>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).
mutters because I distinctly remember an Orange Book. 1976?
>
>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" ;-)
I can't resist...perhaps someone in the Vast Listening Audience
remembers the factoid that has been escaping me since my
international relations classes 30 years ago.
We speak a lot about "white papers." Around the turn of the 20th
century, each Great Power issued diplomatic positions with a cover
and/or paper of a certain color. White, I believe, was the British
Foreign Office. The French might have been green. I simply don't
remember the system, but there was one.
Presumably any country that issued Black Books, but continued to use
black ink, suffered at a significant diplomatic disadvantage.
Anyone happen to remember the specific system? Even better yet, a
good reference on diplomatic practice -- the differences between
demarches, aide-memoires, ultimata, etc.?
>
>> 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.
It was much uglier than that. There are features in the OSI
definition of the connection-oriented network service that were there
simply because they were used in X.25, but they belonged at other OSI
layers. The D-bit, for example, is clearly a transport function.
You are quite correct that there was evolution, including in the OSI
Reference Model itself. Especially important (don't have numbers in
front of me) were the Internal Organization of the Network Layer and
the OSI Routeing Framework. Once one understands these
specifications, many of the arguments over "what layer does XXX go
into" disappear, because the definitions of layers have evolved.
Look at ISO 8880 and 8881, CONS over Ethernet and CLNP over X.25.
> >
>
>> 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.
Indeed, it might have been added. My 802.2 document is the original
IEEE hard cover specification. There's no question there were MIBs
for MAP/Enhanced Performance Architecture/etc.; I worked on
conformance testers for them, especially their management. I will
observe that most of these MIBs were not written as IETF-style SMI,
but OSI GDMO.
>
>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
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