Topology - 7941 phone configured to use SIP - connected to a Linksys Switch which is connected to a IAD 2400 Series Router. All Phones register to a DNS Name called VOIP.XXXXXX.NET - This DNS correlates to our 2 Session Border Controllers. Call them SBC 1 and SBC 2.
When SBC 1 is online the phone functions without any issues. Place calls, receive calls, everything works flawlessly.
When we take SBC 1 offline to test redundancy and failover. The 7941 loses its registration and when I do a capture I only see the registration go out to VOIP.XXXXXXXX.NET but it is querying the IP address of SBC1 for the registration it never queries SBC2's IP Address for the registration. I have added the IP Address of SBC 2 in the Backup Proxy, Emergency Proxy everywhere in the config but when I take SBC1 online it never queries the IP of SBC2. I am at a dead end. PLEASE HELP I'M LOSING MY MIND TRYING TO FIGURE OUT THIS ISSUE.