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

Vint Cerf vint at google.com
Mon Sep 7 04:13:43 PDT 2020


Packet Radios were developed by Collins Radio. I do not recall that they
downloaded from neighbors.

As to the 1976 report, there was a famous test from Rosati's. There was an
LSI-11 "terminal" connected to a packet radio. My guess is that they would
have just TELNETTED into a PDP-10 at SRI and delivered the report that way.
I doubt that they had email running in the LSI-11.

v


On Mon, Sep 7, 2020 at 2:47 AM Barbara Denny via Internet-history <
internet-history at elists.isoc.org> wrote:

>  Because of BBN's involvement, I am thinking Packet Radio might have
> reused many of  the same ideas as the IMPs for loading new software from
> another node. Do you know this was not the case?  I never needed to look at
> that part of the code.
> I remember using XNET for examination of the Packet Radio station. Given
> your recent email it sounds like you looked for old Packet Radio station
> software and couldn't find it. Is this correct?
> I don't think Rockwell released their Packet Radio software in the late
> 70s/early 80s. I would have to contact Rockwell if I thought bugs required
> a change to a packet radio, versus the Packet Radio station, when I worked
> at BBN. I know several years later SRI did get some of their code  because
> I implemented one of the new routing algorithms ( I am pretty sure it was
> called threshold distance vector routing if anyone is interested). BTW, I
> think the software may have only been tested in a simulator due to delays
> in the delivery of the LPR (Low Cost Packet Radio). This was during the
> SURAN program.
> The first demo of Packet Radio and ARPANET in 1976 involved submitting the
> status report.  Don Nielson would probably remember if that was done
> through anything like email. Below is a link to an article that discusses
> this event. The text from the article mentions email but more importantly
> it has a link to a podcast with Don. I didn't know this podcast existed so
> I still need to listen to it.  I can see why you might think the report
> submission may have been done by using a telnet connection to a SRI host
> that had email.
>
> https://hightechforum.org/happy-birthday-internet-richard-bennett-talks-with-don-nielson/
> barbara
>     On Sunday, September 6, 2020, 12:39:38 PM PDT, Jack Haverty via
> Internet-history <internet-history at elists.isoc.org> wrote:
>
>  Hi Geoff - thanks for that bit of history and kudos!
>
> I think there's an Internet connection in your experience.  I'm not sure
> what, legally, "wireless email" means.  But I suspect that email was
> being sent and received, wirelessly, well before even 1982, if only to
> and from the SRI Packet Radio van that could occasionally be seen then
> roaming around the Bay Area.
>
> Of course, technically, that probably involved a Telnet connection,
> wirelessly, to some PDP-10 running an email program.   But, legally, it
> might meet the court accepted definition of "wireless email".   I
> learned from the lawyers that much of litigation involves arguing about
> the meaning of words and phrases.
>
> So, perhaps someone could have looked for mouldering Packet Radio (aka
> PR) hardware and software, and demonstrated wireless email circa 1978
> over one or more PRNETs.
>
> Sadly, although I was pretty sure that interesting "prior art" would be
> found in the PR environment, we had little success 7 years ago while
> trying to find anything that might show exactly how PR equipment
> "downloaded instructions".
>
> There's remarkably little readily discoverable material about lots of
> the computer and network systems of the 70s/80s, especially internal
> details of operation, tools, procedures, etc.   Plenty of stuff on
> Routing, but little on other mechanisms, or other types of networks of
> that era, at least that the lawyers and I could find.   IMHO, that's a
> huge gap even in Internet History, since the Internet did not evolve in
> a vacuum, was itself composed of more than the ARPANET, and was
> surrounded by competitors (remember multiprotocol routers).
>
> /Jack
>
> On 9/6/20 11:58 AM, the keyboard of geoff goodfellow wrote:
> > 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
> > <mailto:jack at 3kitty.org>> wrote:
> >
> >    Geoff,
> >
> >    Dave's IEEE paper does an excellent job of the
> >    Who/What/When/Where <https://teams.googleplex.com/u/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
> <https://teams.googleplex.com/u/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
> >>    <mailto: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
> >>        <mailto:Internet-history at elists.isoc.org>
> >>        https://elists.isoc.org/mailman/listinfo/internet-history
> >>
> >>
> >>
> >>    --
> >>    Geoff.Goodfellow at iconia.com <mailto:Geoff.Goodfellow at iconia.com>
> >>    living as The Truth is True
> >>
> >>
> >>
> >
> >
> >
> > --
> > Geoff.Goodfellow at iconia.com <mailto:Geoff.Goodfellow at iconia.com>
> > living as The Truth is True
> >
> >
> >
>
> --
> Internet-history mailing list
> Internet-history at elists.isoc.org
> https://elists.isoc.org/mailman/listinfo/internet-history
>
>
>
> --
> Internet-history mailing list
> Internet-history at elists.isoc.org
> https://elists.isoc.org/mailman/listinfo/internet-history
>


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