This is quite interesting discussion going back into the roots of the
current networking (which is in many ways quite a useful exercise, yet
not performed often enough). I wish my father who was quite active in
these network-forming days could add his knowledgeable views here -
unfortunately, it is no more possible. At least I can add some notes
from his publications to (hopefully) enhance the discussion below:
"Howard C. Berkowitz" wrote:
> ITU-T didn't exist yet. CCITT was the ancestor, and its first X.25
> standards were in the 1972 books (I forget the color now--probably
> yellow or orange).
CCITT was converted to ITU-T in 1993 (March). Recommendations (they have
never used standard for their approved deliverables) before 1993, valid
ones, are still referred as CCITT. The newer ones have the ITU-T
denomination.
For information (using my father's notes) the CCITT
books-of-recommendations' colors were the following:
- green in 1972,
- yellow in 1980,
- red in 1984
- blue in 1988 (last 4-year-book).
Currently they (ITU-T) may still refer to individual recommendations as
"white books" (which for us locally has very different connotation: "To
join or not to join the EU" ;-)
> That used LAP. The first commercial X.25
> networks deployed in 1972, the first a banking network in Spain and
> then Telenet a few months afterward.
>
> LAP-B was in the X.25 1976 standards.
At that time X.25 was not in compliance with then worked on OSI model.
But it changed a lot over time, in 1984 X.25 was a source for ISO 8208
and nowadays it complies fully with bottom OSI reference model.
>
> LLC 3 was developed by the MAP project, primarily General Motors, and
> I don't think it ever became a full IEEE specification. It certainly
> isn't in my copy of 802.2.
>
This is interesting, because there are approved IEEE (and endorsed
ISO/IEC) stnds on management objects and PICS proforma for Type 3. I
will check the latest 802.2 version once I use up the new wave in IEEE
allowing us to download all the 802 standards.
BTW looking through the IEEE standards status report, I have come across
even another LLC Type - Type 4 (1991):
"Supplement to 802.2, Information Processing Systems
- Local Area Networks: Logical Link Control (LLC) Type 4
High Speed, High Performance Operation "
But status sweeps my expectations away:
"Status: Withdrawn PAR. Standards project no longer endorsed
by the IEEE. "
Rita
Message Posted at:
http://www.groupstudy.com/form/read.php?f=7&i=8325&t=8262
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