Wholesale: Products & Services

Product Catalog (PCAT)

Commercial Wholesale Local Voice (WLV) - Integrated Services Digital Network (ISDN) Basic Rate Interface (BRI) - V1.0

History Log

Product Description

Wholesale Local Voice (WLV) products provide local exchange telecommunications services to end-users on behalf of Competitive Local Exchange Carriers (CLECs) at competitive wholesale commercial rates. General information about WLV can be found in the Wholesale Local Voice (WLV) General Information PCAT.

WLV Integrated Services Digital Network (ISDN) Basic Rate Interface (BRI) is an all-digital communications technology that provides services and capabilities not available through standard analog technology to your end-users that is functionally equivalent to CenturyLink's retail ISDN BRI services. The ISDN digital architecture provides a high-speed, integrated transfer of voice, data and video over the same line, using the Public Switched Network (PSN). WLV ISDN BRI products are finished services requiring neither CLEC collocation nor other CLEC network involvement, and are combinations of the following network elements:

  • An ISDN BRI Capable Unbundled Local Loop
  • A Digital Line Side Port (Supporting ISDN BRI) including Local Switch Usage and any optional switch features
  • Shared Transport

ISDN BRI provides for two simultaneous voice connections and a low-speed data connection over existing telephone lines. The loop portion of this service is provided on a 160 kilobits per second (Kbps) Digital Subscriber Line (DSL) channel that has an information rate of 144 Kbps and is divided into three channels:

  • Two "B" channels capable of providing switched voice and switched data transmissions, allowing two simultaneous separate 64 Kbps connections of either type. B channels do not support packet switched data transmissions or out-of-band message signaling. Depending on the end-user's Customer Premises Equipment (CPE), the two B channels can be combined (bonded) into one high-speed 128 Kbps link.
  • One "D" channel capable of 16 Kbps. The D channel supports out-of-band message signaling and packet data functionality and does not support voice applications. This channel can simultaneously route up to 15 data calls.

In each ISDN-capable switch, ISDN BRI configuration groups or capability packages are programmed into the ISDN BRI common block according to Telecordia National Standards. Telecordia ISDN Ordering Codes (IOCs) identify the different pre-programmed configuration groups or capability packages. The CPE vendor will work with you to select the appropriate IOC for your needs. If you require an ISDN BRI arrangement that is not supported by an IOC, you can request the specific arrangement of features and functions Universal Service Order Codes (USOCs) and Field Identifiers (FIDs) to accommodate your needs.

The CenturyLink ISDN BRI standard feature package includes all standard features identified in the Tariffs/Catalogs/Price Lists. You should contact a CPE vendor to determine if your end user's CPE can support standard features and to learn more about how the features work with the CPE.


ISDN BRI is available where facilities exist throughout CenturyLink QC.

Terms and Conditions

Depending on the end-user's CPE and the number of lines ordered, limitations may exist regarding how many ISDN devices can be supported or active at one time. In general, standard network interface CPE supports from one to eight ISDN devices (telephone, facsimile, desktop computers, video units, etc.) with the following limitations per loop:

Switch TypeB Channel TerminalsD Channel TerminalsAdditional Information
DMS™-100Maximum of twoMaximum of sixA packet device cannot share a telephone number with a B Channel terminal
5ESS®Maximum of eightMaximum of sixGenerally, a maximum of four D channel terminals is observed unless some devices are used only rarely. The sending and receiving process can be inhibited if numerous terminals are using the D Channel at the same time.

Speed, functions and usage of the channel terminals are determined by the CPE.

ISDN BRI is available in certain ISDN capable 5ESS and DMS-100 switches, and in some instances their remote switches. Other types of CO switches (such as DMS-10, Ericsson, etc.) do not have ISDN capability. Information describing how to determine ISDN BRI availability is described in the Pre-Ordering section.

Technical Publications

Technical characteristics are contained in the applicable Tariff and may have references to certain Technical Publications.


Rate Structure

Monthly Recurring Charges (MRCs) for WLV are the sum of the monthly recurring rates of the service offerings ordered by the CLEC from their WLV Commercial Rates Sheets, Interconnection Rate Sheets, and appropriate tariffs.

Non-recurring Charges (NRCs) for WLV Installation, Disconnection (in some states), Conversion, and Feature activity are provided in the WLV Commercial Rate Sheets, Interconnection Rate Sheets, and appropriate tariffs.

A non-standard configuration charge applies per button (USOC N3CPB) when establishing an ISDN BRI arrangement that is not supported by an IOC.

WLV products include either one residential or one business directory listing (dependent on end-user application and the product requested) for each main telephone number, at no charge. Premium and privacy listings are also available. Regardless of residential or business directory appearance, all premium and privacy listings (with the exception of residential additional listings (e.g., USOC RLT) are categorized as business for rating purposes. Information describing directory listing availability and ordering is described in White Pages Directory Listings.


Depending on WLV Services ordered MRCs and NRCs are available in the:

  • Rate Sheet of your Commercial Agreement.
  • Rate Sheet or Exhibit A of your applicable ICA.
  • Applicable Tariff for features and services.

Nebraska WLV circuits only:

Effective September 19, 2011, you must place either the USOC XCBO2 (2-wire) or XCBO4 (4-wire) on your WLV LSR if your End-User is in an "Out of Town" location. Additional information on determining this classification is in Geographic Deaveraging - General Information.

