Passing P-Asserted-Identity from Softphone to Outbound Trunk From Header

[Axio]

Hi everyone,

I am trying to configure VitalPBX so that when a softphone sends an outbound INVITE containing a P-Asserted-Identity (PAI) header, VitalPBX reads this header and uses its value as the Caller ID in the From header sent to our outbound PJSIP trunk.

Current Scenario:

· Softphone sends an outbound INVITE with: P-Asserted-Identity: <sip:[email protected]>

· Goal: Extract the data and use it as the From header user when making the outbound call over the PJSIP trunk.

What was tested:

1. Set extension Dynamic External CID to YES.

2. Set trunk Trust ID Inbound to YES

Questions for the community:

· What is the recommended practice in VitalPBX to extract an incoming softphone PAI header and pass it to the outbound trunk From field?

Any examples or best-practice recommendations would be greatly appreciated!

Thanks!

[TELECOMIN]

Hi,

Please try by enabling Send P-Asserted-Identity under Device profile and enable Trust ID Outbound alongside Trust ID Inbound under outbound trunk.

[Axio]

Hello, thank you, but it is still not working.

Here is what the device is sending to VitalPBX:

And here is what VitalPBX is sending to the trunk:

It seems like VitalPBX is not taking the PAI into account. Has anyone managed to successfully achieve what I’m trying to do?

[mo10]

Does this help you?

CUSTOM P-Preferred-Identity

I need to input the P-Preferred-Identity: sip:[email protected];user=phone;AAA5XSHNBBB os sip header of outgoing call from vital extension to public sip provider. I already try to add file: root@pbx:/etc/asterisk/vitalpbx# cat extensions__50-custom_ppi.conf [custom-add-ppi-header] exten => _X.,1,NoOp(Adicionando P-Preferred-Identity para ${EXTEN}) exten => _X.,n,SIPAddHeader(P-Preferred-Identity: sip:[email protected];user=phone;AAA5XSHNBBB) exten => _X.…

[Axio]

Hi mo10, I did see that post, but it doesn’t really apply to my use case. It seems overcomplicated for something so many people actually need. I’m not sure if this is a bug or just designed this way.

[miguel]

Why the Sofphone is not sending that information in the Caller ID headers. The Dynamic External CID only works when the caller sends a Caller ID value that needs to be pass to the destination.

[Axio]

Hello,

We are using a few different PBX systems, and we can’t simply map or overwrite the From header using the PAI (P-Asserted-Identity) value because it causes authentication failures on outbound INVITE packets from the PBX side.

The softphone constructs its From header using its SIP authentication credentials—which is standard behavior, as a registered SIP client’s From header must match the AOR used for authentication—rather than the caller ID/display number you wish to present.

This is precisely why rewriting the outbound From header based on the PAI makes sense: if the softphone sends a valid identity via P-Asserted-Identity alongside its technical From header, that is the value the PBX should extract and use for outbound caller ID.

Unless I’m mistaken?