具階層式架構之群播管理伺服器的設計與實作

Abstract

視訊會議系統是一項多媒體網路的重要應用。由於視訊會議系統需要一 種較特別且傳統網路尚未提供的傳輸服務—群播傳輸。在本論文中，我們 針對視訊會議系統，發展了一個群播管理伺服器，此群播管理伺服器將全 部的群播成員建構成一個群播樹，並且在每一個有群播成員的子網路（ subnet）上，選定一個成員擔任代理人（agent），這些代理人具有轉送 （forward）其所產生或收到的群播封包給下一個代理人之功能，及廣播 此群播封包給其子網路上的其他成員，來達成群播的目的。除此之外，我 們也利用此群播管理伺服器開發了一套視訊會議雛形系統。 Video conference is one of the most important applications of multimedia network. It needs a special transmission service, multicast, which is not supported by a general network. In this thesis, a multicast management server(MMS) is developed for a video-conferencing system. The MMS is used to construct the multicast group as a multicast tree and to choose a member on each subnet as an agent. The agent may forward the received packets to next agent and broadcast the packets to other members in the subnet, and thus the multicast is performed. In addition, a prototype of a video-conferencing system is implemented.