The line information database (LIDB) is a collection of commercial

databases In computing, a database is an organized collection of data or a type of data store based on the use of a database management system (DBMS), the software that interacts with end users, applications, and the database itself to capture and ana ...

used in the

United States The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...

and

Canada Canada is a country in North America. Its Provinces and territories of Canada, ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, making it the world's List of coun ...

telephone A telephone, colloquially referred to as a phone, is a telecommunications device that enables two or more users to conduct a conversation when they are too far apart to be easily heard directly. A telephone converts sound, typically and most ...

companies to store and retrieve Calling Name Presentation (CNAM) data used for

caller ID Caller identification (Caller ID) is a telephone service, available in analog and digital telephone systems, including voice over IP (VoIP), that transmits a caller's telephone number to the called party's telephone equipment when the call is ...

services. In Canada, it is common for the client to apply their own Caller ID information, and this is allowed (and common in PBXs), provided the regulations regarding spoofing and fraud are not violated. The databases map telephone numbers to 15-character strings of caller names.

Class 5 telephone switches {{No footnotes, date=August 2008 A Class-5 telephone switch is a telephone exchange in the public switched telephone network (PSTN) that directly serves subscribers and manages subscriber calling features. Class-5 services include basic dial-tone, ...

, which provide end-office services in exchange areas, use the Signaling System 7 (SS7) signaling protocol to query the database. The data submitted to the Line Information Database is maintained by a customer's carrier, and most

incumbent local exchange carrier An incumbent local exchange carrier (ILEC) is a local telephone company which held the regional monopoly on landline service before the market was opened to competitive local exchange carriers, or the corporate successor of such a firm, in the Un ...

s (ILECs) like the

Baby Bells A Regional Bell Operating Company (RBOC) was a corporate entity created as result of the antitrust lawsuit by the United States Department of Justice against the Western Electric Company and American Telephone and Telegraph Company (AT&T) in 194 ...

, and

competitive local exchange carrier A competitive local exchange carrier (CLEC) is a North American telecommunications provider classification that emerged based on the competition model of the Telecommunications Act of 1996 in the United States. The act required the previously esta ...

s (CLECs) provide access for customers. In addition, LIDB databases were available from Intelco,

Neustar Neustar, Inc. is an American technology company that provides real-time information and analytics for risk, digital performance, defense, telecommunications, entertainment, and marketing industries, and also provides clearinghouse and directory se ...

, TNS,

Qwest Qwest Communications International, Inc. was a United States telecommunications carrier. Qwest provided local service in 14 western and midwestern U.S. states: Arizona, Colorado, Idaho, Iowa, Minnesota, Montana, Nebraska, New Mexico, North Dako ...

, Sprint and

Verisign Verisign, Inc. is an American company based in Reston, Virginia, that operates a diverse array of network infrastructure, including two of the Internet's thirteen root nameservers, the authoritative registry for the , , and generic top-level d ...

in North America. Some carriers do not provide a database, and CNAM lookups are provided using alternate methods, aggregated data from other sources, such as social media. In the US, caller ID name information is not transmitted from the originating office to the destination office. It is the terminating carrier that is responsible for providing the caller ID information to its customers. The carrier performs a database lookup using the caller's telephone number to obtain the name information for the caller ID service. If the data is with another carrier, then the terminating carrier must perform a lookup and pay a small ''dip fee'' to the carrier hosting the information. Wholesale rates for the fee are on the order of $200 to $600 per 100,000 lookups. Per carrier policy, the name of a person or business may be automatically added to the Line Information Database and the customer must opt-out to remain anonymous. Other carriers exclude identity information by rule, and require the subscriber to opt-in. If the identity information is not available, then the maintainer of the database often returns geographic information, such as the city and state. In case of a failure, the maintainer of the database may also return "NOT AVAILABLE". The CNAM databases are independent databases operated by LECs and other private companies. The called party's carrier has the responsibility to perform the CNAM lookup, and it is possible that lookups for the same telephone number from different locations return different name information.

References

Telephony Caller ID {{technology-stub

See also

References