NEmu: A distributed testbed for the virtualization of dynamic, fixed and mobile networks

Experimentation is typically the last step before launching a network application on a large production scale. However, it is often difficult to gather enough hardware resources for experimenting with a reasonably sized distributed application inside a controlled environment. Virtualization is thus a handy technique for creating such an experimentation testbed. We propose a tool called NEmu designed to create virtual dynamic networks by using emulation for testing and evaluating prototypes of networked or distributed applications with a complete control over the network topology and link parameters. NEmu leverages system emulators such as QEMU for virtualizing the hosts and the routers. It uses vnd for virtualizing components such as links and switches. In addition, NEmu allows users to create such customized topologies with limited hardware resources and without any administrative rights. We validate NEmu by replicating two network experiments and by showing that NEmu gives results very similar to the original ones.