I agree that there could be several possibilities for this problem, although in my opinion this problem it is not related with "Symmetric Nat" option and/or "Optimize Audio Path" option. I also agree that the provider customer assistance is not a "dream team", but in this specific case I believe that they gave me the right information, as long as it was only about the registration status (yes or not). On the other hand, an issue with the timers configuration is more likely. Server unresponsiveness is another possibility.
In the end, the point is that all possibilities are in the field of uncertainty because from ATA onwards everything is a cloud and there is no visibility for the users about what really happens between Voxalot and the provider. I believe this could improve if there were more information and certainness about provider registration status.
I also read the case
http://forum.voxalot.com/voxalot-sup...html#post15138 but the problem is not the same, because I did not receive any error message, instead the calls were diverted directly to the provider voice-mail (not Voxalot voice-mail) because of registration loss.
Thanks!