[ih] Better-than-Best Effort
Vint Cerf
vint at google.com
Sun Aug 29 07:28:20 PDT 2021
my recollection matches Alex' in this case
v
On Sun, Aug 29, 2021 at 10:04 AM Alex McKenzie via Internet-history <
internet-history at elists.isoc.org> wrote:
> This is the second email from Jack mentioning a point-to-point line
> between the ARPA TIP and the ISI site. I don't believe that is an accurate
> statement of the ARPAnet topology. In January 1975 there were 5 hops
> between the 2 on the shortest path. In October 1975 there were 6. I don't
> believe it was ever one or two hops, but perhaps someone can find a network
> map that proves me wrong.
> Alex McKenzie
>
> On Saturday, August 28, 2021, 05:06:54 PM EDT, Jack Haverty via
> Internet-history <internet-history at elists.isoc.org> wrote:
>
> Sounds right. My experience was well after that early experimental
> period. The ARPANET was much bigger (1980ish) and the topology had
> evolved over the years. There was a direct 56K line (IIRC between
> ARPA-TIP and ISI) at that time. Lots of other circuits too, but in
> normal conditions ARPA<->ISI traffic flowed directly over that long-haul
> circuit. /Jack
>
> On 8/28/21 1:55 PM, Vint Cerf wrote:
> > Jack, the 4 node configuration had two paths between UCLA and SRI and
> > a two hop path to University of Utah.
> > We did a variety of tests to force alternate routing (by congesting
> > the first path).
> > I used traffic generators in the IMPs and in the UCLA Sigma-7 to get
> > this effect. Of course, we also crashed the Arpanet with these early
> > experiments.
> >
> > v
> >
> >
> > On Sat, Aug 28, 2021 at 4:15 PM Jack Haverty <jack at 3kitty.org
> > <mailto:jack at 3kitty.org>> wrote:
> >
> > Thanks, Steve. I hadn't heard the details of why ISI was
> > selected. I can believe that economics was probably a factor but
> > the people and organizational issues could have been the dominant
> > factors.
> >
> > IMHO, the "internet community" seems to often ignore non-technical
> > influences on historical events, preferring to view everything in
> > terms of RFCs, protocols, and such. I think the other influences
> > are an important part of the story - hence my "economic lens".
> > You just described a view through a manager's lens.
> >
> > /Jack
> >
> > PS - I always thought that the "ARPANET demo" aspect of that
> > ARPANET timeframe was suspect, especially after I noticed that the
> > ARPANET had been configured with a leased circuit directly between
> > the nearby IMPs to ISI and ARPA. So as a demo of "packet
> > switching", there wasn't much actual switching involved. The 2
> > IMPs were more like multiplexors.
> >
> > I never heard whether that configuration was mandated by ARPA, or
> > BBN decided to put a line in as a way to keep the customer happy,
> > or if it just happened naturally as a result of the ongoing
> > measurement of traffic flows and reconfiguration of the topology
> > to adapt as needed. Or something else. The interactivity of the
> > service between a terminal at ARPA and a PDP-10 at ISI was
> > noticeably better than other users (e.g., me) experienced.
> >
> > On 8/28/21 11:51 AM, Steve Crocker wrote:
> >> Jack,
> >>
> >> You wrote:
> >>
> >> I recall many visits to ARPA on Wilson Blvd in Arlington, VA.
> >> There were
> >> terminals all over the building, pretty much all connected
> >> through the
> >> ARPANET to a PDP-10 3000 miles away at USC in Marine Del Rey,
> >> CA. The
> >> technology of Packet Switching made it possible to keep a
> >> PDP-10 busy
> >> servicing all those Users and minimize the costs of everything,
> >> including those expensive communications circuits. This was
> >> circa
> >> 1980. Users could efficiently share expensive communications, and
> >> expensive and distant computers -- although I always thought
> >> ARPA's
> >> choice to use a computer 3000 miles away was probably more to
> >> demonstrate the viability of the ARPANET than because it was
> >> cheaper
> >> than using a computer somewhere near DC.
> >>
> >>
> >> The choice of USC-ISI in Marina del Rey was due to other
> >> factors. In 1972, with ARPA/IPTO (Larry Roberts) strong support,
> >> Keith Uncapher moved his research group out of RAND. Uncapher
> >> explored a couple of possibilities and found a comfortable
> >> institutional home with the University of Southern California
> >> (USC) with the proviso the institute would be off campus.
> >> Uncapher was solidly supportive of both ARPA/IPTO and of the
> >> Arpanet project. As the Arpanet grew, Roberts needed a place to
> >> have multiple PDP-10s providing service on the Arpanet. Not just
> >> for the staff at ARPA but for many others as well. Uncapher was
> >> cooperative and the rest followed easily.
> >>
> >> The fact that it demonstrated the viability of packet-switching
> >> over that distance was perhaps a bonus, but the same would have
> >> been true almost anywhere in the continental U.S. at that time.
> >> The more important factor was the quality of the relationship.
> >> One could imagine setting up a small farm of machines at various
> >> other universities, non-profits, or selected for profit companies
> >> or even some military bases. For each of these, cost,
> >> contracting rules, the ambitions of the principal investigator,
> >> and staff skill sets would have been the dominant concerns.
> >>
> >> Steve
> >>
> >
> >
> >
> > --
> > Please send any postal/overnight deliveries to:
> > Vint Cerf
> > 1435 Woodhurst Blvd
> > McLean, VA 22102
> > 703-448-0965 <(703)%20448-0965>
> >
> > until further notice
> >
> >
> >
>
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--
Please send any postal/overnight deliveries to:
Vint Cerf
1435 Woodhurst Blvd
McLean, VA 22102
703-448-0965
until further notice
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