What is Application-Layer Multicast (ALM)

In the network level computer group-communication (one-to-many) technology, IP-multicast contributes significant roles in enhancing the physical network scalability by replicating identical packets at routers. However, since its initial proposal the IP-multicast has not been widely enabled due to the slow pace of its deployment. Hence, the application-level multicast (ALM) concept emerged to solve this deployment issue by shifting the multicast support from routers to end-systems. The article reviews the most important facts of the Application-Level Multicast and its proposed models. Furthermore, the article describes a novel concept of modeling relative density of members called bunched mode and a proposed host-end multicast transport protocol called shortest tunnel first (STF). The bunched mode is based on the thematic multicast concept (TMC), which means that it is a typical multicast scenario where there are a lot of interested hosts in certain institutes and these institutes are relatively far from each other. The developed analysis tool NetSim and the implementation of the TMC called PardedeCAST are also presented as the tools of this research.