What precludes a VoIP provider from being proactive when a subscriber's ATA has not re-registered for x amount of time?
My ATA (a Grandstream) has run for a long time with the same router here, same configuration, etc. Suddenly, I get fast busy on call attempts. This may mean that the ATA is not in session with the server.

My expectation:
VoIPo has ATAs arranged to re-register every x hours. The default arrangment should be for VoIPo to note overdue re-registrations and take action, be that an automated email/SMS or a phone call to the backup number, etc.

Instead, apparently no action is taken, per the rather lame response from support. According to my router, my internet connection has been "up" for 20 days. And my PCs have had no glitches. No DHCP faults.