From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wr1-x435.google.com (mail-wr1-x435.google.com [IPv6:2a00:1450:4864:20::435]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by lists.bufferbloat.net (Postfix) with ESMTPS id BC3903B2A4 for ; Mon, 13 Dec 2021 04:28:22 -0500 (EST) Received: by mail-wr1-x435.google.com with SMTP id a9so25843792wrr.8 for ; Mon, 13 Dec 2021 01:28:22 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=u1DLuMw926gO4SpbNZ7dicmmLS3O7nuberb4zX1pV78=; b=ihFDfKWR6B0tF4zqX6dAM+aJJgcKYJxIabesZSaFPVTri/HNbNBerfFM8F7QkSuRYW KCVWZX2S0/1ZhpGkwtc5u48bzJqhrvsBMY8DlOw/n905Q3PM7W5czFsVoWhUuQTCYrr2 4GhrAqVHUZnuuB5ABwZxK5yTnMDK0wDzVNzvJHoV3m53acNTGM7CfOxJos4/N+C+kVws 7WADk0qyfrdYWLdDxG2ObQwZDqcqTkVWq/NKU5978NVGavLtj8tS6dGK9yPG2Sz+eaNi VNN5EHucFNe+miK2sNBDYgt1WXMhGO7s5Y+cU0EWeK91SvYIMowBomxFrz8iO1Xg25T1 VwnQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=u1DLuMw926gO4SpbNZ7dicmmLS3O7nuberb4zX1pV78=; b=rBEYrfn5eqdBFfQ2r1dr1hYkcH0VLIlxnmSF0Hml4rkM93c8cSQrFLVDO8NYyxqaGN hmSj7vhjh+zWAnDeic2TWk3ZJGan8yIbH9As97DQ0UsZZXYxAqYrd1U27uEDtP1BHZdr uVfLsh1H7aB0rJz46P+TwhGZX6Aw9Fzlk2sJNSkdMKruWGqJHaDR1gDKQ9l/1c0dhu3d g6qsJ8nbWcEyrn/Lpyjm9S7KM1dTfSbYawfCqEqKLezFT8iyr4dtHXYXATm/N2fr4Ekj iGsqNl8bdIW4PoE/jdqW1RZ5SKnXJaqvnbtg85bdmh0ffRP36UojzmEbBZWKah1RJ3By m1Mw== X-Gm-Message-State: AOAM5311Z7Krr3g4d2crgKJNE1arjXj1KS8To2rzUuhZQieaQhFX2a4Q CPFTpC95wrfA0Z6oHAEGUVqqoptuWYBlfrT9nFPgMXHsv9s= X-Google-Smtp-Source: ABdhPJweCDDpE12RFo5ajXc0PRwLJ43a7RXEU+sIcgzEtnb7NPLsOFWbv7y6civbrF8Qyo+O/pTRZV4q5vKDwWLri9o= X-Received: by 2002:a5d:514a:: with SMTP id u10mr30851915wrt.321.1639387701091; Mon, 13 Dec 2021 01:28:21 -0800 (PST) MIME-Version: 1.0 References: In-Reply-To: From: Vint Cerf Date: Mon, 13 Dec 2021 04:28:08 -0500 Message-ID: To: Dave Taht Cc: starlink@lists.bufferbloat.net Content-Type: multipart/alternative; boundary="00000000000092f00605d303b19e" Subject: Re: [Starlink] some details on the DTN, bundle protocol, and a capacity question X-BeenThere: starlink@lists.bufferbloat.net X-Mailman-Version: 2.1.20 Precedence: list List-Id: "Starlink has bufferbloat. Bad." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 13 Dec 2021 09:28:22 -0000 --00000000000092f00605d303b19e Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable we have the most experience with the ION version of BPv7 v On Sun, Dec 12, 2021 at 7:06 PM Dave Taht wrote: > On Sat, Dec 11, 2021 at 7:15 PM Vint Cerf wrote: > > > > 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 whic= h > we might derive measurements to compare with actual data and modeled > (queueing theoretic) data. > > I am just going to ignore the way this thread went for now. What I was > mostly asking was what version of dtn was the most promising for an > embedded (e.g. cerowrt II) implementation? > > https://dtn7.github.io/ looks very promising, especially the rust > bits. Rust lets me sleep better and we are moving some support for it > into openwrt's next release. > > https://github.com/morgenroth/ibrdtn is undermaintained but was > already ported to openwrt, and is lighter weight. There's another one > targetted at microcontrollers ( https://upcn.eu/ ), but not the FRAM > one we used on a previous space-related project... really liked those > FRAMs.... > > As for the simulator side, what/where are the requirements? I confess > to wanting to feed forward the asterank, or celestia, or nasa's new > https://eyes.nasa.gov/apps/asteroids/#/asteroids into it another 10 > years and plunk 28k nodes into it.... > > > > > > > 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=3Dhttps%3A%2F%2Fwww.icei.org > >> > >> Dave T=C3=A4ht 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 <(703)%20448-0965> > > > > until further notice > > > > > > > > > -- > I tried to build a better future, a few times: > https://wayforward.archive.org/?site=3Dhttps%3A%2F%2Fwww.icei.org > > Dave T=C3=A4ht CEO, TekLibre, LLC > --=20 Please send any postal/overnight deliveries to: Vint Cerf 1435 Woodhurst Blvd McLean, VA 22102 703-448-0965 until further notice --00000000000092f00605d303b19e Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
we have the most experience with the ION version of BPv7
v


