Hello, Originally the issue was reported to International Russian forum but 3CX person (archie) recommended to leave bug report there. The issue: There is incoming trunk from Sipnet.ru. This trunk works perfect. CallerID is working from PSTN. There is second trunk to external IVR. For connection to external IVR we need to send INVITE without authorization to dedicated IP. It doesn't ask authorization and doesn't request authorization. Need to send Invite with CallerID and CalledID to dedicated IP. I created outgoing trunk to this IP. I had to put AuthID and External Number because it is mandatory. It was random value. Next I configured Provider Outbound Parameters: Contact: User Part - CallerNum From user: -CallerNum Next I routed incoming trunk from PSTN to 'Forward to Outside Number. And routed this Outside Number to outgoing trunk to IVR. The calls is going. Voice is going. But IVR gets CallerID as AuthID on outgoing trunk. We discussed this question with Archie and it looks as bug. I checked this via Wireshark. 3CX sends ALWAYS CallerID to outgoing trunk - AuthID which I configured for outgoing trunk. Advanced Settings don't work. Could you look? Thanks so much.