shadow: runs real applications like Tor and Bitcoin over a simulated Internet topology
The Shadow Simulator
Shadow is a unique discrete-event network simulator that runs real applications like Tor and Bitcoin, and distributed systems of thousands of nodes on a single machine. Shadow combines the accuracy of emulation with the efficiency and control of simulation, achieving the best of both approaches.
Also included are simple Internet topologies and a core plug-in for generating traffic between nodes and through SOCKS proxies.