Small office with 30 phones - we have a Cisco 5520 firewall configured to failover to a secondary ISP (Different Static IP) if we lose service, the failover happens in 2 seconds -- is there any way to keep phone calls alive if the outgoing IP address changes mid call?
In my testing the phone has a registration problem when the failover occurs
The internet has no issue when the failover happens - videos continue to stream, email works, etc.