Proxy location for minimizing delivery delay in HRM networks

In hierarchical reliable multicast schemes, the number of repair proxies and their locations influence the delivery delay. Low delivery delay is essential for the transmission of real time media. In this paper, we propose a method to decide optimal locations of repair proxies that minimize the mean delivery delay of all receivers in heterogeneous networks using a dynamic programming approach. Additionally, we evaluate how well the optimal proxies endure the link fluctuations. The evaluation results of our proposal in a simulation topology show that the mean delivery delay of all receivers can be reduced by about 10ms in network size of 1000 nodes. Moreover, we show that if an optimal proxy set is configured once and if an application can tolerate a mean delivery delay increase of 2.5 ms, the proxy set can sustain about 200% fluctuation of link statistics. Our method can be used by network providers in order to reduce delivery delay in their HRM network. 2007 Elsevier B.V. All rights reserved.