For info only. I followed the steps in the document at http://www.voipvoip.com/3cx/ Outbound calls worked but I could not receive calls on my two trunks. Tried the following settings from VoipVoip tech support, with no luck: "Please go to Settings->Networks->STUN Server and make sure that the "Turn off stun server" box is ticked. If the box is ticked and the problem continue, please go to Settings->Network->Ports and change the SIP Port to 5466. Finally please make sure that the Enable Keep Alives box under Setting->General->Global Options is ticked. Sincerely, VoIPVoIP Customer Care" So I reset everything back to the settings before the VoipVoip suggestions and started testing. The resolution was to going into the advance tab of each voip provider and change the default registration from no registration to register inbound and outbound calls. That was it and inbound calls on the 2 voipvoip trunks work just fine. I reported the resolution to voipvoip tech support. Hope this helps someone.