I haven't pushed to much further until we get some real data from running implementations. I also hope we can develop a simulator from which we might derive measurements to compare with actual data and modeled (queueing theoretic) data. v On Sat, Dec 11, 2021 at 9:58 PM Dave Taht wrote: > A good deep dive into DTN with vint cerf is here: > > https://www.datacenterdynamics.com/en/analysis/vint-cerfs-interplanetary-ambitions/ > > I went looking for existing source code for it, some here: > https://projet.liris.cnrs.fr/riot/dtn_implementations_survey.html > > From the interview... > > Q: "So for store and forward to work, what is the level of storage > each node needs to the speed of the network?" > > VC: That's such a good question. So guess what, I have the same > question. And I said, 'Okay, where do I go to get an answer to that?' > And that is the capacity question: What capacity of this DTN network, > given if I know where the nodes are, and I know what the physics are. > And I know what the data rates could be. I have a traffic matrix. Do I > have a network which is capable of supporting the demand? > > That's the formulation of the question you're asking. So I went to the > best possible source for this question, Leonard Kleinrock at UCLA. He > is the father of the use of queueing theory to analyze store and > forward networks way back in 1961/62, doing his dissertation at MIT on > this topic, not in aid of the interplanetary network, but more general > question on store and forward networking. > > And so he did some fantastic work, he broke the back of the problem > with what was called the independence principle. But he left MIT and > came to UCLA in the '60s, he was on my thesis committee. And he's > still very, very active. He's 87, still blasting on. > > So I sent him a note saying, look, here's the problem. I've got this > collection of notes, and I've got a traffic matrix, and I have this > DTN environment, how do I calculate the capacity of the system so I > know, I'm not gonna overwhelm it. > > And, you know, I figured it would take him a while and maybe find a > graduate student. So *two days later*, I get back two pages of dense > math saying, okay, here's how you formulate this problem. Now, I > didn't get all of the answer. I still don't have all of the answer. > But I know I have one of the best minds in the business looking at the > problem." > > That was back in august of this year, made any progress? > > -- > I tried to build a better future, a few times: > https://wayforward.archive.org/?site=https%3A%2F%2Fwww.icei.org > > Dave Täht CEO, TekLibre, LLC > _______________________________________________ > Starlink mailing list > Starlink@lists.bufferbloat.net > https://lists.bufferbloat.net/listinfo/starlink > -- Please send any postal/overnight deliveries to: Vint Cerf 1435 Woodhurst Blvd McLean, VA 22102 703-448-0965 until further notice