Subject: RE: [AAA-WG]: Clarification on ABNF Command specification

From: Jacques Caron <[email-masked]>
Date: Wed, 25 Jul 2001 19:35:43 +0200

Hi,

A stupid suggestion: what about just putting AVPs in ascending numerical 
order, and assigning AVP codes in different ranges (e.g. 0x10000-0x1ffff 
for AVPs that must be at the beginning, 0x20000-0xfeffff for those anywhere 
in between, and 0xff0000-0xffffff for those that must be at the end)?

Of course, there's the issue of Radius codes [though they could be remapped 
to somewhere else than the 0-255 range, by prepending them with some known 
prefix], and of Vendor-specific AVP codes.

And also some AVPs might be fixed in some commands and not in others 
[though I guess those that must be at the start or at the end are 
presumably protocol-related rather than application-related?].

And honestly I'm less and less convinced about the whole ABNF thing. I 
would at least separate all the protocol-related AVPs (e.g. Route-Record, 
Source-Route...) from the command-code specific AVPs in some way. See also 
my comment about the additional accounting-application-specific AVPs in the 
same accounting messages as per 2.6 in a previous post...

Jacques.

At 19:10 25/07/01, Cain Brian-BCAIN1 wrote:

> > -----Original Message-----
> > From: Erik Guttman [mailto:[email-masked]]
>...
> > Right, though the required AVPs come before the optional ones
> > according
> > to the grammar.
>
>Okay, what about an AVP that shows up in required with, e.g. 0 as minimum 
>occurrences, and 5 as its maximum.  Now, this AVP can show up any place in 
>the required section, but must all of its occurrences be contiguous, or 
>can they be scattered throughout the required AVPs?
>
>Command format:
>
>      < A >
>  0*5 { B }
>      { Q }
>
>An Actual instance of the given Command:
>
>A
>B
>B
>B
>Q
>B
>
>This would be valid, or invalid, given the format above?
>
>I think the text "The AVP MUST be present" is slightly ambiguous.  Perhaps 
>"All occurrences of the AVP MUST be present in one contiguous block" or 
>"The occurrences of this AVP MUST show up anywhere within the required 
>section, potentially non-contiguously", depending on the answer.  Okay, 
>that doesn't quite flow that well, but someone could come up with an 
>equivalent, I imagine.
>
>-Brian

_________________________________________________________
Do You Yahoo!?
Get your free @yahoo.com address at http://mail.yahoo.com

---

From: Pat Calhoun <[email-masked]>
Date: Wed, 25 Jul 2001 12:15:44 -0700

> prefix], and of Vendor-specific AVP codes.

Why has ordering now become important? We decided a long time ago (WG
consensus, btw) that ordering was not important, with the exception of
the AVPs in < >.

> presumably protocol-related rather than application-related?].

The ONLY AVP that I know of that we require to have any ordering is
the Session-Id. This is merely for convenience to speed up the lookup
process of the session control block. We could have gotten rid of it 
some time back, but didn't.

> same accounting messages as per 2.6 in a previous post...

well, I have personally never seen WG consensus on this particular change
request, nor an issue. I also must admit that re-architecting the specs
for mere convenience is probably something that should have been done prior
to the imminent WG last call :(

PatC