[ih] Question re rate of growth of the Arpanet

[vinton cerf]

John is right about 2.4 KB/s original plan. The 1967 ACM event where Roger
met Larry changed things.

V

On Mon, Apr 21, 2025, 14:36 John Day via Internet-history <
internet-history at elists.isoc.org> wrote:

> Yes, I thought so too.  My quoting 2.4 was based on the paper Roberts gave
> at the Gatlinburg conference.
>
> Ah, so the government had a special tariff, so it wasn’t quite as
> expensive as I thought. Still far greater than a campus network, but
> better.  ;-)
>
> > On Apr 21, 2025, at 14:32, Steve Crocker via Internet-history <
> internet-history at elists.isoc.org> wrote:
> >
> > Geoff,
> >
> > To add a bit more, I believe Larry Roberts was originally thinking in
> terms
> > of 9600 baud lines.  However, he discovered the U.S. Government had
> access
> > to a special Bell tariff for these 50 kb/s circuits.  As Vint said, the
> 50
> > kb/s was implemented using twelve voice grade circuits and a Western
> > Electric series 303A modem.  Bottom line, Larry found this item in the
> > government catalog that provided this bandwidth and was within his
> budget.
> >
> > Steve
> >
> >
> > On Mon, Apr 21, 2025 at 2:11 PM Vint Cerf <vint at google.com> wrote:
> >
> >> Best you could do with 12 3KHz bonded channels on a Bell 303 modem
> >>
> >> V
> >>
> >> Please send any postal/overnight deliveries to:
> >> Vint Cerf
> >> Google, LLC
> >> 1900 Reston Metro Plaza, 16th Floor
> >> Reston, VA 20190
> >> +1 (571) 213 1346
> >>
> >>
> >> until further notice
> >>
> >>
> >>
> >>
> >> On Mon, Apr 21, 2025, 14:09 the keyboard of geoff goodfellow via
> >> Internet-history <internet-history at elists.isoc.org> wrote:
> >>
> >>> steve, can you elucidate any history with respect to how/why the speed
> of
> >>> 50 kb/s was chosen for the ARPANET lines?  were there great speeds
> >>> available then?
> >>>
> >>> yours truly kinda (perhaps mistakenly) recalls these 50 kb/s "wideband
> >>> circuits of the day" were primarily used for linking tv broadcast
> >>> affiliate
> >>> stations to/with their motherships (cbs, nbc, abc, ...)?
> >>>
> >>> geoff
> >>>
> >>> On Mon, Apr 21, 2025 at 7:26 AM Steve Crocker via Internet-history <
> >>> internet-history at elists.isoc.org> wrote:
> >>>
> >>>> Thanks for the pointer to RFC 597.
> >>>>
> >>>> As I looked at it, an aspect I hadn't considered before came to mind.
> >>>>
> >>>> Installation of an IMP required provisioning 50 kb/s lines to two or
> >>> three
> >>>> other points.  In the early days, we installed roughly a new IMP once
> a
> >>>> month.  (The lead time for ordering 50 kb/s lines from AT&T was NINE
> >>>> months.)
> >>>>
> >>>> Once an IMP was installed, new hosts could be added to the IMP as
> >>> quickly
> >>>> as the site could build or obtain the host-IMP interface and write or
> >>>> obtain the software for their operating system.
> >>>>
> >>>> If anyone has the dates for each of the hosts, it would be interesting
> >>> to
> >>>> compare the growth of IMPs vs growth of hosts.
> >>>>
> >>>> Steve
> >>>> --
> >>>> 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
> >>> --
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> >>> https://elists.isoc.org/mailman/listinfo/internet-history
> >>>
> >>
> >
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