Performance Of Bundle Protocol For Deep-space Communication In Presence Of Link Disruptions

Delay/disruption tolerant networking(DTN) is a kind of network architecture deployed in deep-space environment to handle lengthy link disruptions, an extremely long propagation delay, and asymmetric channel rates. DTN communications rely heavily on Bundle protocol(BP) which uses the well-known approach of store-and-forward with optional custody transfer for which a node agrees to hold a file in memory(or storage) until its successful reception is acknowledged by the next node.However, little work has been seen in performance modeling of BP for reliable file transfer in deep-space communication with lengthy link disruptions. In this paper, we present performance evaluation of the BP running above unreliable UDPCL/UDP protocols over a relay-based deep-space communication system characterized by lengthy link disruptions. An analytical model is built to estimate the total file delivery time of BP for file transmission. A model is also built to characterize the dynamics of memory occupancy and release. The research adopts ION software developed by Jet Propulsion Lab(JPL) and BP/UDPCL/UDP stacks running on SCANT simulation platform. The built models are validated by running file transfer experiments. And the experimental results show that BP/UDPCL/UDP stacks can combat link disruptions in deep-space communication and guarantee file delivery time and dynamic throughput to some extent. In addition, the smaller bundle will result in higher goodput and quicker memory release.