The LERG Routing Guide contains current information about the local Public Switched Telephone Network (PSTN) as well as additional information about IP Networks and includes scheduled future activity associated with the networks. Initially designed for the routing of Inter-Local Access and Transport Area calls across geographic regions made by interexchange carriers, the LERG Routing Guide has evolved to provide support for information exchange between all service providers, such as Competitive Local Exchange Carriers (CLECs), wireless providers, Internet Service Providers (ISPs), Voice over Internet Protocol (VoIP) providers, and more. It has grown to serve as a resource for performing network analysis, marketing and demographic analysis and many other uses.

The LERG Routing Guide provides routing details to support interconnection agreements, saving companies time and potential loss of revenue. It supports proper routing and completion of all calls and helps to maintain customer satisfaction.

The LERG Routing Guide is available for web download as a set of CSV files (preferred) or fixed formatted data files.

The LERG Routing Guide is a valuable resource for:

• Engineers who manage how calls are routed and directed
• Network planners/architects who need to set up the right network paths to keep calls connected and efficient
• Those involved with preparing, supporting and maintaining interconnection agreements and changes
• Companies expanding into the telecommunications industry or a new market that need reliable insights into existing network infrastructure

Download a sample LERG

Each issuance of the LERG Routing Guide supersedes all previous issuances. Files are available that indicate records that were added, changed or removed on a month-to-month basis.

The LERG Routing Guide General Information Section is included with each LERG Routing Guide and provides information on: 

• Data Glossary (data definitions)
• System Codes (Routing Code 1XX), Service Codes, North American Numbering Plan Universal Central Office Codes (NXXs), and Operator Service Codes
• Signaling System 7 (SS7) Network Codes
• Vertical Service Codes
• Automatic Number Identification Information Indicator (ANI II) Digits Codes
• Also, high level information regarding:
  • 900 NXX Codes
  • Toll Free (e.g. 800) Codes
  • 5XX-NXX Non-geographic Codes
  • 6YY Non-geographic Codes (Canada)
  • 710 (US Government) NXX Codes

Benefits of LERG Routing Guide:         

• Properly route and complete all calls
• Avoid lost revenue and maintain customer satisfaction
• Get physical routing details to support your interconnection agreements and save your company time and money
• Prepare for the 2-3% per month network changes that occur by obtaining planned network change data months in advance
• Get Rate Center information used in rating and billing processes
• View daily updates of numbering and routing changes using LERG OnLine or LERG One Day Changes
   

data in the LERG includes:

Operating Company Numbers, Company Names, Routing Contacts	Country Code Assignments
NPA Information (i.e., Area Codes)	LATA Codes By Region
Destination Codes (Area Codes / Prefixes) (NPA NXX Thousands-Blocks assignments for the United States and its territories, Canada, Bermuda, and 16 Caribbean countries)	Oddball NXXs (e.g. 911, 976)
Switching Entity Record detail (e.g. Equipment Type, Latitude and Longitude Coordinates)	Rate Center details (e.g. Latitude and Longitude Coordinates) and Localities (including county and postal codes that currently pertain to only U.S. data)
Switch Homing Arrangements (tandem and other switch-to-switch interconnections)	Operator Access Tandem Codes (ATCs)
Location Routing Numbers (LRNs)	Local Interconnection Regions (Canada)

You may obtain a copy of LERG Routing Guide data file layouts and specifications at no charge by contacting the TRA Customer Care Center.

LERG One-Day Changes Process

Subscribers to the monthly LERG Routing Guide have the option to also subscribe to the LERG One-Day Changes Process at no additional charge. Data changes in the underlying databases are analyzed daily to provide files reflecting day-to-day changes. This produces a set of files that denote daily changes in a format consistent with the following subset of LERG Routing Guide files:

• LERG1 (OCN)
• LERG6 (NPA NXX)
• LERG7 (Switch)
• LERG7SHA (Switch Homing)
• LERG12 (Location Routing Numbers (LRNs))

The files provided in this process are in a flat (fixed-record) file format only. They contain only those records that have undergone a change (added, removed and modified) each calendar day and are not a complete file replacement. Integration of the changes into the LERG is the responsibility of the end user since users handle the LERG Routing Guide data in many different ways.

LERG One-Day Process data is downloadable from a secured Internet site and requires a logon and password from TRA. The LERG One-Day Changes Process is available free of charge to customers with a monthly LERG Routing Guide Enterprise License.

LERG OnLine:

LERG OnLine is a separate offer from the LERG Routing Guide. It provides web access to view LERG data and download query results.

This is an easy-to-use web-based GUI application available only to LERG Routing Guide Enterprise Licensees at a small increment above the LERG license fee. LERG OnLine is provided on an enterprise basis for the benefit of everyone at the subscribing company.

LERG OnLine is a means to access up-to-date LERG Routing Guide data and isolate specific information that a user may be interested in obtaining for online review and/or downstream processing. LERG OnLine provides these capabilities to LERG Routing Guide Enterprise Licensees without the need to expend time, effort and expense to develop and maintain local processes; purchase and/or use third party software; or expend unnecessary manual efforts to obtain data from the LERG.

LERG OnLine data is updated daily, it is not just a monthly snapshot of the data. It provides the ability to access updated LERG Routing Guide data without needing to develop processes to incorporate LERG One-Day Change Process data with the monthly LERG.

Data in LERG Online is essentially the LERG Routing Guide, although specific terminology may vary. 

The LERG Routing Guide is a valuable resource for:

• Engineers who manage how calls are routed and directed
• Network planners/architects who need to set up the right network paths to keep calls connected and efficient
• Those involved with preparing, supporting and maintaining interconnection agreements and changes
• Companies expanding into the telecommunications industry or a new market that need reliable insights into existing network infrastructure
   

Benefits of LERG OnLine:

• Properly Route and Complete all calls
• Get Rate Center information used in rating and billing
• View daily updates of numbering and routing changes