A digital or UNIStim phone is assigned a Malicious Call Trace (MCT) button. During an active call, the user presses the MCT button, if the call is malicious.

A Feature Access Code (FFC in CS 1000) can be defined to initiate MCT from an analog phone. To trigger the MCT trace on an analog phone, initiate a transfer (do a switch hook flash) and dial the FAC. The user is then placed back in the call with the malicious caller. This can be done with digital and UNIStim phones that do not have an MCT button but do have a transfer button.

The call is then logged on the server side, including a screen display which is visible to administrator. A limited subset of trunking interfaces to the public network also permit sending the Malicious Call Trace to the PSTN or ISP.

The MCT key is mapped to the Communication Manager button mct-act (MCT Activation). The feature description on CS 1000 and Communication Manager is functionally identical. Device Adapter treats the mct-act button as the legacy MCT key providing the default localized label as per the endpoint firmware or reusing the “paper label” for endpoints without label firmware.