具快速恢復特性之多源應用層群播影音串流系統之研製

近年來，P2P (Peer-to-Peer)網路技術已發展穩定，許多人使用P2P網路技術來觀看或下載重播的電視節目、電影或是電視直播、重要頒獎典禮等。P2P的特點在於資源共享的權力是在各個用戶手上而非單一網站，而技術的應用使得網路上的資源得以共享並得到充分利用。著名的P2P系統可分為四類:分別為「文件共享類系統」、「即時通訊類系統」、「串流媒體類系統」及「共享儲存類系統」，較廣為人知的軟體則有eMule、Skype、PPStream、Grannary、…等。本論文研究是基於ALM(Application Layer Multicast)技術，新成員加入群組後與群組中的每位成員建立互連關係，並計算與每位成員之間的距離，產生樹狀的傳輸路徑，新成員被建立在Multicast group members中，則可以有效的減少因為新的節點加入或是舊節點的斷線與離開時調整樹狀路徑的時間。因此本論文實作Distributed Multisource Forwarding Trees (DMFT) 及Cluster Distributed Multisource Forwarding Trees (CDMFT) 演算法改善ALM傳輸方式，進行多媒體資料傳輸的系統，透過快速節點恢復的特性，使得網路影音能夠更為順暢。

關鍵字

對等式網路；多媒體串流；多源群播；應用層群播

並列摘要

Peer to Peer (P2P) technique over internet had been developed for years. Currently, watching TV shows, movies, or even the live video through P2P-based applications are very common things. P2P applications can be divided to four types: file sharing systems (e.g. Bit Torrent), instant messaging systems (e.g. GTalk), media streaming systems (e.g. PPLive), and storage sharing system (e.g. Grannary). One of the most important characteristics in P2P technique is sharing data efficiently, every client can share data to each other instead of getting data from the same source, and this technique makes the resource get higher usage. This thesis realized two ALM algorithms to deal with issues of recovery time and multisource. The Distributed Multisource Forwarding Trees (DMFT) and Cluster-based Distributed Multisource Forwarding Trees (CDMFT) were implemented and tested. The key performance measured is the recovery time for the delivery of multicast media data when a group member in a multicast group either joins or leaves the group.