On constructing overlay networks to support distributed real-time virtual environment applications

Overlay networks provide an attractive solution to distributed real-time virtual applications because of their unique features of scalability, decentralization and cost effectiveness. However, overlay support for distributed real-time virtual applications remains a challenge because of two reasons: 1) Frequent update messages traveling through multiple hops can increase the network traffic and cause long communication and processing delays; and 2) Variable latencies experienced by different participants can violate their consistency requirements and affect the performance of the application. In this paper, we propose techniques that work at two levels to address this problem. First the participants are grouped according to their virtual distance to satisfy their consistency requirements. Second, filters that combine application-level knowledge are utilized at boundary nodes to eliminate unnecessary message propagations. Our approach enables nodes to trade-off processing overhead for consistency precision, while reducing the message overhead in the overlay network.