In this paper we propose a new approach of application-level multicast protocol providing a group communication service. This protocol, called End-System Multicast (ESM), and can be used when native multicast routing is not available. ESM is a centralized protocol where everything is being controlled by a single host called Rendez-vous point (RPL1), connected indirectly to the group members via some hosts called secondary Rendez-vous Point (RPL2). Each RPL2 has some group members that constitute a cluster, and each cluster is controlled by its RPL2. Since the group control is divided among some RPL2 and a main controller (RPL1) manages the relation among RPL2 s and between itself and RPL2 s , we found that the scalability is improved and it also avoids the bottleneck problem near the RPL1, or there is a load balance.
A survey of proposals for an alternative group communication service
