WhoCalls Caller ID detection

WhoCalls will use your modem to detect the CallerID of a calling party. Caller ID (caller identification or CID, and more properly calling number identification CNID, also known as CLID:calling line identity or CLIP:calling line identification presentation) is a telephone service that transmits the caller number to the called party telephone equipment during the ringing signal or when the call is being set up but before the call is answered.