I've recently set up an automatic failover from our main leased line connection to a backup ADSL one. When this happens our public IP address changes, and our Mitel 250 system is immediately unable to connect outside calls. A reboot of the system seems to fix the connection and allow the calls to go through, but once the connection switches back to the main leased line and the IP changes again it just loses connection again and requires another reboot.
We are using SIP trunks for our external calls.
Does anyone know if it's possible to prevent this and ensure it works seamlessly?