Diameter value decode for AF-Application-Identifier and AF-Charging-Identifier

Question

Greetings,

Is there a way to correct decoded value for AF-Application-Identifier and AF-Charging-Identifier AVP's to show printable text / correct decode?

Current version Wire shark displays:

AVP: AF-Application-Identifier(504) l=72 f=VM- vnd=TGPP val=2b672e336770702e696373692d7265663d2275726e253341...

Printable text: +g.3gpp.icsi-ref="urn%3Aurn-7%3A3gpp-service.ims.icsi.mmtel"

AVP: AF-Charging-Identifier(505) l=69 f=VM- vnd=TGPP val=6f326c6a69317362673230302d70637363662e6c61622e69...

Printable Text o2lji1sbg200-pcscf.lab.ims.optus.com.au-1424-62704-257574

Accepted Answer

According to 3GPP specifications

6.5.5 AF-Application-Identifier AVP
The AF-Application-identifier AVP (AVP code 504) is of type OctetString,
and it contains information that identifies the particular service that the AF service session belongs to. This information may be used by the PDF to differentiate QoS for different application services. For example the AF-Application-Identifier may be used as additional information together with the Media-Type AVP when the QoS class for the bearer authorization at the Go interface is selected. The AF-Application-Identifier may be used also to complete the QoS authorization with application specific default settings in the PDF if the AF does not provide full Session-Component-Description information.
6.5.6 AF-Charging-Identifier AVP
The AF-Charging-Identifier AVP (AVP code 505) is of type OctetString,
contains the AF Charging Identifier that is sent by the AF. This information may be used for charging correlation with bearer layer.

So there’s no guarantee that the AVPs will contain printable test so in that respect Wiresharks presentation is correct.

If you want to change that you would have to add code to packet-diameter_3gpp.c to check if the content is prinatble text and if so add it to the protocol tree. see

dissect_diameter_3gpp_visited_nw_id().