RE: : Using DIAMETER_MISSING_AVP for optional AVP

Hi Lionel,

> In the RFC 3588, the result-code DIAMETER_MISSING_AVP is ussed to indicate that a mandatory AVP 
> (required by the command code ABNF specification) is missing in the received command.
> 
> Is it possible to use the DIAMETER_MISSING_AVP result code along with the Failed-AVP AVP to indicate 
> that an optional AVP (from the ABNF point of view) is missing in the received command? If not, could 
> you identify some operational issues?


From 3588:

   DIAMETER_MISSING_AVP               5005
      The request did not contain an AVP that is required by the Command
      Code definition.  If this value is sent in the Result-Code AVP, a
      Failed-AVP AVP SHOULD be included in the message.  The Failed-AVP
      AVP MUST contain an example of the missing AVP complete with the
      Vendor-Id if applicable.  The value field of the missing AVP
      should be of correct minimum length and contain zeroes.

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.

John