Telcordia LERG Routing Guide
The Telcordia LERG Routing Guide is a comprehensive data product produced monthly by the Telcordia Routing Administration (TRA). It is 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 Telcordia Technologies, Inc., a division of Ericsson since 2012.
Content and purpose
The LERG provides data to support the routing of telephone calls by service providers in the public switched telephone network (PSTN) and the interconnection points of the PSTN with Internet Protocol (IP) networks.
In addition to the basic PSTN numbering data, Telcordia provides additional related data sets that supports a wide range of business needs of telecommunication service providers.