On overlay multicast tree construction and maintenance

Overlay multicast tree construction and maintenance is a major challenge in designing application layer multicast protocols. In this paper, we focus on improving the joining and maintenance procedures of an overlay multicast tree. Unlike the existing direct-tree protocols, our proposed overlay multicast tree protocol (OMTP) has the following characteristics. First, by leveraging on the IP hierarchical addressing locality, we can speed up the formation of overlay multicast tree and enhance the efficiency of the tree maintenance. Second, we take both bandwidth availability and round-trip-time (RTT) into consideration when a newcomer selects its parent node. Finally, an effective mechanism is designed to disperse the simultaneous rejoin crowds in the tree repair phase. Simulation results show that with our proposed protocol, the join latency can be reduced by as large as 50% as compared with a popular direct-tree protocol HMTP