[ih] How Plato Influenced the Internet

[Bob Purvy]

On type of service and guaranteed bandwidth: I'm so glad you didn't. It let
me make money at Packeteer later!

On Wed, Aug 25, 2021, 12:13 PM Jack Haverty via Internet-history <
internet-history at elists.isoc.org> wrote:

> Hi Steve,
>
> I wasn't worrying about efficiency; I just wanted to see if I could
> figure out how to make some ternary logic.   IIRC, the class was on
> digital design, and the lab assignment was basically "build something
> digital, other than the examples we used in the lectures".   Rather than
> building boring flipflops and gates, maybe an adder, I decided to try to
> create ternary logic.   After all, they said "digital", so it didn't
> have to be binary.   I always tended to think outside the box.
>
> Your math is probably correct, but it's only a small part of making a
> design choice.   At about the same time of that lab course, I had a
> student job using a PDP-8 to gather and analyze data from experiments
> being done at the "Instrumentation Lab".   They were designing,
> building, testing, and deploying inertial navigation units that were use
> in a lot of places, including the Apollo spacecraft.  So I actually got
> to work with real "rocket scientists".  I learned as much from those
> engineers and scientists as I did from the classes.
>
> One thing I learned was that much of the mathematical toolbox from the
> courses wasn't terribly useful.  For example, there were lots of tools
> and techniques for minimizing Boolean logic.   But reams of data had
> shown that the critical issue for reliability (it's hard to fix things
> in space) was the mechanical connections involved, e.g., how many pins
> on a PC board and corresponding socket were needed in the system
> design.   More logic circuitry was OK if it meant fewer pins were
> needed.   None of the tools and techniques taught in courses even
> mentioned the issue of pins or other such design questions, such as heat
> dissipation.
>
> So, it's possible that some kind of non-binary logic might have required
> fewer pins and resulted in more reliable hardware.  Or not.  The choice
> made early on meant we'd never pursue any other path.
>
> Getting back to Plato and the Internet, I can confirm that I never saw
> or even heard of Plato during the 60s/70s/80s.  So it probably didn't
> influence me, at least not directly.
>
> However, I was surprised to just read how Plato was focussed on latency
> as a key driver of the users' experience.   I ran into that same issue
> at Licklider's MIT lab, when we were trying to bring up MazeWars on our
> newfangled Imlacs that were used as terminals on the PDP10.   I spent a
> bit of time tweaking the RS232 TTY interfaces to get the line speed up
> around 100 kb/sec (typical max was 9.6 in those days), and that made the
> Maze game popular.   When you "shot" an opponent they died as they
> should.  With higher latency, they'd often inexplicably get away.
>
> We tried to convince BBN to upgrade TIPs to run faster, but were
> rebuffed.  The TIPs supported the "maximum reasonable speed" of 9.6.
> Nothing faster was needed.
>
> Later on, circa 1978 while we were rearchitecting TCP to split out TCP
> and IP, and introduce UDP, I remembered my experience with latency, and
> pushed for inclusion of "Type Of Service" so that the underlying IP
> transport might someday be able to offer both low-latency and
> high-throughput services to meet different users' needs.   And maybe a
> "guaranteed bandwidth" service to better mimic old physical circuits.
>
> Low latency was also important for things like conversational voice, so
> the "voice guys" at places like ISI and Lincoln were also interested in
> having such a capability in the Internet.   I don't recall that "Plato
> guys" were involved, but I bet they would have been proponents as well.
>
> Sadly, although those experiences certainly "influenced the Internet" to
> the extent that various header fields and rudimentary mechanisms were
> included in the emerging TCP that we still have today, there apparently
> wasn't enough pressure and interest to cause low-latency service to
> actually get implemented.   At least as far as I can tell....
>
> I can't see "inside" the Internet now, just as a user today.   But
> simply watching the now constant stream of live interviews on TV, and
> the pixelization, breaking audio, and such artifacts, makes me conclude
> that low-latency service isn't there yet, after 40 years of evolution.
>
> I suspect part of the cause was also the hardware availability, or lack
> thereof.  Like Plato, Imlacs were not common in "the network community"
> and neither were voice-capable terminals.  So unless you had one of
> those, you didn't understand why things like low-latency were needed.
> So the "rough consensus" never emerged for such mechanisms.
>
> Plato, and Maze, and Conversational Voice, and no doubt others,
> influenced the Internet.   But not enough to drive the associated
> functionality all the way to deployment.
>
> Sometimes history is about what didn't happen.   And why.
>
> /Jack
>
>
>
>
> On 8/23/21 7:47 PM, Steve Crocker wrote:
> > Jack,
> >
> > A classic analysis of bits vs trits says trits are slightly more
> > efficient.  The analysis is based on assuming that it takes b parts to
> > represent a digit in base b.  Two parts for a bit, three parts for a
> > trit, four parts for a quit(?!).  The information content of k digits
