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From: ast@cs.vu.nl (Andy Tanenbaum)
Newsgroups: comp.dcom.lans,comp.protocols.misc
Subject: Re: OSI-model software
Message-ID: <1436@botter.cs.vu.nl>
Date: Wed, 24-Jun-87 08:03:52 EDT
Article-I.D.: botter.1436
Posted: Wed Jun 24 08:03:52 1987
Date-Received: Sat, 27-Jun-87 00:50:57 EDT
References: <223@diab.UUCP> <233@idacrd.UUCP> <526@alliant.UUCP> <1214@botter.cs.vu.nl> <4122@amd.UUCP>
Reply-To: ast@cs.vu.nl (Andy Tanenbaum)
Organization: VU Informatica, Amsterdam
Lines: 32
Xref: mnetor comp.dcom.lans:585 comp.protocols.misc:100

In article <4122@amd.UUCP> nguyen@amd.UUCP (Quinn Nguyen) writes:
>In article <1214@botter.cs.vu.nl>, ast@cs.vu.nl (Andy Tanenbaum) writes:
>> I think the session layer is ridiculous.  
>
> Quinn then goes on to say:
>Some one [who] proved that the session layer is
>not null (such as IBM) must have a very good reason for it! 

This is the kind of thinking that led to OSI in the first place.  The
committee observed.
   1.  IBM has a 7 layer network architecture.
   2.  IBM is big and powerful and successful

Ergo, if we have a 7 layer network architecture we will become big and
powerful and sucessful.  Nonsense.  It is not desirable to create a giant,
ponderous beast that lusts after megabytes the way the cookie monster
goes after cookies.  St. Exupery said: Perfection is not achieved when
there is nothing left to add, but when there is nothing left to take away.

Look at the success of RISC machines.  Computer architects have learned that
what one does NOT need is an unwieldy instruction set that no compiler
can produce code for.  Adding more instructions and modes and stuff on the
off chance that someone will someday need it is foolish.  The idea of
having a session layer for those few applications that can't keep track
of whose turn it is to talk is equally silly.  Let them do it as part of
the application.  I think network architectures (and everything else in
the world) should be made as simple as possible, consistent with their
intended goal.  I think OSI needs to go on a crash diet.  Null session
layers aren't the way to go.  The structural complexity is still there, 
even if it is dormant for the moment.

Andy Tanenbaum