Hierarchical overlay multicast based on host group model and topology-awareness

We propose a scheme for hierarchical overlay multicast based on IP topology awareness and host group model called PAM (practical topology-aware overlay multicast). PAM is remarkably different from the previous overlay multicast or ALM (application layer multicast) schemes in the following aspects. First, instead of end-host, DR (designated router) builds overlay DDT (data delivery tree) by adopting host group model [C. Diot et al., Jan.-Feb. 2000], in order to improve scalability within a subnet, robustness of group members and transparency compatible with traditional multicast. Second, hierarchical overlay tree is constructed. That is, intra-domain DDT and inter-domain DDT are built hierarchically for more scalable and practical deployment. In addition, PAM constructs overlay DDT with IP topology information derived from DRs to localize group members and gain performance enhancement such as low first join latency and reduced control overhead. Compared with other principle ALM schemes, those distinct advantages of PAM are evaluated by simulation