"Trouble is it doesn't work"....
I can see from the info page that the PSTN Line has placed a VoIP call to
xxxxxx@au.voxalot.com, but to the PSTN caller the line just keeps on ringing and is eventually answered by Telstra voicemail.
I have used Gizmo to test a SIP call to
xxxxxx@au.voxalot.com and this goes immediately to voicemail, so the address appears to be valid. This occurs despite the fact that my ATA is registered to this account.
Hope this helps.