[Starlink] some details on the DTN, bundle protocol, and a capacity question

[Dave Taht]

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