A middleware approach for supporting application-level multicast services

Application-level multicast (ALM) is a novel technology for multipoint applications, such as large scale file distribution, video and audio streaming, and video conference. Though several ALM systems have been proposed, all the multicast functions have been independently developed and integrated into individual applications. In such a situation, the development includes a lot of redundancy. Our goal is to develop RelayCast, the middleware which provides the common functions of ALM to eliminate the redundancy. RelayCast has some functional units which support fundamental and minimum functions respectively, and realizes one complete ALM system by cooperation of the units. The functional unit contains several components with different algorithms, and RelayCast meets the requirements of various applications by choosing the appropriate component. In this paper, we propose the RelayCast architecture, and present the implementation and experiment of a prototype.