On Sun, Dec 12, 2021 at 7:06 PM Dav= e Taht <dave.taht@gmail.com&g= t; wrote:
On Sat= , Dec 11, 2021 at 7:15 PM Vint Cerf <vint@google.com> wrote:
>
> 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 (queue= ing theoretic) data.

I am just going to ignore the way this thread went for now. What I was
mostly asking was what version of dtn was the most promising for an
embedded (e.g. cerowrt=C2=A0 II) implementation?

ht= tps://dtn7.github.io/ looks very promising, especially the rust
bits. Rust lets me sleep better and we are moving some support for it
into openwrt's next release.

=C2=A0https://github.com/morgenroth/ibrdtn=C2=A0 is undermai= ntained but was
already ported to openwrt, and is lighter weight. There's another one targetted at microcontrollers (=C2=A0 https://upcn.eu/ ), but not the FRAM
one we used on a previous space-related project... really liked those
FRAMs....

As for the simulator side, what/where are the requirements? I confess
to wanting to feed forward the asterank, or celestia, or nasa's new
https://eyes.nasa.gov/apps/asteroids/#/asteroids= into it another 10
years and plunk 28k nodes into it....





> v
>
>
> On Sat, Dec 11, 2021 at 9:58 PM Dave Taht <dave.taht@gmail.com> wrote:
>>
>> A good deep dive into DTN with vint cerf is here:
>> https://= www.datacenterdynamics.com/en/analysis/vint-cerfs-interplanetary-ambitions/=
>>
>>=C2=A0 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 st= orage
>> each node needs to the speed of the network?"
>>
>> VC: That's such a good question. So guess what, I have the sam= e
>> 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 netwo= rk,
>> given if I know where the nodes are, and I know what the physics a= re.
>> 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 MI= T on
>> this topic, not in aid of the interplanetary network, but more gen= eral
>> question on store and forward networking.
>>
>> And so he did some fantastic work, he broke the back of the proble= m
>> with what was called the independence principle. But he left MIT a= nd
>> came to UCLA in the '60s, he was on my thesis committee. And h= e's
>> still very, very active. He's 87, still blasting on.
>>
>> So I sent him a note saying, look, here's the problem. I'v= e 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 den= se
>> 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 th= e 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=3Dhttps%3A%2F%2Fwww.icei.org
>>
>> Dave T=C3=A4ht CEO, TekLibre, LLC
>> _______________________________________________
>> Starlink mailing list
>> Starlink@lists.bufferbloat.net
>> https://lists.bufferbloat.net/listinfo/starl= ink
>
>
>
> --
> Please send any postal/overnight deliveries to:
> Vint Cerf
> 1435 Woodhurst Blvd
> McLean, VA 22102
> 703-448-0965
>
> until further notice
>
>
>


--
I tried to build a better future, a few times:
https://wayforward.archive.org/?sit= e=3Dhttps%3A%2F%2Fwww.icei.org

Dave T=C3=A4ht CEO, TekLibre, LLC


--
Please send any postal/ove= rnight deliveries to:
Vint Cerf
1435 Woodhurst Blvd=C2= =A0
McLean, VA 22102
703-448-0965

<= div>until further notice



=
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