دانلود رایگان مقاله NEmu: بستر آزمایشی برای مجازی سازی پویا، ثابت و شبکه تلفن همراه

Abstract

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.

7. Conclusion

NEmu and its associated programs vnd and nemo enable the creation and management of dynamic, heterogeneous and mobile virtual networks. They provide a good compromise between ease of use, low cost and realism. Such virtual networks can be distributed over several physical hosts and be controlled without any administrative rights. They can also evolve in real time with nemo by following a pre-calculated connectivity scenario. We have compared NEmu to Mininet with regard to the Mosh experiment and have shown that the results are nearly identical thus demonstrating that NEmu can be used for similar purposes. The advantage being that it can be distributed over several physical machines unlike Mininet. This is important as NEmu uses full system emulation and not container based emulation. We have compared NEmu to JBotSim with regard to the AMiRALE experiment and the obtained results are similar, thus validating its use for virtual mobile devices’ experimentation. NEmu can therefore overcome the cost of a physical testbed infrastructure while enabling the evaluation of real applications thanks to its low level emulation of network and system components. NEmu can also emulate mobile ad hoc networks which, as far as we know, is a unique feature among network emulators.