7.5. Failed-AVP AVP

7.5. Failed-AVP AVP

The Failed-AVP AVP (AVP Code 279) is of type Grouped and provides debugging information in cases where a request is rejected or not fully processed due to erroneous information in a specific AVP. The value of the Result-Code AVP will provide information on the reason for the Failed-AVP AVP. A Diameter answer message SHOULD contain an instance of the Failed-AVP AVP that corresponds to the error indicated by the Result-Code AVP. For practical purposes, this Failed-AVP would typically refer to the first AVP processing error that a Diameter node encounters.

The possible reasons for this AVP are the presence of an improperly constructed AVP, an unsupported or unrecognized AVP, an invalid AVP value, the omission of a required AVP, the presence of an explicitly excluded AVP (see tables in Section 10) or the presence of two or more occurrences of an AVP that is restricted to 0, 1, or 0-1 occurrences.

A Diameter message SHOULD contain one Failed-AVP AVP, containing the entire AVP that could not be processed successfully. If the failure reason is omission of a required AVP, an AVP with the missing AVP code, the missing Vendor-Id, and a zero-filled payload of the minimum required length for the omitted AVP will be added. If the failure reason is an invalid AVP length where the reported length is less than the minimum AVP header length or greater than the reported message length, a copy of the offending AVP header and a zero-filled payload of the minimum required length SHOULD be added.

In the case where the offending AVP is embedded within a Grouped AVP, the Failed-AVP MAY contain the grouped AVP, which in turn contains the single offending AVP. The same method MAY be employed if the grouped AVP itself is embedded in yet another grouped AVP and so on. In this case, the Failed-AVP MAY contain the grouped AVP hierarchy up to the single offending AVP. This enables the recipient to detect the location of the offending AVP when embedded in a group.

AVP Format

 ::= < AVP Header: 279 >
 1* {AVP}