At the start of the GOSIP nonsense, that might have been a reasonable
charge. By the middle, there were at least as many ISO OSI
applications as there are now IPv6 applications, and there was a
lot of real OSI traffic in Europe. (A "lot" for that era if not
today.) Major host vendors were supporting OSI protocols by the
end of GOSIP as well as they are now supporting IPv6. OSI support
was a required checklist item in a lot of sales situations.
Well, you have to seriously qualify what you call "a lot". The only
non-TCP-IP network service that got widely deployed in Europe was X.25.
Most of its use was not strictly OSI: asynchronous modem connections
according to X.28 and X.29, or enterprise networks using X.25 as a lease
line replacement, much like modern-day VPN. Some of that is still in use
today, e.g. for the French "Minitel" service.
The only OSI service that had significant deployment was the mail
system, X.400. It was used for some research networks, very often
through gateways with SMTP mail. It was also used for exchange of
documents between enterprises in specialized EDI networks.
An aggravating factor in the GOSIP story was the lack of agreement on
the network + transport stack. The US proposed the IP-like CLNP and the
TCP-like TP4, the European X.400 deployments mostly used X.25 and TP0
(null transport), and ECMA was pushing a null network layer combined
with TP4 for European enterprise networks.
The academics who were using X.400 and experimenting with X.500 quickly
moved to a combination of TCP-IP and TP0 (RFC 987, RFC 1006), because
TCP-IP was more accessible than either X.25 or CLNP. Most X.400 MTA used
in academic networks where dual stack, i.e. able to translate between
X.400 and RFC 822, and most of the traffic moved quickly to plain SMTP.
Similarly, the X.500 experiments resulted in LDAP, i.e. a TCP-IP
application.
Bottom line, there never was a significant usage of CLNP in Europe.
-- Christian Huitema