Different P-Asserted Number (PAI) to that of the CID

Hi All,

Currently we have FreePBX setup to add the PAI header in SIP. This is enabled by adding the following to the outbound settings of the trunk


When doing the wireshark (TCPDUMP) trace it is currently inserting the CID of the extension (number) into the PAI header as well which is fine normally

However for regulatory reasons we need to force a number in the PAI header which may be different to that of the extension for that one trunk.

Some extensions DONT have a CID (well their CID is ‘Withheld’), however for legal reasons we need to still send the office number in the PAI header so it can be tracked back to us or if that extension dials emergency services.

Our end result in the headers of a PCAP/WIRESHARK dump needs to be:

From: “WITHHELD” <SIP:[email protected]
P-Asserted-Itentity: “443303XXXXXX” <SIP: [email protected]

Currently on a withheld CID its:
From: “WITHHELD” <SIP:[email protected]
P-Asserted-Itentity: “SIP:WITHHELD” <SIP: SIP:[email protected]

I use extensions_override_freepbx.conf and the following to set my PAI:

exten => s,1,NoOp(Adding P-Asserted-Identity)
exten => s,n,SipAddHeader(P-Asserted-Identity: sip:[email protected] )
exten => s,n(done),MacroExit()

It gets called before the Dial(), so it should be included with every call.

How do you get to that file “extentions_override_freepbx.conf”? Is this under the GUI or in the console program?