Extension AVPs

The binary CDR format contains Diameter AVPs encoded in binary form, and the List CDRs tool decodes these binary AVPs before printing them in a human readable format.

The tool has built-in knowledge of AVPs which are defined in Diameter protocols such as Rf and Ro.

It can also be customized with knowledge of user defined extension AVPs, by providing definitions of those AVPs in YAML files.

The List CDRs tool looks in the list-cdrs/extension-avps directory for YAML based files which define these extension AVPs.

A default installation of the List CDRs tool contains a DiameterExtension-AVP.yaml file inside this directory, which defines OpenCloud’s extension AVPs. This means that by default, the List CDRs tool recognizes all the AVPs in the CDR files produced by Sentinel.

When encountering an AVP which it does not recognize, the List CDRs tool treats it as an Undefined AVP. Because the tool can’t see which type of AVP it is (e.g. UTF8String or Integer32), it prints the raw binary content of the AVP in hexadecimal format.

This is how the List CDRs tool will print an extension AVP that it doesn’t recognize:

This is how the List CDRs tool prints that same extension AVP, when that AVP is configured as an extension AVP (see below):

This is an excerpt from the default extension AVP configuration file at
list-cdrs/extension-avps/DiameterExtension-AVP.yaml, showing the first two extension AVPs:

To configure your own custom AVP, add a new file with the same opening structure as extension-avps/DiameterExtension-AVP.yaml, but with your own extensions.

An example configuration file:

After you have created such a file you will also have to add the AVP names to the Charging profile in the DiameterExtensions profile table, which lives in the file extension-avps/DiameterExtensions.yaml. The profile consists of an array that lists all of the desired AVPs in the format <profile table name>/<profile name>. So for the two AVPs from the example above you would have to add these two lines to the Charging profile:

Note that the profile to use for the supported extension AVP list is configured with the ExtensionAvpSet property of the Diameter RA. See Configuring Extension AVPs for the full documentation of these profile tables.

The required fields for each AVP: