[ih] "The Great Debate"

[Karl Auerbach]

(By-the-way, where is Marshall Rose these days?  He and I got off on the 
wrong foot and I wish we would have agreed more and fought less.)

While Marshall was doing ISODE/CMOT I had purchased many of the colored 
volumes from the ITU or whomever and I had set forth to build a working 
X.400 - the first obstacle being ASN.1.

(By-the-way, I don't think it is fair to complain that ISODE/CMOT were 
too large and slow - they were prototypes for experimentation.  I 
remember TCP implementations that were large and ugly - such as the U of 
Illinois implementation for early Unix on PDP-11 that swapped between a 
"small daemon" and a "large daemon" depending on connection state.)

As for OSI - OMG!!  What a nightmare.  Nary a word of explanation why 
things were as they were, lots of insider phrases, and a design that was 
so open ended that it amounted to the equivalent of a Rube Goldberg 
airliner, complete with bowling alley, Olympic swimming pool, golf 
driving range, and a coal powered steam boiler.

(I fear that RFC's coming out of the IETF are slowly walking the same 
road towards incomprehensibility and lack of explanation (especially 
with regard to paths not taken) that helped to sink ISO/OSI.)

There were nuggets of value in there, but they were not easily 
detectable or identifiable among the mountain of dross.

I did an implementation in which I threw out most of ASN.1 complexity 
and ended up with a basic-encoding-rules (BER) engine that worked nicely 
when SNMP came along.

OSI had some good ideas such as:

    - Connection time data (which in the TCP world would have made TLS 
and virtual websites a lot easier)

    - A session layer - which is a nice way to span application level 
relationships that span the failure and reconstruction of underlying 
transport connections as devices move about.  This could have greatly 
simplified IP mobility and simplified context-keeping things like web 
cookies.

    - A nice way to specify protocol services to the next higher layer 
and a distinct way to specify what was happening internal to the 
protocol.  (Dave Kaufman and I wrestled with the need for this kind of 
expression when we were trying to do security protocols at SDC - the OSI 
folks did a better job of it than we did.)

    - The Fletcher checksum (it looks scary, but there are good ways to 
implement it and also to do incremental updates.)

   - Things like "application titles" that would help in a world of 
cloud-like computing by allowing services to split (sorcerer's 
apprentice style), merge, or move while maintaining a client-service 
context.

    - An object identifier hierarchy.  (The OSI version was sane, what 
we did to it in SNMP by imposing "lexiographic ordering" was not nice - 
I wrote and did a prototype implementation of an alternative to SNMP 
that treated object ID sequences more in tune with what OSI designed and 
ended up with an SNMP near replacement that was orders of magnitude 
faster, smaller, more secure, and more able to perform atomic control 
operations - https://www.iwl.com/idocs/knmp-overview )

But the OSI folks really shot themselves in the foot by:

    - Charging $$ just to see the specification documents, which were 
written in opaque language, and were designed to be all things to all 
people without any practical engineering to cut them down to 
implementable size and useful deployment.

    - Being all snooty and kinda unwilling to engage with other 
networking professionals - it was ITU/CCITT all the way and everyone 
else can go pound sand.  Our small company considered joining the OSI 
committees - but the entry fees were aimed at IBM sized companies, not 
the kind of small companies in the TCP/IP world.

    - Treating their designs as perfect and complete rather than as an 
evolving exploration of a new technology, store and forward packet 
switched networks.

I kinda like the TUBA - basically replacing IPv4 with OSI CLNP - 
proposals when we were in the early phases that led to IPv6 (I confess I 
was cued by Cindi Jung.)

By-the-way, Sue Hares built some really cool wooden rubber-band machine 
guns.  Not that this is relevant to anything, but it was fun.

         --karl--