Multitech FaxFinder Reference Manual page 8

FaxFinder Reference Guide: IP Office PBX Inter-Operation
Specify the Extension to be connected to the FaxFinder.
Set the Caller Display Type field to DTMFF.
These settings determine the type of DTMF signaling that the IP Office PBX will present to the FaxFinder.
You will need to assign an extension for every port on the FaxFinder.
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