| i have investigated this issue for a year or so.
its not just with the mitel switch but many others some of the chip and pin machines are designed abroad and only tested on direct lines.
its a voltage issue compatability
a dirct line works on 45v but an analogue ext on most systems is around 20v....this is the problem and the manufactures state in the handbook there is no guarante that it will work on pabx.
to keep customers happy use a dircet line |