Server Replication in Multicast Networks

This paper studies and proposes heuristic algorithms to solve the problem of replicated server placement (RSP) with Quality of Service (QoS) constraints. Although there has been much work on RSP in multicast networks, in most of them a simplified replication model is used, therefore, their proposed solutions may not be applicable to real systems. In this paper, we use a more realistic, and generalized model for replica placement, which considers the latency restriction of the receivers (QoS), bandwidth, and storage constraints of the links and nodes. We present a mathematical formulation and propose four heuristics that are benched marked using BRITE network generator, and discuss the benefits and drawbacks of the static and dynamic approaches. The proposed heuristics are experimentally compared through simulations with respect to their performance and computational complexity under different QoS constraints. The simulation results show interesting characteristics of the studied heuristics.