LERG™ Routing Guide
The comprehensive source for routing data (NPA NXXs, Thousands-Blocks, switches, homing arrangements, Rate Centers, etc.) covering the local exchange arena.
For new and emerging service providers, BIRRDS (Business Integrated Routing and Rating Database System) is the data tool to help your business ascend to the next level.
TPM™ Data Source
Contains NPA NXXs, Thousands-Blocks, Rate Center V&H, time zones, RAO, other rating related data for NXXs. (does not contain rates).
Telemarketing Data Source (TDS)
Used to identify wireline, wireless and paging exchanges (prefixes, NPA NXXs) by state, U.S., Canada and all of NANP.
NPA-NXX Active Code List (NNACL)
Data for all working NPA NXXs in the NANP, by Area Code (over 175,000 NXXs and 600,000 Thousands Blocks).
NPA-NXX Activity Guide (NNAG)
Future adds/deletes/changes to NPA NXXs, by Area Code (NPA).
LIDB Access Routing Guide (LARG)
Used primarily for Global Title Translations for Alternate Billing Services.
Calling Name Access Routing Guide (CNARG)
Used primarily for Global Title Translations for Calling Name Services.
Emergency Notifications (ENs)
Reports new NPA NXX openings that were reported late relative to industry guidelines (supports the LERG and TPM).
The North American Numbering Plan is divided into 86 Numbering Plan Areas (NPA). Each NPA has a unique three-digit code, which is also known as an area code.
The NXX is the three digits after an area code. It is also known as a prefix or exchange and identifies the specific central office that serves that telephone number.
The North American Numbering Plan (NANP) is the telephone number plan for telephone numbers in the U.S., its territories, Canada, and several Atlantic and Caribbean island countries.
Vertical & Horizontal are numbers derived from Latitude/Longitude, to pinpoint a location. They are used in assessing distances between two points for call rating, network access charges and related telephony needs.
A Rate Center is a geographic area that sets boundaries for local calling in the public switched telephone network (PSTN). Calls originating and terminating within these areas are considered local. A Rate Exchange Area is not the same as the Local Calling Area, which may extend across Rate Exchange Areas.
The Local Access Transport Areas (LATA) are geographical areas, defined by the U.S. Justice Department, that limit the range certain major local exchange carriers are permitted to transport telephone calls.