Path: utzoo!utgpu!water!watmath!clyde!cbosgd!ihnp4!ptsfa!lll-tis!lll-lcc!rutgers!bellcore!faline!karn
From: karn@faline.bellcore.com (Phil R. Karn)
Newsgroups: comp.protocols.tcp-ip
Subject: Re: Much More Idle Chatter About Reference Models
Summary: Fundamental problems with reference models
Message-ID: <1642@faline.bellcore.com>
Date: 19 Dec 87 06:10:20 GMT
References: <12359521472.59.STEVENS@A.ISI.EDU>
Organization: Bell Communications Research, Inc
Lines: 18

I think the reason there is so much argument about where things like network
management protocols and packet radio protocols "go" in the ISO/OSI
reference model is that the OSI reference model itself is fundamentally
flawed. Face it, the OSI reference model is over a decade old, and even then
it was inadequate to describe real working networks. (As opposed to, say,
the paper networks ISO is *still* building...)

What's far more important is the relationship between the various protocol
modules (i.e., who runs "on top of" who), not which arbitrary "layers" they
"belong" to. See Postel and Cohen's paper "The ISO Reference Model and Other
Protocol Architectures" for an iron-clad proof that N = N+1 for 1 <= N <= 7,
according to the ISO model.

My math professors used to tell me that when you get a result like this
and you haven't made an error in your logic, then your fundamental
assumptions must be wrong...

Phil