Placement of Proxy Servers to Support Server-Based Reliable Multicast

Raja Jothi and Balaji Raghavachari Department of Computer Science, University of Texas at Dallas Richardson, TX 75083, USA fraja, [email protected] Abstract—We consider the problem of placing k proxies on a n node network to support server-based reliable multicast. Typically, in a multicast connection, the sender transmits information to all the receivers in the multicast group. Failures in transmission causes receivers to send retransmission requests to the sender. Due to high retransmission requests, the sender could become a potential hot-spot in the network. Also, receivers far away from the sender could experience high delays in receiving the retransmitted information. To prevent these and other issues, the notion of placing proxy (or repair) servers across the network was introduced, so that receivers could send their retransmission requests to the nearby proxy servers than to the source. In this context, we consider static placement of proxies on a network in which multicast requests (trees) are generated dynamically. The placement of proxies should be such that the proxies are utilized efficiently by the dynamically generated multicast trees. In this paper, we present three heuristics for efficient placement of proxies on any given network. We compare the performance of our heuristics with the best available heuristic KMPC, due to Lin and Yang, as well as the random proxy placement heuristic. Experiment results show that one of our heuristics, the NASPC, outperforms all the other heuristics with respect to all performance measures considered.