Network virtualisation for transparent testing and experimentation of distributed applications

Popular network simulation tools, such as ns-2, are useful for undertaking experiments with emerging networking technologies. As networked applications become distributed at scales comparable to the Internet, such as peer-to-peer applications, testing and experimentation becomes increasingly difficult and important. With this paper, we are introducing an elaborate extension to existing simulation capabilities by allowing realistic highly distributed application prototypes to be attached to a simulator for transparent testing and experimentation. We enable developers to focus on building their applications rather than detailing simulation scripts. Testing can then be performed in a natural setting. PDNS is a parallel and distributed version of the commonly used ns-2 simulation package. We describe our extensions to the PDNS simulator which allow real application prototypes to be run across a simulated network. We describe our use of virtualisation as a means for sending an application´s network traffic through the simulator. Our implementation allows for large scale simulations with thousands of real peers and hundreds of thousands of simulated nodes in a network, thus we can test real peer-to-peer software at large scales.