Avaya Definity TN744C 8-Port Call Classifier Tone Detector (Refurbished)Avaya Definity TN744C Call Classifier Tone Detector Definity Card. More Information 8 ports of tone detection on the Time Division Multiplexing (TDM) bus that function the same as the TN2182, but the TN744C does not support call progress, tone generation, or clocking Supports digital signal processing of Pulse Code Modulation (PCM) signals on each port to detect tones and other signals Generation of tones is also supported for applications such as