Subject: [NGO] Lessons learned from SMIng

From: David Partain <[email-masked]>
Date: Tue, 29 Jan 2008 19:37:43 +0100

Greetings,

I don't know if everyone is aware of the SMIng work that took place here at 
the IETF.  I think it's safe to say that it didn't go as well as we would 
have liked, for a variety of reasons.  

It might be instructive for those who haven't already done so to read 
draft-schoenw-sming-lessons-01.txt, which is Jürgen Schönwälder's take on 
what we should learn from our work on SMIng.

Since I don't want to speak for Jürgen, maybe he could chime in with a summary 
of what he thinks were the most important lessons?

Thanks.

David

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From: Juergen Schoenwaelder <[email-masked]>
Date: Tue, 29 Jan 2008 20:36:30 +0100

On Tue, Jan 29, 2008 at 07:37:43PM +0100, David Partain wrote:
 
> Since I don't want to speak for J?rgen, maybe he could chime in with
> a summary of what he thinks were the most important lessons?

One of the goals of the SMIng effort was to develop a protocol
independent network management data modeling language and it took us
years to figure out that this sounds nice on paper but leads to
various problems that make it extremely hard to write protocol
independent models.

Those who write requirements or data modeling languages evaluations
pushing for protocol independent languages instead of domain specific
languages are invited to read the lessons learned so that they can
prepare how they thing the issues raised in that document can be
answered without creating a language which is extremely difficult to
use due to the number of indirections required.

Let me also use this email to note that I do not understand the
evaluation of SMIng in table 2 in <draft-xiao-evaluate-dml-01.txt> on
page 13:

- Why is SMIng weak on protocol independence but MIF is strong?

- Why do the authors believe SMIng fails on naming independance?? I
  believe SMIng has naming system independence - the problem is that
  it is a pain to use.

- Why does SMIng fail on diversity of data types but SMI has weak
  support? The SMIng data type system is much more powerful than the
  SMI type system.

- Why does SMIng fail on extensibility of data types?

- I fail to understand why locking mechanisms and access control
  mechanisms are criteria for a comparison of data modeling languages.

Note that I am not pushing for SMIng - but I think it should be
treated fairly.

/js

PS: Note that SMIng was nice as long as we were doing toy examples. It
    failed once we started to do more complex data models. It is
    important to keep this in mind while looking at examples that fit
    nicely on slideware.

-- 
Juergen Schoenwaelder           Jacobs University Bremen gGmbH
Phone: +49 421 200 3587         Campus Ring 1, 28759 Bremen, Germany
Fax:   +49 421 200 3103         <http://www.jacobs-university.de/>

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From: "Bert Wijnen" <[email-masked]>
Date: Tue, 29 Jan 2008 20:50:11 +0100

> what we should learn from our work on SMIng.

Yes, I have read that draft (in fact I did review it closely) and I think
it is very good reading material for all who want to participate in the
CANMOD BOF.

Bert