[ih] How long did it take?

Thu Sep 17 03:55:51 PDT 2026

from gemini
The development of Datapac in *Canada
<https://www.google.com/search?kgmid=/m/0d060g>* was led by Bell-Northern
Research (BNR)—a joint venture between Bell Canada and Northern Telecom.
[1]
The primary engineering and architectural mastermind behind Canada's
Datapac deployment was Tony Rybczynski. He served as the chief architect of
Datapac’s Standard Network Access Protocol (SNAP), which directly evolved
into the X.25 standard. [2, 3]
------------------------------
The Leaders of the X.25 Standardization Consortium
The international effort to create the CCITT X.25 standard in 1976 was a
historic collaboration between four major pioneering packet-switching data
network teams. The key leaders who spearheaded this harmonization effort
included: [4, 5]

   -
   - Canada (Datapac): Tony Rybczynski
   Rybczynski led the Canadian delegation. He originally championed a
   datagram-based architecture (SNAP) but collaborated heavily to bridge the
   gap with European virtual-circuit methodologies. [2, 3]
   - France (Transpac): *Rémi Després
   <https://www.google.com/search?q=r%C3%A9mi+despr%C3%A9s&kgmid=/m/0h3r0w5>*
   and Philippe Picard
   *Després <https://www.google.com/search?q=despr%C3%A9s&kgmid=/m/0h3r0w5>*
   was the technical architect of Transpac and a massive advocate for
   connection-oriented virtual circuits. Alongside Picard, *Després
   <https://www.google.com/search?q=despr%C3%A9s&kgmid=/m/0h3r0w5>* worked
   closely with *Rybczynski
   <https://www.google.com/search?q=rybczynski&kgmid=/m/04cvbp>* during a
   legendary drafting session in Paris to combine the Canadian and French
   approaches into a unified protocol. [3, 6]
   - United States (Telenet): *Dr. Lawrence (Larry) Roberts
   <https://www.google.com/search?q=dr.+lawrence+%28larry%29+roberts&kgmid=/m/08vrqn>*
   and *Barry Wessler
   <https://www.google.com/search?q=barry+wessler&kgmid=/g/11f0ty_tf6>*
   After leaving ARPA (where *Roberts
   <https://www.google.com/search?q=roberts&kgmid=/m/08vrqn>* had managed
   the ARPANET), they founded the commercial network Telenet. *Roberts
   <https://www.google.com/search?q=roberts&kgmid=/m/08vrqn>* and Wessler
   joined the international effort just before it finalized to ensure
   commercial US interests were aligned with the international standard. [5]
   - United Kingdom (EPSS / British Post Office): Paul Guinaudeau and *Halvor
   Bothner-By
   <https://www.google.com/search?q=halvor+bothner-by&kgmid=/g/11lpwhfp90>*
   Representing the UK's Experimental Packet Switched Service (EPSS) and
   the British Post Office (BPO), they provided crucial framework
   recommendations. [4]
   -

The Final Push
The ultimate consensus was hammered out during an intense drafting meeting
in Ottawa, Canada in March 1975. To hit their tight 1976 deadline for the
CCITT plenary, Tony Rybczynski and Paul Guinaudeau famously spent an entire
night hand-writing negotiated amendments and physically pasting the final
documents together using scissors and glue. Their combined efforts resulted
in the unanimous approval of the X.25 "Orange Book" standard in September
1976. [2, 4, 7]
If you would like, we can explore:

   -
   - How the "Protocol Wars" played out between X.25 and TCP/IP
   - The technical design of the SL-10 switch built by Northern Telecom for
   Datapac
   - How Minitel later leveraged France's Transpac network
   -

Let me know what area you want to examine next!

[1] https://en.wikipedia.org
<https://en.wikipedia.org/wiki/List_of_packet-switched_networks>
[2] https://en.wikipedia.org <https://en.wikipedia.org/wiki/DATAPAC>
[3] https://www.researchgate.net
<https://www.researchgate.net/publication/262166466_X25_virtual_circuits_transpac_in_France_-_pre-internet_data_networking>
[4] https://en.wikipedia.org <https://en.wikipedia.org/wiki/X.25>
[5] https://en.wikipedia.org <https://en.wikipedia.org/wiki/Protocol_Wars>
[6] https://www.ahti.fr
<https://www.ahti.fr/cahiers/c12/HISTORY%20OF%20TRANSPAC%20%28R.%20Despres%29.pdf>
[7] https://en.wikipedia.org <https://en.wikipedia.org/wiki/X.25>

On Thu, Sep 17, 2026 at 6:13 AM John Day via Internet-history <
internet-history at elists.isoc.org> wrote:

> Yes, everyone else was doing it and as I remember badly, except possibly
> Datapac.
>
> But when did AT&T finally start development of what failed? I am just
> curious.
>
> > On Sep 17, 2026, at 04:35, Olivier MJ Crépin-Leblond via
> Internet-history <internet-history at elists.isoc.org> wrote:
> >
> > Services running on TRANSPAC made lots of money.
> > https://en.wikipedia.org/wiki/Transpac_(data_network)
> >
> > Kindest regards,
> >
> > Olivier
> >
> > On 17/09/2026 06:39, Brian E Carpenter via Internet-history wrote:
> >> DATAPAC "opened for use in 1976 as the world's first public data
> network designed specifically for X.25." [Wikipedia]
> >>
> >> Canada won, thanks to Peter Cashin and his experience at NPL under
> Donald Davies. DATAPAC was definitely first in the world, before PSS
> (Packet Switch Stream) was operational in the UK.
> >>
> >> Regards/Ngā mihi
> >>    Brian
> >>
> >> On 17-Sep-26 14:59, Dave Crocker via Internet-history wrote:
> >>>
> >>>> If the X.25 service came out in 83
> >>>
> >>>
> >>> It came out earlier than that.  In the NSF meeting that produced CSNet,
> >>> circa 1981, there was general awareness that X.25 was already
> >>> commercially deployed.  Most folk thought the proffered services were
> >>> like the Arpanet's host-host packet service and were quite surprised to
> >>> hear the, really, what was being sold for customers was X.28/X.29 --
> ie,
> >>> telnet.
> >>>
> >>> The initial email-based dial-up CSNet service was the fallback, for
> >>> initial operation.
> >>>
> >>> I don't know when 'raw' X.25 became a viable commercial service.
> Perhaps
> >>> that what the above 1983 date meant?
> >>>
> >>> d/
> >>>
> >
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