Custom Provider Template Issues / Trunk Issues

[SenecoGroup]

Hi team,

We are troubleshooting custom SIP From header rewriting in 3CX V20 Update 9 with an Aussie Broadband (NetSapiens) SIP trunk.

Goal:
We need the outbound SIP From header formatted as:

sip:&lt;DID&gt;@AUTHID:5060<br>
However, 3CX keeps rewriting it to:

sip:&lt;DID&gt;@sip.provider.com:5060<br>
Environment:

• 3CX V20 Update 9 (Build 20.0.9.946)
• Custom provider template
• UDP transport
• ABB / NetSapiens SIP trunk

Current XML being tested:

&lt;field name="ParameterOut" custom="AUTHID:5060" parameter="FromHostPart"&gt;$CustomField&lt;/field&gt;<br>
Important findings:

• $CustomField DOES send the INVITE successfully
• 3CX does NOT reject the call internally
• The carrier replies with 403 Forbidden
• Packet capture shows 3CX is still rewriting the FromHostPart
• Instead of using the custom value, 3CX replaces it with the provider proxy/gateway hostname

Example result seen in PCAP:

From: sip:[email protected]:5060<br>
Expected:

From: sip:&lt;DID&gt;@AUTHID:5060<br>
We also tested:

&lt;field name="ParameterOut" custom="AUTHID:5060" parameter="FromHostPart"&gt;$GWHostPort&lt;/field&gt;<br>
but V20 appears to ignore custom="" completely when $GWHostPort is selected.

Questions:

1. In V20 U9, is FromHostPart now normalised/rebuilt after template substitution?
2. Is there an internal SIP validation or canonicalisation process overriding custom host values?
3. Has anyone successfully forced a literal custom FromHostPart value in V20 U9?
4. Is there another SIP field now used internally instead of FromHostPart?
5. Does 3CX now force the From domain to match the provider proxy/registrar?

We installed a NEW self hosted 3CX install, which after that is when I noticed the problem, being that we are being blocked from customising our outbound DID's. I assume because the header is not built as ABB expects it, it's being defaulted back to the primary trunk number. I have tried to update and it has given me more options to trouble shoot but to no avail, observed all the PCAP I could handle.

Our second and primary host is on Version 20.0.8.1121 (last version that I observed this working)

 

[YiannisH_3CX]

If the parameter is misconfigured then 3CX will default back to the default value since From header is mandatory.

I just tried your scenario on Update 9 and it works fine for me.

 

[SenecoGroup]

Thanks, I have tried this and the FROM header is now displaying correctly.

I am confirming with my provider if the issue is now on their side as the calls now have a 403 Forbidden on anything outbound.

 

[SenecoGroup]

It's really strange - I am still troubleshooting this on and off.

When I change the FromHostPart to CustomField then it does change the From header correctly, but the calls are then 403 forbidden. I can't seem to understand why but it is specifically that line in the template that breaks it.

I am still talking to ABB but not sure if they will have an answer for me.

 

[N_G]

That is why you use a supported voip provider