Scalable Application-Layer Multicast Simulations with OverSim

Application-Layer Multicast has become a promising class of protocols since IP Multicast has not found wide area deployment in the Internet. Developing such protocols requires in-depth analysis of their properties even with large numbers of participants-a characteristic which is at best hard to achieve in real network experiments. Several well-known simulation frameworks have been developed and used in recent years, but none has proved to be fitting the requirements for analyzing large-scale application-layer networks. In this paper we propose the OverSim framework as a promising simulation environment for scalable Application-Layer Multicast research. We show that OverSim is able to manage even overlays with several thousand participants in appropriate processing time while consuming comparably little memory. We compare the framework´s runtime properties with the two exemplary Application-Layer Multicast protocols Scribe and NICE. The results show that both simulation time and memory consumption grow linearly with the number of nodes.