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This is the first of a number of blog entries designed to help newbies come up to speed on Delay & Disruption Tolerant Networking. If you find an online article you think others would be interested in, or if there is a topic you would like to see covered in future blogs, drop a note to newsworthy@ipnsig.org.


What if I don’t know anything about IPN?

 Many members of IPNSIG may be familiar with the technologies behind the traditional Internet, but be completely new to the domain of Interplanetary Networking and DTN (Delay & Disruption Tolerant Networking). While there are hundreds of technical articles available about different aspects of DTN, these articles typically assume previous knowledge of the technical foundations of the protocols and the problems they are attempting to solve. One can always turn to RFC’s… but they also assume the reader is “in” on the technical context.


What is a newbie to do?

There are a number of terse introductory videos and online documents available to help newbies come up to speed, and some on them are available on the ipnsig.org website.


Here’s a couple:


A short TED Talk by Vint Cerf explaining the very basic challenges IPN presents and DTN’s approach to addressing them: http://tedxtalks.ted.com/video/TEDxMidAtlantic-2011-Vint-Cerf


A terse technical introduction to DTN, covering most major topics. Many thanks to Forrest Warthman of Warthman Associates) for authoring this latest version (and Scott Burleigh of NASA/JPL for technical consultation and review). https://drive.google.com/file/d/1kLGx6nGSTd5xrs1oE0JeTsIQYwjrYt6n/view?usp=drive_link


However, if you really want to understand Interplanetary Networking and DTN, we’d suggest you investigate a couple of recently published books that provide both a solid overview of the history, architecture and technologies involved in DTN:


Delay and Disruption Tolerant Networks: Interplanetary and Earth-Bound — Architecture, Protocols, and Applications CRC Press – Aloizio Pereira da Silva (Editor), Scott Burleigh (Editor), Katia Obraczka (Editor) – 2018


Delay-Tolerant Satellite Networks (Space Technology and Applications) Artech House – Juan A. Fraire (Author), Jorge M. Finochietto (Author), Scott C. Burleigh (Author) – 2017


While books like these represent an investment in time and money (there is a Kindle edition available at deep discount for Delay and Disruption Tolerant Networks: Interplanetary and Earth-Bound — Architecture, Protocols, and Applications), there is much to be gained by plowing one’s way through them. Both contain excellent introductory content that lays a good foundation for the reader in understanding later technical topics.


As the title indicates, Delay-Tolerant Satellite Networks (Space Technology and Applications) focuses almost exclusively on DTN in space data communications. The more limited scope allows the authors to explain not only DTN, but also the existing and planned space communications infrastructure upon which it operates.


Delay and Disruption Tolerant Networks: Interplanetary and Earth-Bound — Architecture, Protocols, and Applications expands the arena for DTN to include the many, many terrestrial applications for addressing constrained network environments. These run the gamut from enabling email delivery for reindeer herders in the Arctic Circle to providing basic Internet services to villagers in rural Africa. There’s an entire chapter devoted to DTN’s usefulness in the burgeoning world of the Internet of Things (IoT).


There is also the first book-length treatment of DTN from back in 2006:

Delay- and Disruption-Tolerant Networking - Artech House Publishers – Stephen Farrell, Vinny Cahill – 2006


Stephen Farrell was the co-chair of the DTN Research Group. This book is most useful for an understanding of the history of DTN development and why it is so necessary for both interplanetary and constrained terrestrial networking environments.


Still daunted?

We are all newbies at some point in understanding any topic in depth. It can be overwhelming. We encourage you to take advantage of some of the resources highlighted in this blog posting. We’ll be focusing on online video resources introducing you to the world of DTN in our next blog entry.


This blog is a product of the usual suspects: Scott Burleigh (NASA/JPL); Jay Wyatt (NASA/JPL); Keith Scott (Mitre Corp./CCSDS) and Mike Snell (IPNSIG)

Some new content has recently become available that I believe IPNSIG members would find interesting.


Leigh Torgerson, IPNSIG member and Space Communications Networking Architect from JPL/NASA, has posted some useful animations explaining Delay and Disruption Tolerant Networking concepts. It’s available for viewing at: https://www.youtube.com/user/spacenetworking


Leigh also recently made a presentation that was even more recently released for publication. It’s available here: 332-Section-DTN-Seminar-2019-for-Public-Release–final

The presentation provides fairly detailed historical background, an explanation of why Internet protocols do not work in space, and a picture of where DTN is going in the near future.


Enjoy!


Welcome to the InterPlanetary Networking Blog!


We intend to make this a weekly publication of interest to everyone interested in InterPlanetary Networking (IPN), Delay & Disruption Tolerant Networking (DTN), and computer networking in general.

Since this is the inaugural blog entry, we thought it would be useful to back up a bit and answer some basic questions:


What is IPN?

It is a solution to the constrained network environment present in space data communications and, more generally, in the emerging Internet of Things.


TCP/IP, the core technology [BSC(1] running today’s Internet, assumes essentially instantaneous, continuous end-to-end connectivity, and fails when it encounters delay or disruption of any significant length (about 4 seconds).


However, delays and disruptions are inherent in data communications at interplanetary distances, with the shortest Round Trip Time (RTT) for a radio signal to travel to Mars and back being about 7 minutes. Other factors contribute to the network constraints existing in interplanetary communications, but delay is the most significant factor making existing Internet protocols impractical for use.


Enter DTN:

Adrian Hooke (Sr. Technical Director with the Jet Propulsion Laboratory, NASA) meets Vint Cerf (co-author of the TCP/IP protocols and one of “Fathers of the Internet”) in the late 1990’s. They discover they both want to provide the same kind of network communications automation in space networking that works so well on the Internet.


Vint Cerf gets to work. A terse history follows:

  • DARPA funds work at JPL.

  • Core experimental “delay-tolerant networking” protocols developed by JPL, MITRE, Sparta researchers.

  • ION implementation of DTN developed at JPL for use by NASA.

  • DTNRG established to mature the protocols.

  • ION demonstrated on the EPOXI spacecraft in deep space.

  • ION deployed for all science payload communications on ISS.


Where is IPN today?

  • IETF DTN Working Group formed to establish DTN protocols as Internet standards.

  • Consultative Committee for Space Data Systems (CCSDS—a global standards setting organization for civilian space flight) standards adoption well underway.

  • Security Protocols maturing (including Public Key Infrastructure—PKI).

  • Dr. Scott Pace (White House Space Policy Director) challenges NASA to use DTN for all space communications (see https://www.youtube.com/watch?v=InMP-OI1thw&index=9&list=PL4buVHalBRoPpFRFlpYVnXHLwWNwFmpmt&t=0s for Dr. Pace’s presentation at our 2015 IPN Speakers Conference).

  • NASA integrating DTN into ground networks and future spacecraft.


IPN’s bright future

  • Increasing standardization amongst civilian space agencies.

  • Increasing international research into DTN for constrained terrestrial as well as space networking environments.

  • Coming adoption as internet standards.


What’s next for the blog?

Each week, we will post news about the exciting world of IPN, or summaries of academic research, or links to IPN in the mainstream media. We’ll also be announcing upcoming IPNSIG events and activities. We hope you enjoy the blog.

This blog is a product of the usual suspects: Scott Burleigh (NASA/JPL); Jay Wyatt (NASA/JPL); Keith Scott (Mitre Corp./CCSDS) and Mike Snell (IPNSIG)


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