In central monitoring protocols, which signaling format is most used?

• A. Pulse
• B. IP
• C. FSK
• D. DTMF

Answer: (D)

Signaling format is about how the alarm panel sends information to the central station over the telephone path. DTMF uses the standard keypad tones to convey digits and simple commands, and this tone-based signaling rides directly on a regular phone line. Because telephone networks and central stations are built to detect and interpret these tones, DTMF has wide compatibility and is easy to implement in many systems, making it the most commonly used method in traditional central monitoring. Pulse dialing is an older dialing method and not used for conveying alarm data; IP signaling is a modern network approach that isn’t the typical protocol for traditional dial-up monitoring; FSK is used in some data-modem contexts but isn’t as universally supported as DTMF.