Tariffs, Regulations, and Policies

CenturyLink tariffs, regulations, and policies are located in state specific Tariffs/Catalogs/Price Lists.

Optional Features

Optional feature descriptions and ordering information can be found in Optional Features Ordering Information.

The following non-ISDN analog features and/or services are not compatible with ISDN BRI. If a non-compatible feature exists on an account to be converted, remove the features and/or services from the account prior to converting.

  • Automatic Call Back
  • Call Waiting
  • Home Intercom
  • Anonymous Call Rejection
  • Call Forwarding Busy and Don't Answer (with certain types of CPE)
  • Wide Area Telephone Service (WATS)/800 Service

Remember to verify with the CPE vendor that your end user's CPE can support the ISDN BRI features.


ISDN BRI services provide voice only (circuit switched voice), voice and data (includes circuit switched voice, circuit switched data, and packet switched data), or data only (includes circuit switched data and packet switched data) applications.


Product Prerequisites

If you are a new CLEC and are ready to do business with CenturyLink, view Getting Started as a Facility-Based CLEC, and Interconnection Agreement, and Commercial Agreements.


General pre-ordering activities are described in the Pre-Ordering Overview.

Requirements for pre-ordering are described in Local Service Ordering Guidelines (LSOG) Pre-Order.

New ISDN BRI telephone numbers cannot be reserved using EASE-LSR. CenturyLink will return telephone numbers to you on the Firm Order Confirmation (FOC). If your end-user wants to convert an existing non-ISDN telephone number to Resale ISDN BRI, check with your CenturyLink Representative to see if the telephone number can be converted. Availability of ISDN BRI in the end-user's serving office does not guarantee that the prefix will be compatible.

CenturyLink strongly suggests that you complete the ISDN loop qualification pre-ordering process in addition to the CO ISDN availability pre-ordering process so that you are able to determine ISDN BRI service and facility availability. ISDN-BRI pre-qualification is a two step process.

Step 1: Verify the availability of ISDN BRI in the serving CO by referring to Network Disclosures. Select the appropriate state for the end-user's CO location. If the ISDN BRI DATE column is populated with "Deployed", the service is available.
Step 2: Verify ISDN loop facility availability at the end-user's address as described in the EASE-LSR User's Guide.

Service is not guaranteed until the ISDN has actually been installed. In certain rare instances, Facility Check may not be able to determine a design problem that would prevent installation of the service. In this situation you would be notified via a jeopardy notice. Additional information on the jeopardy process can be found in the Provisioning and Installation Overview.

Backhauling provides dialtone from an ISDN equipped switch that is not the end-user's local serving wire center to the end-user's local serving wire center. All backhauling requests should be referred to your CenturyLink Representative.


It is important to review and understand the ordering procedures described in Wholesale Local Voice (WLV) General Information PCAT.

General ordering activities are described in the Ordering Overview.

ISDN BRI service requests are submitted using the following LSOG forms:

  • Local Service Request (LSR)
  • End User (EU)
  • Resale Service (RS)
  • Directory Listing (DL)

Field entry requirements are described in the LSOG.

Service requests should be placed using EASE-LSR Extensible Markup Language (XML) or EASE-LSR Graphical User Interface (GUI).

When requesting new ISDN BRI service, enter the ISDN Ordering Code (IOC) obtained from the CPE vendor. The IOC must be entered in the FEATURES field on the RS form.

If an IOC is not available, you must enter the USOC and FID information required for your ISDN BRI arrangement in the FEATURE and FEATURE DETAILS fields of the RS form. For assistance in ordering refer to 5ESS Ordering Information or DMS-100 Ordering Information and Optional Features Ordering Information/

To request Loop Conditioning, in the REMARKS field of the LSR form include an entry of "Loop Conditioning authorized". Without an entry in REMARKS, you have not authorized Loop Conditioning. If the service does not loop qualify and if you have not authorized Loop Conditioning the order will be rejected.

Disclosure information and other LSR instructions are available in Network Disclosures.

Provisioning and Installation

General provisioning and installation activities are described in the Provisioning and Installation Overview.

Upon receipt of an accurate and complete LSR including authorization of Loop Conditioning, you will receive a Firm Order Confirmation (FOC) based on the standard interval found in the Service Interval Guidelines (SIG). If at any time after you receive the FOC, and prior to the scheduled due date, CenturyLink determines that loop conditioning is required, CenturyLink will apply the Loop Conditioning interval and will re-FOC your LSR reflecting the new scheduled due date. The interval will begin on the date CenturyLink determines that loop conditioning is necessary and a supplemental LSR is not required.

If at any time after you receive the FOC, and prior to the scheduled due date, CenturyLink determines that the loop cannot be conditioned to loop qualify, you will receive a jeopardy notification via EASE-LSR. The jeopardy notification will provide you information on how to proceed.

Maintenance and Repair

General maintenance and repair activities are described in the Maintenance and Repair Overview.


Customer Records and Information System (CRIS) billing is described in Billing Information - Customer Records and Information System (CRIS).


View CenturyLink courses by clicking on Course Catalog.


CenturyLink contact information is located in Wholesale Customer Contacts.

Last Update: October 29, 2020