This paper describes a simulation environment to easily create complex Delay Tolerant Network (DTN) scenarios using Virtual Network User Mode Linux (VNUML), a network virtualization environment based in User Mode Linux virtual machines running the DTN reference implementation. The simulation environment allows us to explore the applicability and behavior of the DTN architecture in real isolated-areas scenarios in developing countries. Furthermore, new developments built in the reference implementation (dynamic routing, multicast, anycast) can be easily debugged and analyzed.