Towards realism in DTN performance evaluation using virtualization

There is a lack of reliable tools for evaluating the performance of Delay Tolerant Networks (DTN). Frequently, the researchers use small-scale real networks or one of the few available DTN simulators. This work presents an alternative approach for conducting performance evaluation studies of DTN, following a recent movement of the scientific community with respect to the use of hybrid environments in order to achieve realism in the studies. We propose, implement and validate the Virtualized DTN Testbed (VDT) as a means to construct a virtualized testbed completely in software that takes into account a real instance of the operating system and applications that run inside the mobile nodes, as well as a robust model of the wireless channel. The results show that VDT can accurately reproduce both the mobility of nodes, and the contact opportunities obtained in experiments of a real testbed. Moreover, we identified some implementation problems in the real experiments, that after some fixing strategies allowed us to identify the occurrence of several contacts not registered previously.