Ans. The Caller ID information is stored in a database called as CNAM database. When you make a call, you are the caller. The telecom carrier company is responsible to look up your name in the CNAM database and transmitting it to the recipient’s phone. If the operation failed to detect to access your identification information (our name), then either ‘No caller ID’ or ‘Unknown Caller’ will be displayed depending on the reason that makes the operation fail. If you have hidden the ID information using your phone features, then ‘No caller Id’ is transmitted to the recipient’s phone. Or if the carrier company could not interpret the ID due to certain restrictions, then the recipient gets the display as ‘Unknown Caller'.