Performance evaluation of DTN implementations on a large-scale network emulation testbed

In this paper we present a series of experiments that evaluate the performance of two DTN implementations, DTN2 and IBR-DTN, in urban mobility scenarios. The experiments were carried out on the wireless network emulation testbed named QOMB, which was extended to support such DTN evaluations. Our quantitative assessment verified the basic behavior of the DTN implementations, but also identified scalability issues for DTN2 in scenarios with as few as 26 nodes. These results emphasize the need for more extensive large-scale experiments with DTN applications and protocols for comprehensive evaluations in view of functionality validation and performance optimization. This can be readily achieved through the use of emulation testbeds such as the one that we have developed.