[ih] X.25

[Brian E Carpenter]

On 02-Oct-25 14:00, John Demco via Internet-history wrote:
> I was at UBC back then, and among other things I managed CDNnet. Its
> email service was used for a number of purposes we didn’t initially
> foresee. For example, in addition to the UUCP-related traffic Lyndon
> mentions, it was used by clients of the Canadian Microelectronics
> Corporation to assist in chip design, checking, and fabrication.
> 
> UBC was also a member of CSnet—an international affiliate, if I remember
> correctly—and a growing volume of email traffic was gatewayed between
> CDNnet and the wider Internet via CSnet. UBC’s Ean X.400 software (due
> mainly to Gerald Neufeld, Rick Sample, and Brent Hilpert) found use in a
> number of European networks and elsewhere, and by 1986 there was an
> increasing amount of email flowing between these networks and the
> Internet, via CDNnet and CSnet.
> 
> (By the way, as Lyndon also mentions, Ean’s default configuration was to
> present X.400 addresses in user at host.domain style, but it could also
> represent X.400 addresses more directly, e.g.
> S=Demco;OU=CS;O=UBC;P=cdn;A=telecom.canada;C=ca.)

Yep. Brent Hilpert visited my team at CERN in 1985 or 1986, as
we had decided to use EAN to bridge the emerging Internet email
community with the expected X.400/X.500 community. We also paid
Steve Kille to work with us for a couple of months the same year,
setting up EAN and his own X.400 package.

When the X.400/X.500 community failed to appear, I recall writing
scripts to convert EAN mail folders to MBOX format, so that we could
easily move residual EAN users to ELM. That was probably in 1988 or 1989.

(JANET was bravely trying to use X.400 as an interchange format, so
I do have one message in my archive whose entire header is:

 From Anon  Tue Dec 15 8:27:19 1987
Originator:    HARRIS at vax1.physics.oxford.ac.uk
From:       <HARRIS at vax1.physics.oxford.ac.uk>
To:         BRIAN <BRIAN%priam.cern at ean-relay.ac.uk>
Reply-To:   <HARRIS at vax1.physics.oxford.ac.uk>
Message-ID: addresses:1
Subject:    [redacted]
Status: RO

)

     Brian

> 
> The growth of costs (especially due to international X.25 charges) was a
> major motivation in establishing a leased line link between CDNnet/BCNET
> in Vancouver and NorthWestNet in Seattle. This was suggested to me by
> Larry Landweber at the 1986 academic network workshop in Dublin hosted
> by Dennis Jennings, and enabled by several others including Hellmut
> Golde and Dan Jordt at UW, Steve Wolff at NSF, and Jack Leigh at UBC.
> The link became operational in 1988, and grew into one of the three
> north-south links between the CA*net and NSFnet backbones in 1990.


> 
> John Demco
> 
> On 2025-10-01 14:55, Lyndon Nerenberg (VE7TFX/VE6BBM) via
> Internet-history wrote:
>> Dave Crocker writes:
>>> On 10/1/2025 2:15 PM, Lyndon Nerenberg (VE7TFX/VE6BBM) via
>>> Internet-history wrote:
>>>> I think X.25 got more of a workout as a transport layer for UUCP
>>>> (f protocol).  UUCP over X.25 hauled a lot of email and Usenet
>>>> traffic in the 1980s.
>>>
>>> I don't recall any of the details about this for UUCP.  For CSNet, we
>>> used X.28/X.29, treading the path as a simple dial-up channel.
>>>
>>> Was there a protocol layer between UUCP and X.25.  The OSI model called
>>> it a 'convergence' layer.
>> Well, yes.  The X.28/X.29 PAD interface was implied.
>>
>> But UBC did a native X.25 implementation for 42BSD.  In fact, they
>> did a pretty substantial ISO stack.  This ran at a number of Canadian
>> universities, and was the foundation for CDNnet -- a Canadian X.400
>> email network that ran in the 1980s.  The X.400 addresses mapped
>> to 822-style addresses as user at host.cdn.  Several UUCP sites in
>> Canada could gateway to the X.400 network using the
>> .cdn pseudo-domain.  They probably didn't advertise that in the UUCP
>> maps.
>>
>> Hopefully someone from UBC is lurking and can provide more details.
>> I wan't involved in any of this, and my memory is a wee bit fuzzy.
>>
>> --lyndon
>>
>> P.S.  When country TLDs became A Thing, there was some debate in
>> Canada whether we should adopt .cdn as our TLD, since it was already
>> in use for the X.400 network.  Thankfully, sanity prevailed.
>