由於網際網路的蓬勃發展，資訊可快速地被傳遞，只有文字和圖片的資訊交流，己無法滿足使用者的需求。隨著電腦相關科技的逐漸進步，如何有效地提供多媒體串流服務內容給各種不同下載頻寬的廣大群眾已經成為一項值得注意的議題。本研究主要討論在CDN-P2P(ContentDistribution Network–Peer to Peer)混合架構模式下， 以loopback 機制運用MDC(Multiple description Coding)多重描述編碼技術的概念，來解決節點網路頻寬異質性的議題，讓使用者可依需求來享有不同的隨選視訊觀看品質。本論文中，我們提出OLF(Open-Loop-First) 方法，在分配串流描述(description)時，考量Loopback機制的堅韌度(robustness) 和可用度(availability)，來提升代理伺服器(proxy server)的延展性，以提供使用者更好的多媒體傳輸服務。模擬實驗結果顯示OLF串流描述分配方法在loopback-MDC 的機制上可以有效地降低CDN-P2P 隨選視訊系統代理伺服器的上傳頻寬。Owing to the widely prevailing deployment of the Internet, the information now can be rapidly disseminated all over the world. Only the content of static texts and pictures has no longer met users’ demands. Along with the speedy advance of computer-related technologies, how to efficiently provide multimedia content for the large various crowd on the Internet, especially videos, becomes the noticeable issue. In this paper, we discuss the adaptation of MDC (Multiple description Coding) for the loopback buffering mechanism to address the issue of peer heterogeneity on CDN-P2P (Content Distribution Network–Peer to Peer) video-on-demand system. The proposed OLF (Open-Loop-First) description selection policy for a new peer takes the robustness and the availability of loopback-MDC mechanism into account to raise the scalability of proxy server. The simulation results show that the OLF with loopback-MDC can effectively reduce the amount of uploading bandwidth of a proxy on CDN-P2P video-on-demand system.
