Malicious caller identification, introduced in 1992 as Call Trace, is activated by

Vertical service code A vertical service code (VSC) is a sequence of digits and the signals star (*) and number sign (#) dialed on a telephone keypad or rotary dial to enable or disable certain telephone service features. Some vertical service codes require dialing of ...

Star codes *57, and is an upcharge fee subscription service offered by telephone company providers which, when dialed immediately after a malicious call, records meta-data for police follow-up. A police report must be filed after each use, as law enforcement will only act on the trace once a formal police report is filed in regard to the call. Malicious caller identification facility, also called malicious call trace or caller-activated malicious call trace, when subscribed or enabled, works by allowing a phone call recipient to mark or flag the preceding phone call connection as malicious (i.e. harassing, threatening, obscene, etc.). The phone system will then automatically trace the call by flagging station to station billing and routing data including start and end times. The call trace is not dependent upon call duration (as envisioned in dramatic movie plots) and will record all meta-data regardless of source conditions - even if the call was made from an

unlisted number In telephony, an unlisted number (United States, New Zealand), ex-directory number (United Kingdom) silent number, silent line (Australia), or private number (New Zealand, and Canada) is a telephone number that, for a fee, is intentionally not l ...

, a

payphone A payphone (alternative spelling: pay phone) is typically a coin-operated public telephone, often located in a telephone booth or in high-traffic outdoor areas, with prepayment by inserting money (usually coins) or by billing a credit or debit ...

or a number with caller identification disabled. To protect privacy the resulting trace data is only made available to law enforcement. How the user activates this feature depends on their phone system — generally it is either in-band-signaling

DTMF Dual-tone multi-frequency signaling (DTMF) is a telecommunication signaling system using the voice-frequency band over telephone lines between telephone equipment and other communications devices and switching centers. DTMF was first developed ...

sequence such as the *57

or a special button attached to their phone generating an out-of-band signal. For analogue services, many exchanges will interpret DTMF sequences to activate POTS. Digital services, such as

ISDN Integrated Services Digital Network (ISDN) is a set of communication standards for simultaneous digital transmission of voice, video, data, and other network services over the digitalised circuits of the public switched telephone network. Wo ...

GSM The Global System for Mobile Communications (GSM) is a standard developed by the European Telecommunications Standards Institute (ETSI) to describe the protocols for second-generation ( 2G) digital cellular networks used by mobile devices such as ...

, enable the CPE to activate MCI via out-of-band signaling. Often with

PABX A business telephone system is a multiline telephone system typically used in business environments, encompassing systems ranging in technology from the key telephone system (KTS) to the private branch exchange (PBX). A business telephone syst ...

s with analogue phone connections, the PABX will interpret the DTMF and then activate the out-of-band signaling. Another way of identifying spam callers is checking through previous complaint history made by people about the phone number. The data is mostly crowdsourced and can be checked for previous complaints (i.e. Fraud, Scam, Harassment, Blackmail etc). Even if the number does not have previous history, reporting a complain publicly may help future victims of cyber fraud. MCI is the

ETSI The European Telecommunications Standards Institute (ETSI) is an independent, not-for-profit, standardization organization in the field of information and communications. ETSI supports the development and testing of global technical standard ...

standard, whereas MCT is the American one. They both do more or less the same thing though. In Canada, the service is usually marketed as call trace, and fees generally only apply when the service is used.

References

External links

Archive of Call Trace Recordings
{{FS1037C Telephone service enhanced features

See also

References

External links