General: Make A Friendly name
All default
Termination:
SIP URI, Make it the same as friendly name
IP Access Controil List: Friendly name CIDR Network address, use a calculator. IP access control list name can be the IP address itself. IP Access control should be the same as your PBX server
Origination
SIP URI: sip:yourdomain.3cx.us
Enable CNAME lookup: See what this is. It cost some more money
Disaster Recover: Can be set up if mission critical
Numbers: Multiple numbers can be set to a trunk. DID can go to a specific extension