"On Hook" but can't make a call?

[logicaloctopus]

I set up 3CX on my Samsung Galaxy (I9100M) with Android 2.3.3.
After setting up my profile to use an external SIP provider (iptel.org) I get the promising "On Hook" status.
But when I dial a number it says "Calling" for about 2 or 3 seconds and then just goes back to the "On Hook" status without completeing the call.
Did I miss something in the setup. What do I need to do to complete a call? Thanks.

 

[leejor]

The phone may be trying to complete the call. One or more of your settings, or the network, may be preventing it from going through. It may also be possible that the call is being rejected by your provider. You may be able to get some help from them in determining if they are seeing correct information when you attempt a call. short of that, and if you are using WiFi on your home network, you may be able to troubleshoot it using a tool such as Wireshark.