> > in base b is b^k.  The "cost" is b*k.  The optimal base is e
> > (2.71828...). Bases 2 and 4 are equal.  (The information content of 2k
> > bits is 2^(2k).  The information content of k quits is 4^k.  The costs
> > are the same, i.e. 4k.)
> >
> > Trinary is better but not by much.  Using six parts, you can make
> > three bits or two trits.  The information content of three bits is 8.
> > The information content of two trits is 9.
> >
> > A different consideration of using trinary vs binary is the
> > representation of integers.  As we all know from hard experience, twos
> > complement representation of signed integers gives you an asymmetry
> > with one more negative number than positive number.  Switch to ones
> > complement and you wind up with two representations of zero.  Trinary
> > gives you a naturally symmetric representation of signed integers.
> >
> > I think that's the end of the advantages of trinary over binary.  But
> > I'm VERY impressed you took the time and effort to actually build such
> > circuits.  Bravo!
> >
> > Steve
> >
> >
> > On Mon, Aug 23, 2021 at 10:29 PM Jack Haverty via Internet-history
> > <internet-history at elists.isoc.org
> > <mailto:internet-history at elists.isoc.org>> wrote:
> >
> >     Back in the 60s, a lot of computer technology was not yet cast in
> >     concrete.  There were lots of choices.  But then someone pursues one
> >     choice, and if it works reasonably well, others follow the same path.
> >     It doesn't take very long for the "installed base" to become so large
> >     that it's unlikely that some other initial choice could easily take
> >     over.    Think about how long it's taken, so far, for IPV6 to
> >     supplant IPV4.
> >
> >     Sometime around 1968, as a learning experience in some lab course at
> >     MIT, I decided to make some non-binary logic.   At the time, analog
> >     computers were still around, and digital computers hadn't yet agreed
> >     even on how many bits were in a byte, or how to encode characters, or
> >     what order bits should be in a computer memory word.   But bits were
> >     pretty well established.
> >
> >     I figured there must be other choices.   So I made some ternary
> >     logic.
> >     Unlike binary, which dealt with 1s and 0s, I used +1, 0, and -1 as
> >     the
> >     three possible states.  Electronically it translated into positive,
> >     negative, or no current.   Using transistors and such components,
> >     I made
> >     some basic logic "gates" that operated using three states instead of
> >     two.  Was that a good idea?   Probably not, but it was a good way to
> >     learn about circuits.    Instead of bits (binary digits), how about
> >     manipulating trits (trinary digits)? There's nothing magic about
> >     1s and 0s.
> >
> >     Shortly thereafter, binary took over as circuitry went into
> >     integrated
> >     circuits and a whole industry came in to being around binary
> >     computers.   If some other kind of approach, ternary, quaternary, or
> >     whatever is better than binary, we'll probably never know.   I
> >     suspect
> >     something might happen soon with qubits though to challenge bits
> >     supremacy..
> >
> >     There are lots of ways to do things, and the one that "wins" might
> >     not
> >     have been the best choice.
> >
> >     Imagine how networking and computing might have evolved with trits
> >     instead of bits....
> >
> >     /Jack
> >
> >
> >     On 8/23/21 12:15 PM, John Day via Internet-history wrote:
> >     > Agreed.  There are only so many ways to do something. ;-)
> >     >
> >     >> On Aug 23, 2021, at 14:46, Craig Partridge <craig at tereschau.net
> >     <mailto:craig at tereschau.net>> wrote:
> >     >>
> >     >>
> >     >>
> >     >> On Mon, Aug 23, 2021 at 8:12 AM John Day via Internet-history
> >     <internet-history at elists.isoc.org
> >     <mailto:internet-history at elists.isoc.org>
> >     <mailto:internet-history at elists.isoc.org
> >     <mailto:internet-history at elists.isoc.org>>> wrote:
> >     >> It is not uncommon in the history of technology (it has been
> >     observed back several centuries) that it isn’t so much direct
> >     transfer of technology but more someone brings back a story along
> >     the lines of, ‘I saw this thing that did thus and so and kind of
> >     looks like t.’ Which gives someone the idea, that if it exists,
> >     then how it must work like this.’ It isn’t quite independent
> >     invention, but it isn’t quite direct influence either.
> >     >>
> >     >>
> >     >>
> >     >> Related comment -- from my various interactions with historians
> >     about technology history.  If the available technology is limited
> >     (as it was in the 1950s/60s/70s and early 1980s in many
> >     dimensions) then your solutions to certain problems are going to
> >     look rather similar.  That doesn't meant that two similar
> >     solutions influenced each other... The trick in writing tech
> >     history is figuring out where there was a choice space and where
> >     there wasn't (much of) one.
> >     >>
> >     >> Craig
> >     >>
> >     >>
> >     >> --
> >     >> *****
> >     >> Craig Partridge's email account for professional society
> >     activities and mailing lists.
> >
> >
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> >
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