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.