This happened all of a sudden yesterday. Not sure what change or problem occured but I'm looking for some help...
Central Office to Remote Office is a site to site VPN using SonicWall TZ/NSA products. DHCP is handed out at the RO by the SonicWall, the VoIP phones normally get DHCP, register to the call manager at the CO and everything works as expected. Suddenly, we have issues with 3 of our remote sites where the VoIP phones no longer connect to call manager, they just hang at "Registering...".
I've set up a test environment and sure enough, the same thing happens. If I hook up a Cisco 7975 to this test network, it sits at Registering..., however if I plug the phone in the CO lan, it works perfectly fine.
We had some auto-registering problems recently, but I'm not sure this could be the cause.
Just some notes...
-Both networks are pingable from opposite sides of the VPN, including the TFTP server/Call Manager
-I've restarted the TFTP servers on the Call Manager which didn't help at all
Is there anything fundamental to check regarding communications? DHCP is working correctly/the same as it always has.