We have a client that has two Mitel 3300's one at each of their two locations. The primary controller is at Site A with the Voicemail server. The secondary server is at Site B and sends its traffic via IPsec tunnel to Site A. Over the last few months we have had the Controller at Site B randomly drop for exactly 10 or 20 minutes. We get an error of "IP Trunk link to icp 001 "Site A" failed and link dropped" then after the 10 or 20 minute mark it returns to service.
When these drops happen, we are unable to ping the firewall from the Site B controller. However we can ping everything else on Site B. We ran traffic tests across the tunnel and all other devices at Site B can reach Site A and vice versa. Since this appears to be only an issue between the controller and the gateway (firewall), we had Fortigate support review our settings and they made some suggestions, but nothing has worked. It does not drop the same time every day and some times will go a few days without dropping. However, it always lasts for 10 or 20 minutes.
I am newer to these Mitel systems, so if anyone has any suggestions on where to look next it would be greatly appreciated.
Thank you!
