[ih] Question re rate of growth of the Arpanet

[John Day]

The benefits of checking the sources.  As I said, I thought it was 9.6 too until I dug into it.  ;-)

2.4 would have been *really* slow!!

> On Apr 21, 2025, at 14:55, vinton cerf <vgcerf at gmail.com> wrote:
> 
> 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 <mailto: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 <mailto: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 <mailto: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 <mailto: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 <mailto: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
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>> >>>> 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
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>> >>> https://elists.isoc.org/mailman/listinfo/internet-history
>> >>> 
>> >> 
>> > 
>> > -- 
>> > Sent by a Verified
>> > 
>> > sender
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