OK, good to see that now that your ATA is successfully registered with voxalot that you can receive calls.
The fact that it rings a couple of times and then cuts out is nearly always a voicemail setting. As Emoci suggested, it is usually best to turn off voicemail while you're doing diagnostics.
In any case, I took the liberty of checking your voicemail settings, and noticed that the timeout has been set to 5 seconds. If you go to the
voicemail page and set it to 30 seconds, does that help?
--
Craig