近幾年，利用在點對點網路(peer-to-peer networks)的環境中架設隨選視訊系統服務 (VoD service) 已經漸漸的成為了一種吸引人而且熱門的多媒體串流服務的提供方式。由於這樣的網路架構提供了一種能夠降低成本而且容易架設的特性，網路上的客戶端緩衝部分的影片片段，然後用來供應其他客戶的視訊要求，使得串流的服務範圍能夠擴展。愈來愈多的人開始研究如何在不同的點對點網路中(包含結構式以及無結構式的點對點網路系統)建構出有效率且高延展性的系統。在之前提出過的研究中，我們發現大部分提出的系統很少討論到在這樣的應用中如何去作搜尋的動作，這些系統大部分假定有一個類似目錄索引的方式可以讓使用者找到一個適合的串流服務提供者。如此一來，可能使得系統成為一個非完全分散式的環境，並造成當網路規模擴大時而造成的瓶頸。
在這篇論文中，我們提出了一個在VoD service 的應用環境中，一種適合分散式多媒體串流系統的搜尋方式。我們利用streaming chaining的特性，將網路中所有的使用者連結成為一個類似“mesh”的網路架構，當使用者在系統中作搜尋或是錯誤修復的時候，都能利用較少的訊息量而且適當的時間內去完成使用者的需求。即使在系統中有大量不穩定的使用者，系統仍然可以順利的運作。在論文的最後，我們也提出了一連串的實驗，證明了系統在不同情況下的能力。

Video-on-demand (VoD) services based on the peer-to-peer (P2P) approach become very attractive in recent years, due to the simplicity and low-cost in deploying the system. In a P2P video delivery system, the video stream needed by a peer is supplied by one or more peers, which cache the needed segments. However, most of the previous systems did not address the supplier discovery issue. They mainly assumed there is an index service for peers to query the suppliers in the systems. In this thesis, we consider a streaming system in which a streaming chaining system is built on top of a fully decentralized P2P network. As peers join or fail in the system, a decentralized algorithm using a special peering structure is used for supplier recovery. This structure can reduce the message overhead in discovering the suppliers and enhance the query successful rate. We have conducted simulation to evaluate the performance of the proposed system.

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