Incoming calls on an analogue line ring to the caller 3 rings before they start ringing on the Mitel handsets
The Mitel is waiting for the Calling Line information (CLI) from the line provider
Stop the Mitel waiting for this information by turning the feature off in Class of Service (COS) for the trunk.
ANI/DNIS/ISDN/ Number Delivery Trunk = NO
If you do not know how to find which COS the trunk is using, message me.