RelayCast: a middleware for application-level multicast services

Application-level multicast (ALM) is being increasingly recognized as a solution to support multipoint applications without the need for a network layer multicast protocol. Though several ALM systems have been proposed, all the multicast functions are independently developed and integrated into individual applications. However, we can find out the common functions of ALM among the existing systems. Our goal is to abstract the common functions and incorporate them in the middleware called RelayCast. RelayCast meets the fundamental requirements of various applications by combining several components of ALM functions. In this paper, we firstly present the architecture and implementation of RelayCast. Then, we present the multipath routing mechanism as a component. The multi-path routing achieves fast tree rebuilding at the time of tree partition caused by end-host´s leave or failure.