RE: Closing on NIM requirements

["Andrea Westerinen" <andreawest@mindspring.com>]

"What are we trying to model?"
>From the NIM draft, "modeling of network management constructs".  However,
the NIM draft addresses the requirements of the info model, not the extent
of the model.  This is a decision of the info modeling team once we have
established "how" we will model.

It seems a "bad thing" to have unrelated data models in DHCP, QoS, IPSec,
etc. when the basic entities being modeled all run on the same network.  The
goal of the info model is to describe and fit the network management pieces
together.  What "pieces" are worked is the decision of the work group, if
one is formed.

"Can we get it on a 24x80 screen?"
I tried to describe the problem above.  Could I make a "network management"
requirements document fit on a 24x80 screen?  I do not believe so - unless
it is a bad requirements document, lacking in details.

"Policy has been trying to recover ere since."
Do you have specific design issues that you would change in the policy
model/PCIM?  If so, then they should be raised and addressed.  If not, then
I think that the policy team "recovered".

I know that CIM seems difficult and complex - any wide ranging, object model
is.  Each of the enterprise management consoles has their own proprietary
object model to organize and correlate data.  If people pay tens of millions
of dollars for enterprise management, I would not think that it was easy.
The point of CIM is to provide a model into which a vendor can
"fit"/instantiate their pieces.  Relationships can tie the pieces together.

I do agree that CIM should be simplified (which I am actively working to
bring a proposal forward to the DMTF).  However, the basic constructs and
thinking behind CIM are reasonable. Perhaps some details are flawed, but I
do not know of one design that was perfect in its first iteration.

Given that I designed a large part of CIM V2.0 and 2.1, I would be happy to
argue the reasons behind the choices.  If the reasons are bad (in general or
in a network specific context), then I would NOT advocate making them again
:-).  However, I think that many of the designs have had alot of scrutiny
and would "hold up".

Andrea

> -----Original Message-----
> From: owner-nim@ops.ietf.org [mailto:owner-nim@ops.ietf.org]On Behalf Of
> Randy Bush
> Sent: Monday, April 17, 2000 11:36 PM
> To: Andrea Westerinen
> Cc: nim@ops.ietf.org
> Subject: RE: Closing on NIM requirements
>
>
> > The data/relationships/methods must be modeled enough, but not too much.
> > So, I always start with the problems being solved
> (requirements), and move
> > to the nouns and verbs.  I never start with a predefined model in mind.
>
> well, policy framework started with cim handed down from dmtf,
> and has been
> trying to recover 'ere since.
>
> so, what are the requirements here?  for what purpose(s) are we trying to
> model what?  can we get it on one 24x80 screen?
>
> randy
>