[ih] Recently restored and a small ARPANET was run using simulated IMP hardware. (was: TTL [was Exterior Gateway Protocol])

[the keyboard of geoff goodfellow]

Jack, you're a Most Eloquent purveyor of history and that WHY explain is
exactly what yours truly was hoping for... Thank You for the elucidation! :D

along the lines vis-a-vis:

So, that's a bit about the "Why", for history to ponder.  The experience
got me wondering about the "patent history" of The Internet.  Clearly there
was a lot of innovation in those days.  My recollection is that very little
was patented, even if only to make sure no one else could.  Maybe someone
will document the patent-related aspects of Internet History someday.

please excuse/pardon this immodesty: yours truly had a kinda similar
"lawyered" experience with respect to WHO was the purported
"inventor"/originator of wireless email in a patent litigation case and the
"challenge" of finding/presenting any extant legally submissive
"artifactual proof" to that effect -- for which John Markoff at the New
York Times wrote about in this 2006 article:

In Silicon Valley, a Man Without a Patent
https://www.nytimes.com/2006/04/16/business/technology/in-silicon-valley-a-man-without-a-patent.html

for which some links of "proof" exist -- for some stuff mentioned in the
above NYT article -- on my website https://iconia.com/ under "wireless
email" (in case any historians are duly interested)...

geoff

On Sun, Sep 6, 2020 at 8:24 AM Jack Haverty <jack at 3kitty.org> wrote:

