V20 Update 9 - Unable to append URI parameter to From header on Generic Registration SIP Trunk

[Sean A]

Hi everyone,


I'm working on integrating a custom SIP provider using a Generic Registration SIP trunk.


Environment

• 3CX Version 20 Update 9 (Build 995)
• Generic Registration SIP Trunk
• TLS transport
• Registration succeeds
• Inbound calls work
• Outbound calls are established

The provider requires the outbound INVITE to include a URI parameter in the From header.

Expected

From: "DID" <sip:[email protected];transport=TLS;otg=TRUNK_ID>;tag=...

Actual
From: "DID" <sip:[email protected];transport=TLS>;tag=...
The provider has confirmed that the missing otg= parameter is required and is the only remaining issue.

I modified the provider template as follows:


<field name="ParameterOut"
parameter="FromHostPart"
custom="provider.domain;otg=TRUNK_ID">
$CustomField
</field>



The template imports successfully, and the trunk continues to register normally, but the outbound INVITE still does not include the otg= parameter.


The provider captured the outbound INVITE from 3CX, and it still contains,


INVITE sip:[email protected] SIP/2.0


From: "DID" <sip:[email protected];transport=TLS>;tag=...
User-Agent: 3CXPhoneSystem 20.0.9.995 (995)
There is no otg= parameter present.

Question​

Is ParameterOut="FromHostPart" ignored for outbound INVITEs in V20?


Is there another supported XML parameter that allows appending URI parameters to the From header, or is this currently not supported by the 3CX SIP stack?


Any advice would be greatly appreciated.


Thanks!

 

[paulodagraca]

Hello Sean A,

This option "otg=TRUNK_ID" is used by systems like Cisco Webex.
It is covered by SIP URI parameter as per RFC3261 (That is what AI does think anyways).

There is no option to change this in the XML, and the "FromHostPart" is cleaned as should be, so not possible to add this youself.
Therefor it seems this is not possible.

Paulo