[ih] How long did it take?

Thu Sep 17 17:20:34 PDT 2026

On Wed, Sep 16, 2026 at 5:10 PM John Day <jeanjour at comcast.net> wrote:

> Yes of course we know that. But that wasn’t what I asked.
>

ok, so how about this Grok conversational exchange then:

TO GROK:
*it's said that in the 60s, Paul Baran backed out of an offer from AT&T to
build a packet switched network because he sensed wisely they didn’t
believe in it and would not put the effort into to make it real.  any ideas
of when did AT&T start to take packet switching seriously?*

GROK REPLY:
"The story is essentially right in spirit, though the mechanics were a bit
different from “AT&T made him an offer and he walked away.”

In the mid-1960s the Air Force was interested in Baran’s distributed
“message-block” (packet) design. AT&T was the obvious builder. AT&T
engineers rejected it on technical and institutional grounds—“it can’t
work, and if it did we don’t want a competitor to ourselves”—and the
Defense Communications Agency that would have overseen any implementation
was staffed largely by people with analog-circuit backgrounds. Baran
concluded they would either botch the project or quietly kill it, so he
recommended that the whole effort be shelved rather than handed to them.
The project was quietly dropped around 1966. ARPA later picked up the ideas
(plus Donald Davies’s independent work) and built ARPANET without AT&T.
When the Pentagon asked AT&T in the early 1970s whether it wanted to take
over ARPANET and turn it into a public service, AT&T declined again. [
https://www.nytimes.com/2011/03/28/technology/28baran.html]

AT&T’s own conversion happened in stages:

   - Late 1970s–early 1980s: Bell Labs (Sandy Fraser) developed Datakit, a
   proprietary virtual-circuit packet switch. Internal test switches appeared
   around 1979; it became an AT&T product in 1983 and was widely used inside
   the Bell System for operations-support systems. This was the first time the
   company treated packet switching as something it would actually build and
   operate at scale. [https://www.youtube.com/watch?v=ojRtJ1U6Qzw]
   - 1984: AT&T launched Accunet Packet Service, a public X.25 network
   (tariff effective August 1984). That was its first commercial packet
   offering to customers. [
   https://bitsavers.trailing-edge.com/pdf/dataDecisions/1985_Communications_Systems/Vol2_810.pdf
   ]
   - Early 1990s: Frame Relay and ATM services followed.
   - Late 1990s: AT&T installed its last new 4ESS circuit switch (1999) and
   publicly described the future of the network as packet-based. Data traffic
   overtook voice on the AT&T network around 2000 [
   https://web.archive.org/web/20070107114157/http:/www.corp.att.com/history/nethistory/milestones.html
   ]

So the company began taking packet switching seriously for its own internal
use in the late 1970s and for paying customers in 1984—roughly 15–20 years
after Baran’s original proposal and a decade after Telenet and Tymnet had
already commercialized it."

➔➔https://x.com/i/grok?conversation=2100738437875892246

On Sep 16, 2026, at 20:05, the keyboard of geoff goodfellow <
> geoff at iconia.com> wrote:
>
> Grok sez:
>
> AT&T operated X.25 packet-switched networks in the 1980s.
>
> The main one was ACCUNET Packet Service, a public data network that AT&T
> launched as a regulated basic service. The FCC tariff took effect 18 August
> 1984. By 1986 it had 99 service points in the U.S. Subscriber interfaces
> followed CCITT X.25 (1980 recommendation, with a later move toward the 1984
> version). It offered switched virtual calls and permanent virtual circuits
> over access lines at 4.8, 9.6, and 56 kbps (via Dataphone Digital Service
> or analog private lines). Nodes were interconnected with 56 kbps DDS
> facilities.
>
> AT&T also ran a separate value-added X.25 service called Net 1000 (AIS*Net
> 1000) through its unregulated subsidiary (American Bell / AT&T Information
> Systems). That offering added protocol conversion, processing, and storage
> on top of an underlying X.25 packet network supplied by the regulated side
> of AT&T. It was withdrawn in 1986 after large losses.
>
> After the 1984 breakup, the long-distance AT&T entity continued ACCUNET
> Packet Service while the Regional Bell Operating Companies offered their
> own intra-LATA X.25 packet services (some of those RBOCs later became part
> of today’s AT&T). Bell Labs also did packet-switching research and built
> systems such as LADT that used X.25 internally.
>
> AT&T was late to commercial packet switching compared with Telenet and
> Tymnet, but it did own and operate X.25 networks once it entered the market.
>
> ➔➔https://x.com/i/grok?conversation=2100374688069489036
>
>
> On Wed, Sep 16, 2026 at 4:07 PM John Day via Internet-history <
> internet-history at elists.isoc.org> wrote:
>
>> In the 60s, Baran backed out of an offer from AT&T to build a packet
>> switched network because he sensed wisely they didn’t believe in it and
>> would not put the effort into to make it real.
>>
>> We also all know the story from the ARPANET demo at ICCC72 when Bob
>> Metcalfe was demoing the TIP to several AT&T attendees. The TIP crashed and
>> re-booted from its neighbors. Bob thought this was a great aspect of the
>> system. The AT&T guys thought it showed the ARPANET was a joke and not
>> serious.
>>
>> So when did AT&T start to take packet switching seriously?
>>
>> Take care,
>> John
>> --
>>
>>
-- 
Geoff.Goodfellow at iconia.com
living as The Truth is True