About Custom AVPs

An attribute-value pair (AVP) is used to encapsulate protocol-specific information with usage monitoring supported by the MPE device. Diameter messages such as RAA, CCA, CCR, and RAR are supported by third-party AVP policy conditions. The supported outgoing Diameter messages set or remove third-party AVPs.
Note: The Diameter messages listed are examples only. There are many messages associated with Diameter.

You can create policy conditions to evaluate the presence of both standard (base) and third-party AVPs in Diameter messages or group AVPs during policy execution. A policy condition can check for the presence of both standard and third-party AVPs in incoming Diameter messages and evaluate their values. A policy action can use standard and third-party AVPs for routing, authentication, authorization, and accounting.

Standard AVPs can be included in third-party AVP conditions and actions. To include a standard (base) AVP in a nonstandard application message, or to use a pre-standard AVP as a standard AVP, define it as a custom AVP.

When defined, custom AVPs are located at the end of a parent Diameter message or group AVP. If the parent AVP is null, the custom AVP is inserted at the root level of the message. For example, a custom AVP definition appears at the end of this Charging-Rule-Install message:
 Charging-Rule-Install ::= < AVP Header: 1001 >
*[ Charging-Rule-Definition ]
*[ Charging-Rule-Name ]
*[ Charging-Rule-Base-Name ]
[ Bearer-Identifier ]
[ Rule-Activation-Time ]
[ Rule-Deactivation-Time ]
[ Resource-Allocation-Notification ]
[ Charging-Correlation-Indicator ]
*[ customAVP ]

A Set or Get SPR user attribute value can be set to the defined third-party AVP in Diameter messages. You can also set or remove defined third-party AVPs during the execution point.

A third-party AVP is identified by a unique identifier in the following format:
name:vendorId

For example:

Condition
where the request AVP NEW_AVP3:555 value is numerically equal to 2012
Parameters
The AVP name and vendor ID. In the example, the vendor ID is 555.
Description
A well-defined AVP custom name is referred to if the vendor ID is not specified.

When entering and sending a new third-party AVP definition to an MPE or MRA device, the definition must include the AVP name, code, vendor ID, data type, and an optional AVP flag.

Validation of the AVP code, Name, and vendor ID prohibits a user from overwriting the existing base AVPs.

These AVP actions include the ability to perform the following: