Résumé: During the development of network protocols and distributed applications, their performance has to be analyzed in appropriate environments. Network emulation testbeds provide a synthetic, con.gurable network environment for comparative performance measurementsof real implementations. Realistic scenarios have to consider hundreds of communicating nodes. Common network emulationapproaches limit the number of nodes in a scenario to the number of computers in an emulation testbed. To overcome this limitation, we introduce a virtual node concept for network emulation. The key problem for node virtualization is a transparent, yet e.cient separation of node resources. In this paper, we provide a brief survey of candidate node virtualization approaches to facilitate scalable network emulation. Based on the gathered insights, we propose a lightweight virtualization solution to achieve maximum scalability and discuss the main points regarding its implementation. We present extensive evaluations that show the scalability and transparency of our approach in both a traditional wired infrastructure-based, and in two wireless ad hoc network emulation scenarios. The measurementsindicate that our solution can push the upper limit of emulation scenario sizes by a factor of 10–28. Given our emulation testbed consisting of 64 computers, this translates to possible scenario sizes of up to 1792 nodes. In addition to the evaluation of our virtualization approach, we discuss key concepts for controlling comprehensive emulation scenarios to support scalability of our system as awhole.

Langue: Anglais