RE : RE : : Using DIAMETER_MISSING_AVP for optional AVP

Hi John,

I didn't say anything about "conditional" AVP ;-)

> > > My guess is that if a particular implementation or 
> application was 
> > > expecting an AVP to be included, this would be a 
> reasonable way to 
> > > do it.
> > > 
> > 
> > Based on this definition, it is only applicable to AVP "required by 
> > the command code definition". It is not clear if we could reuse the 
> > same result code for an optional AVP.
> 
> So, you were asking about Conditional AVPs.  There are no 
> such things as conditional AVPs in the base spec, that is why 
> they are not mentioned.
> 
> I am aware that there are some 'vendors' making Diameter 
> extensions to 
> introduce this kind of 'feature.'  I don't see why those 
> 'vendors' can't use DIAMETER_MISSING_AVP to mean a 
> conditional AVP as well.  

[LM] The problem is not restricted to conditional AVPs. Based on your
response, you could use DIAMETER_MISSING_AVP for any optional AVP, based
on specific service logic using a given Diameter application.

> 
> > If there is a general consensus on this topic, maybe a 
> modification to 
> > the existing definition should be done.
> 
> Why?  Diameter has no notion of conditional AVPs.

[LM] Because this would apply to any optional AVP used in the command
(whatever the use of this optional AVP).
 
> > Besides, if we could reuse the same result code for required or 
> > optional AVP, should we state that "a Failed-AVP AVP MUST 
> be included" 
> > instead of "should be included"?
> 
> What is your reasoning for this?
> 
> > My assumption was that a "SHOULD" was possible here because 
> you could 
> > have relyed on the command code ABNF descritpion to find 
> the missing 
> > AVP. If the above assupmtion is correct, it is not possible anymore 
> > and you have to use the Failed-AVP.
> 
> I'm sorry, could you restate what you mean, I am having a 
> hard time understanding your point.

[LM] If DIAMETER_MISSING_AVP can be used for any missing AVP (required
or optional), a Failed-AVP AVP MUST be included in the message, to
indicate to the originator of the request what is the missing AVP. If
DIAMETER_MISSING_AVP is used alone, the originator would not be able to
rely on the command code ABNF definition to find the missing AVP.

Thanks,

Lionel