Local Exchange Routing Guide or LERG is a database of the first 6 digits of a telephone number. This is updated on a regular basis and provides information for routing telephone calls over the Public Switching Telephone Network. The Local Exchange routing guide enables identification of what local company the number belongs to. See also Exchange Area.
This article needs additional citations for verification. (May 2018) (Learn how and when to remove this template message)
The TruOps Telecom Routing Administration (TRA) is a comprehensive set of data products produced monthly by iconectiv, LLC. The data products are primarily used by telecommunications service providers operating within the North American Numbering Plan (NANP), which is World Zone 1. This data supports the local exchange network of the NANP and identifies planning changes in the network. The acronym LERG originally stood for Local Exchange Routing Guide, and is a trademarked term of iconectiv, LLC.