Delay/Disruption Tolerant Networking (DTN) is designed for a severe
environment where communication quality is not guaranteed. It works as
an overlay network associated with Bundle Protocol (BP) and some
convergence layer protocols like Licklider Transmission Protocol
(LTP). DTN is suitable for satellite networks. Because communication
delay is long and peer-to-peer communication is not guaranteed in
satellite networks. We implement SDN to solve the problems of
controllable, manageable, and flexible in satellite networks. In this
document, we propose a framework of Software Defined DTN-based
satellite networks, using Bundle tunnel and protocol translation
gateway.