Re: SMIv2

Randy Presuhn <rpresuhn@peer.com> Mon, 07 April 1997 11:48 UTC

Date: Sat, 05 Apr 1997 15:21:34 -0800
From: Randy Presuhn <rpresuhn@peer.com>
Message-Id: <199704052321.AA041732494@dorothy.peer.com>
To: snmp2@tis.com
Subject: Re: SMIv2
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Hi -

> From: ppsdsm@ulb.ac.be (Pedro Palma Santos Silva Mendes)
> Message-Id: <199704051919.VAA14137@orca.vub.ac.be>
> Subject: SMIv2
> To: snmp2@tis.com
> Date: Sat, 5 Apr 1997 21:19:57 +0200 (DST)
> Sender: owner-snmpv2@ex.tis.com
...
> In the RFC 1902, in page 7 there two types are used: IndexObject and
> EntryObject. They are not defined in the RFC. What do they mean ?
> 
> I don't understand the meaning of: value(IndexObject ObjectName)
> because in the definition of ASN.1's Macros we can't have a type
> where IndexObject is. 
...

Those aren't types.  They are local value reference.  See clauses
A.3.9 and A.3.16 in Rec. X.208 (ISO 8824) where the grammar for
"value(localvaluereference MacroType)" is spelled out, and the
example in Rec. X.208 Appendix I clause I.3

A more fundamental point is this: the macro expansions for the
productions in RFC 1902 really aren't terribly meaningful.
The macro definitions are helpful as syntax guides for the
MIB compiler writer, but the literal ASN.1 semantics of these
productions are another matter.

It's analogous to the difference between an ASN.1:1994 information
object and a GDMO class.  From the perspective of a MIB compiler
author, concise MIB definitions are much more like the latter
than the former.  (One can start out just looking at the syntax,
but the interesting stuff is in the semantics.)

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 Randy Presuhn            BMC Software, Inc. (Silicon Valley Division)
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 In accordance with the BMC Communications Systems Use and Security
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SMIv2 Pedro Palma Santos Silva Mendes
Re: SMIv2 Randy Presuhn