Virtual Integrated TCP Testbed (VITT)

Research on TCP performance relies either on simulation programs, which run on a single machine, or on the use of real testbeds, where different machines represent different network nodes and data exchange is made through physical network interfaces. This paper proposes a different solution, with the aim of taking the best of both the cited alternative options. The idea is to exploit the most advanced virtualization technologies to integrate the different devices of a real testbed in a single GNU/Linux physical machine. The Virtual Integrated TCP Testbed (VITT) presented in this paper is the practical realization of this concept. Several virtual machines, fully configurable from the host system, are connected through an emulated network, implemented by means of the software tools provided by the Virtual Distributed Ethernet (VDE) project. A simple web interface allows the user to configure the network layout, set the TCP parameters, launch the experiments and gather the results. VITT is built on the experience achieved by the authors in the design and use of a real distributed testbed (TATPA), from which VITT derives some software components. TATPA results proved essential to assess the present limits of the virtualization approach, i.e. the accuracy of results vs. network complexity.