A P2PSIP Demonstrator Powered by OverSim Ingmar Baumgart, Bernhard Heep, Stephan Krause Institute of Telematics Universit¨at Karlsruhe (TH) Zirkel 2, D–76128 Karlsruhe, Germany Email: {baumgart, heep, stkrause}@tm.uka.de I. INTRODUCTION A fundamental problem in studying peer-to-peer networks is the evaluation of new protocols. This commonly involves both the simulation of the protocol in a large-