Calling Number Delivery is better known as Caller ID. It is a telephone service intended for residential and small business customers. It allows the called Customer Premises Equipment to receive a calling party’s directory number and the date and time of the call during the first 4 second silent interval in the ringing cycle. In caller id the data words are encoded in ASCII and represent the following information. The first two words represent the month, the next two words represent the day of the month, the next two words represent the hour in local military time, the next two words represent the minute after the hour, and the calling party’s directory number is represented by the remaining words in the data word field.
Caller ID may be used to track down or limit the impact of prank calls, telemarketers, and other intrusions. Some mobile phone providers used the caller ID to automatically connect to voice mail when a call to the voice mail number was made from the associated mobile phone number, bypassing the need to enter a password. Caller ID is a simple string of data that can be read and generated very simply by small computer programs and even some inexpensive devices. Calling ID is the identification of whom you are calling, or connecting to, as opposed to caller ID identifying who calls you.
