Caller Identification - Caller ID

Caller identification is an optional telephone service that provides a receiving telephone device with the phone number of the originating caller, which can be displayed to the destination person prior to receiving the call. The caller ID is transmitted as a data parameter in the SS7 Initial Address Message from the originating end switch to the destination end switch in the process of setting up the call. Some caller ID services can also provide directory name listing information derived separately from the LIDB database. Caller ID information is typically transferred as a type-202-modem-compatible data signal between the first two ringing cadence cycles of the alerting tone.

This figure shows the calling number identification operation on a telephone line . Calling number identification operation starts with the reception of a call. When the call is received, the initial address message (IAM) contains the calling party number of the incoming call. The IAM may contain additional information such as the text name of the calling party. This example shows that the local switching system extracts this information and combines this information with the ring signal (using different frequencies and amplitudes) and sends it to the customer during the alerting (ringing) process. If the customer has the appropriate display equipment, the calling number information is display as the telephone rings.

Caller ID Operation Diagram

Additional Resources

Spirit Corporation Overview of Caller ID Signaling formats.

Private Branch Exchange - PBX Books

Introduction to Private Branch Exchange - PBX Book

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Introduction to Private Telephone Systems - PBX

This book covers key telephone systems (KTS), central exchange (Centrex), private branch exchange (PBX), computer telephony integration (CTI), voice over Internet protocol (VoIP) and wireless private telephone systems. Call processing features including automated attendant systems, automatic call distribution (ACD), Interactive voice response (IVR) and Voice mail (VM) are described.

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Call Centers For Dummies	Asterisk: The Definitive Guide	PBX Systems for IP Telephony
Call Centers For Dummies Real Bergevin, Bruce Simpson, Winston Siegel, Afshan Basith-Kinder,Paperback, Edition: 2, English-language edition,Pub by Wiley, John & Sons, Incorporated	Asterisk: The Definitive Guide Leif Madsen, Jim Van Meggelen, Russell Bryant,Paperback - Third Edition, Edition: 3, English-language edition,Pub by O'Reilly Media, Incorporated	PBX Systems for IP Telephony Allan Sulkin,Paperback, Edition: 1,Series: McGraw-Hill Telecom Series, English-language edition,Pub by McGraw-Hill Companies

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