Local Exchange Routing Guide (LERG)

The Local Exchange Routing Guide (LERG) is a database of telecommunications numbering resources for use in the administration and operation of the North American Numbering Plan (NANP) by the NANP administrator (NANPA) and telecommunications service providers. This data supports the local exchange network of the NANP and identifies planning changes in the network.

The database is maintained by private sector entities assigned by the Federal Communications Commission (FCC) to perform the NANPA function.

The database is produced in the TruOps Telecom Routing Administration (TRA) product group of iconectiv, LLC, formerly named Telcordia, a division of Ericsson since 2012.

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.

Data provided in the LERG Routing Guide describe the current local exchange network configuration within the North American Numbering Plan (NANP) and also future changes to the network.  The LERG Routing Guide is primarily designed to be used for routing of interLATA calls by interexchange carriers, but it also provides a wealth of other information, including:

A.    Local Access and Transport Area (LATA) Assignments

B.    Operating Company Numbers (OCNs) and Routing Contacts by OCN

C.   Numbering Plan Area (NPA) Assignments (Area Codes)

D.   Destination Code (NPA-NXX) Assignments, Including Switching Entity, Rate Center and Thousands-Block Pooling Assignments

E.    Details on Switching Entities and Tandem Homing Arrangements (Switch Interconnections)

F.    Rate Centers and Associated Localities

G.   Operator Services Access Tandem Codes (ATCs)

H.   Location Routing Numbers (LRNs)

The LERG is updated daily to the Peeredge SBC (specifically to the Traffic Manager (TM)).

Currently, there are over 1.3 million records in the LERG database.

For more information about the LERG click here.