Mars to Earth Data Downloading: A Directory Synchronization Approach

This paper aims to present a possible alternative to direct file transfer in “challenged networks”, by using DTNbox, a recent application for peer-to-peer directory synchronization between DTN nodes. This application uses the Bundle Protocol (BP) to tackle long delays and link intermittency typical of challenged networks. The directory synchronization approach proposed in the paper consists of delegating the transmission of bulk data files to DTNbox, instead of modifying source applications to interface with the API of a specific BP implementation, or making use of custom scripts for file transfers. The validity of the proposed approach is investigated in the paper by considering a Mars to Earth interplanetary environment. Experiments are carried out by means of Virtual Machines running ION, the NASA-JPL implementation of DTN protocols. The results show that the directory synchronization approach is a valid alternative to direct transfer in interplanetary scenarios such as that considered in the paper.