Dear All, I have an issue with calls to be placed from extension over the internet. The extension is registered properly and also receives incoming calls from the PBX. However, when extensions tries to place a call (equal internally or externally) a classical " Unidentified incoming call. Review INVITE and adjust source identification" is logged and the call is rejected as from unknown source. The only difference to "usual" extensions I see, is that under "Phones" section under column IP is written FQDN of the extension's IP, and not an IP address (correctly resolved). Therefore my question is - how 3CX (v15 if means) match call from extension and registed contact? might the FQDN and not IP under "Phones" section be a reason, that call form the extensions is not considered by 3CX as a call from extension? BTW: The same extension without any change works on Asterisk PBX without any issue.