Just downloaded and set up 3CX V15 on win 10. Used PIAF in past. Set up fine. Some trouble with cable internet provider (Northland Cable). Firewall test passes until port 9020 and above. Then reports full cone failed above port 9019. Using Vitelity. Trunk registers fine. Extensions set up and can communicate from extension to extension and to digital receptionist. But no incoming or outgoing calls. Outbound call gets fast busy signal. Call log says no answer. Event log shows nothing. Any suggestions would be greatly appreciated.