Re: smilint remembers named number in OID value assignment (fwd)

["Randy Presuhn" <randy_presuhn@mindspring.com>]

Hi -

> From: "C. M. Heard" <heard@pobox.com>
> To: <ietfmibs@ops.ietf.org>
> Sent: Monday, November 29, 2004 12:55 PM
> Subject: Re: smilint remembers named number in OID value assignment (fwd)


...
> >      dot3MauType OBJECT IDENTIFIER ::= { mib-2 snmpDot3MauMgt(26) 4 }
> >
> > and as a result complains about the second one (see attached e-mail
> > robot output).
> >
> > As I understand it, the names associated with these "named number"
> > constructions are supposed to be local to the OID assignment and not
> > known outside that scope -- at least that's how it works in ASN.1,
> > from which these constructs were inherited.  In effect, the name
> > attached to the number in these constructs is nothing more than a
> > comment.
>
> Frankly, I do not really know what the rule is here. If the name is
> truely local to the assignment, then it has no purpose at all since
> you hardly can reference the name. Obviously, libsmi does not treat
> this as purely local. I guess the best thing would be to raise this
> question on the mibs mailing list to see whether there is concensus
> how this is actually supposed to work.
...

The identifier in the "NameAndNumberForm" (as X.680 refers to it) can't
be re-used without the number, unless it is one of the ones defined in X.660.
These identifiers are only of documentation value, and there is certainly
nothing for a compiler to complain about if the same identifier appears
with the same number more than once in a module.  If it appeared in
the same position with different numerical values, it might be good for
a compiler to generate a warning.  Likewise if different identifiers were
used with the same numeric value in the same position.  But, as I read
ASN.1, this is not of itself an error.

Randy