@NguygieNguygie wrote: ↑Sep 5th, 2016 10:50 amSo I've tried your suggestions to no avail... I'm officially giving up on trying to make Fongo work with OOma. I downloaded the TextNow app to try and call home and voilà - it can call Ooma fine. So I'll just use TextNow to call home and Fongo for all my other calls. A bit annoying but can't complain too much with free calls. Thanks again for all your time and help.
This could be an issue with Ooma itself with respect to receiving calls from certain carriers. For example, click http://www.ooma.com/forums/viewtopic.php?f=4&t=5614. If the problem is a carrier issue with Ooma--an issue that's specific to receiving calls from numbers (possibly specific to your area code) owned by Fibernetics (Fongo's parent company)--then you are going to have to try to find a decent tech support rep at Ooma (by decent, I mean one who isn't completely stupid) and explain the problem.
You can verify the carrier by entering in your phone number here: https://www.twilio.com/lookup. You can verify which carrier owns Fongo's number by entering it here: https://www.twilio.com/lookup. Should say Fibernetics for Fongo numbers. You can also check your Ooma number.
At first glance, I thought it might be a SIP ALG issue or NAT router issue, but it does seem more likely to be a carrier/trunk issue, especially since I now know you're not the only one having this problem. And I suspect that issue is on Ooma's end.