[ih] Better-than-Best Effort

[Vint Cerf]

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> 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

until further notice