Network emulation testbed for DTN applications and protocols

Wireless devices are widely used today to access the Internet, despite the intermittent network connectivity they often provide, especially in mobile circumstances. The paradigm of Delay/Disruption Tolerant Networks (DTN) can be applied in such cases to improve the user experience. In this paper we present a network testbed for DTN applications and protocols that we developed based on the generic-purpose wireless network emulation testbed named QOMB. Our testbed is intended for quantitative performance assessments of DTN application and protocol implementations in realistic scenarios. We illustrate the practicality of our emulation testbed through a series of experiments with the DTN2 and IBR-DTN implementations, focusing on mobility in urban environments. The scalability issues that we have identified for DTN2 emphasize the need to perform large-scale repeatable evaluations of DTN applications and protocols for functionality validation and performance optimization.