#topographie/colline [IPNSIG Academy Events](https://ipnsig.org/ipnsig-academy-events/) # [DTN Projects Work](https://isoc.live/15587/) #à/visionner # [DTN Overview](https://isoc.live/15464/) TCP/IP flow control is not adapted to space communication. Since it takes a long while to send message (Earth-Mars communication is between 3.5 to 20 minutes, twice if you want an answer), you cannot expect the receiver to tell you he can't receive your message anymore. It would lead to a lot of wasted data, dropped for lack of buffer. DNS (Domain Name System) doesn't work if it takes so long to initiate communication that one party has the time to change domain. With the Bundle Protocol, you need a reliability layer on top of it. (IP and Bundle Protocol are very similar: they are unreliable.) BP naming protocol is flat (compared to the hierarchical of IP). You can't rely on a lot of handshakes (none?) because 1. the system is unreliable 2. the message propagation is too slow Authentification and security built into Bundle Protocol. #à/rechercher: - CCSDS file delivery protocol - Border Gateway Protocol was for accommodating inter domain communication. Bundle protocol allows a relay to receive data from a source, keep until it arrives at the right point in space to send to the next hop. (IP assumes continuous connection.) OMG THE ISS IS USING IT (AND IT IS UPDATED REGULARLY ON IT!!) (for personal comm and experimentations, of course). One protocol has been called Licklider Transmission Protocol (LTP) DTN works in Earth area with low connectivity! ## Current implementations available on GitHub - ION (from NASA) - IBR-DTN (from the Technical University of Braunschweig) # [100+ years vision](https://isoc.live/15417/) ![[Yosuke Kaneko 2100 SSI.png]] ![[Yosuke Kaneko Characteristics of ISS.png]] CCSDS: Consultative Committee on Space Data Systems IETF: Internet Engineering Task Force