Caller ID

Local Calls
Local call processing and caller options.


Caller ID features


Caller ID is one of the many features provided by local telephone companies. It consists of a caller ID box connected to your telephone set that receives information about all incoming calls. Depending on the telephone set model and brand, this information can also appear on the set's display without the need of connecting an external device. When the phone rings, a name and telephone number appears on the display which identifies the caller. What in fact occurs, is that the originating central office realizes a search of the caller's telephone number in its database and transmits that information over the network in order to be seen on the receiver's display. A further database lookup is done during this process, associating the number with the directory listing (if it is a listed number). In order for the Caller ID features to function, several items must be met: 1- All the switches over the network must support SS7 (Signaling System 7). 2- The call must be originated from a single-channel line, not from multitrunks like T-1's. 3- The caller must not block the information to the receiver. If these points are not met, the receiver will get a "Anonymous" or "Not Available" message on the display. Caller ID features usually have a slight installation charge and then a monthly charge for the service provided by your local telephone company.

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