wikipedia.org/wiki/Gnutella
[5]. BitTirrent, http://www.bittorrent.com
[6]. eMule, http://www.emule-project.net
[7]. GoGoBox, http://www.gogobox.com.tw
[8]. Agile Software Development, http://agilesoftwaredevelopment.com/
[9]. Ms. MAY PAING PAING ZAW and Ms. SU MYAT MARLAR SOE. “Design and Implementation of Client ServerNetwork Management System for Ethernet LAN”, World Academy of Science, Engineering and Technology 48 2008.
[10]. Rui He; Man Yuan; Jianping Hu; Hong Zhang; Zhigang Kan; Jian Ma. “A novel service-oriented AAA architecture”, Sch. of Comput. Sci., Beijing Univ. of Aeronaut. & Astronaut., China, Sept. 2003.
[11]. Tian M, Gramm A, Ritter H, Schiller J. “Efficient selection and monitoring of QoS-aware Web services with the WS-QoS framework”, In: Liu J, Cercone N, eds. Proc. of the IEEE Int'l Conf. on Web Intelligence (WI 2004). New York: IEEE Press, 2004. 152-158.
[12]. Yu T, Lin KJ. Service selection algorithms for Web services with end-to-end QoS constraints. In: Hsu MC, Zhang LJ, eds. Proc. of the IEEE Int'l Conf. on E-Commerce Technology (CEC 2004). New York: IEEE Press, 2004. 129-136.
[13]. The Pirate Bay, the world’s largest BitTorrent tracker. http://thepiratebay.org/
[14]. Xiangying Yang; de Veciana, G. “Service capacity of peer to peer networks”. Dept. of Electr. & Comput. Eng., Texas Univ., Austin, TX, USA. INFOCOM 2004. Twenty-third AnnualJoint Conference of the IEEE Computer and Communications Societies
[15]. IETF, http://www.ietf.org/
[16]. W3C, http://www.w3.org/
[17]. XML, http://docstore.mik.ua/orelly/perl3/pxml/ch09_01.htm
[18]. SOAP, http://www.w3schools.com/soap/
[19]. Butterworth-Heinemann Newton, MA, USA, “Analysis of hybrid P2P overlay network topology”, Computer Communications, Volume 31, Issue 2. February 2008.
[20]. Bandwidth monitor, http://www.bwmonitor.com/
[21]. NetLimiter, http://www.netlimiter.com/
[22]. Flashget, http://www.flashget.com/
[23]. Leaky Bucket Algorithm, http://msdn.microsoft.com/en-us/library/.