> Geoff,
>
> Dave's IEEE paper does an excellent job of the Who/What/When/Where.  He's
> right that it was about 7 years ago.   Time flies... but I guess it's still
> "recent" when viewed as part of Internet History.
>
> For the curious, I can add a bit more about the Why.
>
> Sometime in 2013, I got an email out of the blue from Charlie Neuhauser,
> someone I didn't recognize or remember at all, asking if I was the "Jack
> Haverty" who authored IEN 158 - documenting the XNET protocol in 1980.
> Figuring that the statute of limitations must have expired after 30+ years,
> I cautiously said yes.  Over the next few days, he hooked me up with the
> lawyers who were involved in a patent dispute - one that had been going on
> for several decades by then.  In fact, the patent involved had been issued,
> ran its 17 year lifetime, and expired, but there was still litigation in
> process about whether or not the patent was valid, and 17 years of
> violations were alleged cause for compensation in the many millions.   For
> the next few years I was involved in the battles, working with the lawyers
> scattered all over the country.  I never met any of them.  All our work was
> done by email and telephone.   No Zoom then or we probably would have used
> it.
>
> The core issue in the patent battle concerned "downloading instructions",
> mechanisms such as would be involved in patching or issuing new software
> releases to remote equipment.   XNET seemed to them to possibly have
> something to do with that, hence the interest.  The goal was to find hard
> evidence that such procedures were being done by 1980, which would prove
> that prior art existed.  Hard evidence literally means "hard" - opinions
> help, but physical equipment and running code is much more impressive in a
> courtroom.
>
> They hadn't found any XNET artifacts, and I couldn't point them to any
> surviving implementations.   But I pointed out that my XNET document simply
> captured the technology that we "stole" from the ARPANET IMP experience,
> and that the IMPs routinely "downloaded code" from their neighbors and the
> NOC all during the life of the ARPANET.
>
> Since the IMPs had existed since the early 70s, that really sparked their
> interest, and a search (worldwide) ensued to find old IMPs, in the hope
> that just maybe one of them still had the IMP software in its magnetic-core
> memory.  A few IMPs were located, but none were functional.  The one in the
> museum at UCLA seemed promising, but the owners were reluctant to even hook
> it up to power after sitting idle for so many years, expecting it might go
> up in smoke.
>
> Then I learned from the BBN alumni mailing list that an ancient IMP
> listing had been found in a basement.   The story from that point is pretty
> well described in Dave's paper.
>
> Personally, it was an interesting experience.  I worked extensively with
> one lawyer in San Diego.  I taught him how computers and networks actually
> work; he taught me a lot about the legal system regarding patents.   IMHO,
> they are equally convoluted and complex when viewed from the other's
> perspective.
>
> I also learned a lot about the IMP code, which I had never even looked at
> while I was at BBN.  One task I took on was to exhaustively analyze the
> parts of the IMP code that implemented the "download new instructions"
> functionality, writing up an instruction-by-instruction description of how
> the code accomplished that by interacting with a neighboring IMP.   It was
> a very clever design, and extremely tight code, even including
> self-modifying instructions.   Not easy to figure out (or explain in
> language amenable to a non-technical judge or jury).  So there was great
> interest in being able to demonstrate the code in action using real
> software from the 70s and hardware simulators.   Tangible evidence is much
> better than even expert opinions.
>
> The whole legal project came to a sudden end just a few months prior to
> the first court date.    I was looking forward to going to Delaware (legal
> action was filed in Federal court in Delaware), and finally meeting some of
> the people.   But the parties settled suddenly, the case was dropped, and
> AFAIK the patent question was never resolved.
>
> So, that's a bit about the "Why", for history to ponder.    The experience
> got me wondering about the "patent history" of The Internet.   Clearly
> there was a lot of innovation in those days.   My recollection is that very
> little was patented, even if only to make sure no one else could.   Maybe
> someone will document the patent-related aspects of Internet History
> someday.
>
> /Jack Haverty
>
>
>
> On 9/6/20 12:34 AM, the keyboard of geoff goodfellow wrote:
>
> jack, you've raised my curiosity with respect to:
>
> ... There
> *is* ARPANET IMP software which was recently restored and a small
> ARPANET was run using simulated IMP hardware.
>
> Who/What/When/Where/Why?
>
> geoff
>
> On Sat, Sep 5, 2020 at 8:40 PM Jack Haverty via Internet-history <
> internet-history at elists.isoc.org> wrote:
>
>> Lukasz,
>>
>> I think that the earliest implementations of TTL called it "Time", but
>> I'm not aware that anyone actually used time per se in gateways, at
>> least in the early days (1977-1982 or so).
>>
>> TCP implementations didn't do anything with TTL other than set it on
>> outgoing datagrams, and at least in my implementation (TCP for Unix), it
>> was just set to some arbitrary value.  Until we had some data from
>> experimentation it was hard to evaluate ideas about what routers, hosts,
>> et al should actually do.   The early TCPs did use time in handling
>> retransmission timers, and there was work a bit later to incorporate
>> time more powerfully into TCP behavior, e.g., Van Jacobson's work.
>>
>> The early gateways, IIRC, used the terminology "time", but in practice
>> used just hop counts, since time measurements were difficult to
>> implement.   The exception to that may be Dave Mills' Fuzzballs, since
>> Dave was the implementor most interested in time and making precise
>> measurements of network behavior.   I *think* Dave may have used time
>> values and delay-based routing amongst his "fuzzies".
>>
>> The BBN doc you're seeking might have been one of many that discussed
>> the ARPANET internal mechanisms, e.g., ones with titles like "Routing
>> Algorithm Improvements".  The ARPANET internal mechanisms did use time.
>> It was fairly simple in the IMPs, since the delay introduced by the
>> synchronous communications lines could be easily predicted, and the
>> other major component of delay was the time spent in queues, which could
>> be measured fairly easily.
>>
>> I even found one BBN ARPANET Project QTR from circa 1975 that discussed
>> the merits of the new-fangled TCP proposal that some professor had
>> published -- and seemed to conclude it couldn't possibly work.
>>
>> My involvement in implementations of TCPs and gateways lasted through
>> about mid-1983, so I don't know much of the detail of subsequent
>> implementations.  For the various BBN gateway/router equipment, Bob
>> Hinden would probably be a good source.  The other major early player
>> was MIT and spinoffs (Proteon), which perhaps Noel Chiappa will
>> remember.   There's also at least one paper on the Fuzzballs which may
>> have some details.
>>
>> One thing I'd advise being careful of is the various "specifications" in
>> RFCs.  Much of the wording in those was intentionally non-prescriptive
>> (use of "should" or "may" instead of "must"), to provide as much
>> latitude as possible for experimentation with new ideas, especially
>> within an AS.   The Internet was an Experiment.
>>
>> Also, there was no consistent enforcement mechanism to assure that
>> implementations actually even conformed to the "must" elements.   So
>> Reality could be very different from Specification.
>>
>> I don't know of any gateway implementations that have survived.   There
>> *is* ARPANET IMP software which was recently restored and a small
>> ARPANET was run using simulated IMP hardware.   I still have a ~1979
>> listing of the TCP I wrote for Unix, but haven't scanned it into digital
>> form yet.
>>
>> Jack
>>
>> On 9/5/20 7:38 PM, Łukasz Bromirski wrote:
>> > Jack,
>> >
>> > I was reading a lot of old BBN PDFs thanks to all good souls on
>> > this list that post nice URLs from time to time.
>> >
>> > I remember reading in at least one of them, that apparently first
>> > TCP/IP implementations were indeed using TTL as literally “time”,
>> > not hop count. I believe there somewhere there between PDP docs
>> > and ARPANET docs I’ve read something to the effect “and from this
>> > time we changed from measuring time to simply count routing hops”.
>> > Of course, right now google-fu is failing me.
>> >
>> > Quoting RFC 1009 that was already brought up, there’s quite
>> > direct “definition” of the field:
>> >
>> > "4.8.  Time-To-Live
>> >
>> >  The Time-to-Live (TTL) field of the IP header is defined to be a
>> >  timer limiting the lifetime of a datagram in the Internet.  It is
>> >  an 8-bit field and the units are seconds.  This would imply that
>> >  for a maximum TTL of 255 a datagram would time-out after about 4
>> >  and a quarter minutes.  Another aspect of the definition requires
>> >  each gateway (or other module) that handles a datagram to
>> >  decrement the TTL by at least one, even if the elapsed time was
>> >  much less than a second.  Since this is very often the case, the
>> >  TTL effectively becomes a hop count limit on how far a datagram
>> >  can propagate through the Internet."
>> >
>> > Were there any implementations that survived somewhere and actually
>> > did exactly that - counted actual time/processing delay, not hops?
>> > And if it took 2s to process packet, did they really decrement TTL
>> > by two?
>> >
>> > Thanks for any pointers,
>>
>> --
>> Internet-history mailing list
>> Internet-history at elists.isoc.org
>> https://elists.isoc.org/mailman/listinfo/internet-history
>>
>>
>
> --
> Geoff.Goodfellow at iconia.com
> living as The Truth is True
>
>
>
>
>

-- 
Geoff.Goodfellow at iconia.com
living as The Truth is True