Line Information Database (LIDB)

A Line Information Database (LIDB) is a record kept by the local telephone service provider that consists of a number of details for each customer. The categories included in a Line Information Database include subscriber information, such as a service profile, name, address and credit card validation information. For instance, caller ID name is stored in LIDB. The acronym LIDB often is pronounced "lid-bee."

LIDB is used in the United States and Canada by traditional telephone companies to store and retrieve Caller ID records. Local phone switches, also known as Class 5 switches, use SS7 signaling protocol to query these centralized databases and pass this information during call set up. The information includes subscriber's information such as service profile, 10-digit line number, service provider ID, equipment indicator and billing specifications.

Internetwork Calling Name (ICNAM) is a service that works in the same manner as LIDB. With ICNAM, rather than returning calling card or bill name validation data, the query data returned is the name of the calling party.

There are two main components to the Caller ID info seen by a receiver of a call: the number and the name. The number is the "easy" part, but the name takes a little more effort to set up.

• Setting your own CNAM within your PBX has no effect in the U.S. and many other countries. Only the CID number is transmitted to the terminating carrier, and those carriers then look up the name from a database.

• If you will be making calls to Canadian numbers, you can pass the Caller ID Name from your PBX.

In the U.S., CNAM information depends on what is stored in a Line Information Database (LIDB), which contains records of numbers and names. There are many different databases, and each carrier decides which database to use.