There is only one Caller ID protocol supported by the network service providers (telephone companies) in the United States and Canada. This protocol is specified in the Bellcore technical requirements standards and therefore may be properly referred to as the “Bellcore Caller ID Protocol”. This protocol includes the requirement to use Frequency Shift Keying (FSK) signaling. Since the “Bellcore Caller ID Protocol” uses FSK signaling, someone might incorrectly refer to this protocol as “FSK”.
The European Telecommunications Standards Institute (ETSI) specifies a different protocol for Caller ID. This protocol includes requirements for using both FSK and DTMF signaling. Since the “ETSI Caller ID Protocol” includes requirements for DTMF signaling, someone might incorrectly refer to this protocol as “DTMF”. The “ETSI Caller ID Protocol” is used in Europe and in South America but not in the US or Canada.
There are other protocols besides the Bellcore and ETSI Caller ID Protocols that are used by countries not located in Europe or the Americas.
All Uniden Caller ID products support the “Bellcore Caller ID Protocol” (“FSK”).
There are no Uniden Caller ID products which support the “ETSI Caller ID Protocol” (“DTMF”) or any other Caller ID protocol besides the “Bellcore Caller ID Protocol”.
