EBM: A New Approach for Scalable DiffServ Multicasting

The phenomenal growths of group communications and QoSaware applications over the Internet have respectively accelerated the development of two key technologies, namely, multicasting and Differentiated Services (DiffServ). Although both are complementary technologies, their integration is a non-trivial task due to architectural conflicts between them. In this paper, we propose a new approach, Edge-Based Multicasting (EBM), for providing multicast transport across a DiffServ domain. EBM leverages the intelligence of edge routers in DiffServ and a new entity called a Multicast Broker (MB) to provide such services. Unlike traditional IP multicast, our approach keeps core routers stateless and multicast-unaware. Our approach has significant implications for multicasting regarding scalability, deployment, security, heterogeneous users, and resource management. In our paper, we outline the EBM model and propose a novel tree construction algorithm, Edge Cluster Trees (ECT), which captures the unique aspects of DiffServ and EBM. Finally, we present detailed simulation studies of our approach and contrast our approach versus previous work.