Caller ID Boxes
What Is A Caller ID?
The caller ID box is a device that gets connected between the telephone Jack/line and the telephone. It displays the number of calling party so that one knows who is calling before picking up the phone. The caller ID facility is provided by the telephone company. The telephone company sends this information to the called party telephone lines after first ring tone.
How And What Information Is Provided?
The information is sent in the form of 1’s or 0’s. The technique used for sending information is called FSK (Frequency shift keying) where for sending 1 a tone of one frequency is sent and for sending 0 a tone of different frequency is sent. The scheme is known as 1200 baud Bell 202 tone modulation. The information may be sent in two formats depending on the telephone exchange. The first format is Single Data Message Format (SDMF) which includes the date, time and number. The second format is Multiple Data Message Format (MDMF) which adds a NAME field in addition to date, time and number information. The information sent is decoded by a modem inside the caller ID box and displayed.
Caller ID Feature
The caller ID boxes process the called ID information and provide many additional facilities to the users. The caller ID devices can be used to filter the calls. Some of the facilities available in advance boxes are following:
General Features
- The multi-function LED to indicate new calls and message waiting
- Dialing to call log numbers instantly.
handled.
- The caller in first list can make calls any time.
- The callers in second list might be able to call during defined time periods. The calls outside this programmed period are not passed on to telephone.
- The caller in third list is not allowed and their calls are not passed on to the telephone.
Call Filtering
- Creating number of lists for different number depending on how the call is to beVoice announcement
- Facility to record and announces pre-recorded names for frequent callers- Identification of incoming and call-waiting calls by announcing the caller`s recorded name or number in a high-quality, natural sounding voice.
- Identification of unknown calls (often telemarketers) and blocked calls by announcing "number unknown" and "number blocked."
