Since the back end of last year when BT applied some changes to conform with OFCOM’s GC C6 we have noticed outbound calls from FreePBX where the caller ID is hidden in the outbound route now get rejected with a 603 error. I believe the issue is because there is no P asserted identity being sent from the FreePBX. Is there an easy way to resolve this in the GUI?
I was just working on something like this yesterday, and ended up with this custom dialplan. Maybe you can edit it to suit.
[macro-dialout-trunk-predial-hook]
exten => s,1,Noop(Entering user defined context macro-dialout-trunk-predial-hook in extensions_custom.conf)
exten => s,n,GosubIf($["${TRUNKOUTCID}"="hidden"]?anonymize-outbound-call,s,1) ; enable hide CID in trunk config
exten => s,n,MacroExit
[anonymize-outbound-call]
exten => s,1,Noop(Entering user defined context anonymize-outbound-call in extensions_custom.conf)
; in order to prevent 2 PAI headers, it's important to DISABLE PAI on the trunk config in the GUI
exten => s,n,GoSub(func-set-sipheader,s,1(P-Asserted-Identity,<sip:${DIAL_NUMBER}@domain>))
exten => s,n,GoSub(func-set-sipheader,s,1(Privacy,id))
exten => s,n,Set(CALLERID(number)=Anonymous)
exten => s,n,Set(CALLERID(name)=Anonymous)
exten => s,n,Return