Re: comments on draft-ietf-sming-reqs-02.txt: Reusable vs. Implemented definitions (was concrete vs. abstract)

[Juergen Schoenwaelder <schoenw@ibr.cs.tu-bs.de>]

>>>>> David Harrington writes:

David> I don't feel that the need for abstract structures has been
David> demonstrated, and we have no operational experience of the use
David> of abstract structures in either SMI or SPPI.

The SMIv2 does not have reusable "attribute groupings" and thus 
every definition of concrete and not abstract. I think there is an
accepted requirement that we need reusable "attribute groupings"
- so I am not sure what you are arguing here.

David> No examples are given in this document, and I fear that there
David> may be assumptions made about how abstract structures would be
David> used that are not clearly identified here.  Before this is made
David> a requirement, I think there needs to be serious discussion
David> about the possible uses to which they would be put, and how
David> that might impact the language and the protocols that would use
David> them.

With reusable "attribute groupings", some of them will exist just to
be reused (e.g. a five tuple filter) while others will exist to be
instantiated (an ifEntry). (In fact, I believe it is more important to
flag those "attribute groupings" that are "final" in the sense that
they will be instantiated in protocol mappings - but that is probably
part of a solutions discussion.)

I believe we need to distinguish between these two categories of
"attribute groupings" in the language.

/js

-- 
Juergen Schoenwaelder      Technical University Braunschweig
<schoenw@ibr.cs.tu-bs.de>  Dept. Operating Systems & Computer Networks
Phone: +49 531 391 3289    Bueltenweg 74/75, 38106 Braunschweig, Germany
Fax:   +49 531 391 5936    <URL:http://www.ibr.cs.tu-bs.de/~schoenw/>