Towards Improved Overlay Simulation Using Realistic Topologies Gert Pfeifer, Ryan Spring and Christof Fetzer Appeared in: 8th IEEE International Symposium on Network Computing and Architectures (IEEE NCA09) Date: July 2009 Download: BIBTEX (pfeifer2009nca) Simulation of distributed applications and overlay networks is challenging. Often the results generated in simulation do not match experimental results. Distributed testbeds like Planet-Lab help to bridge the gap, but they do not offer enough nodes to do an Internet scale evaluation. In this paper we use a tool called TopDNS for generating realistic topologies for simulations, using the Planet-Lab to collect measurement data.We show, that simulation results may differ significantly from earlier results using synthesized topologies. We provide a data analysis to explain the observed results and to provide a better understanding of latency between hosts in certain DNS name spaces.