Wholesale: Products & Services

Unbundled Local Loop -Digital Service Level 1 (DS1) Capable Loop - V36.0

History Log

NOTE: The Federal Communications Commission ("FCC" or "Commission") released Order FCC 20-152 on October 28, 2020, a Report and Order in WC Docket 19-308 for the Modernizing Unbundling and Resale Requirements in an Era of Next-Generation Networks and Services ("Order"), which became effective February 8, 2021, and altered CenturyLink’s obligations to provide certain unbundled network elements. As such, these services will no longer be available after the following transition periods, consistent with the terms of the UNE Modernization Forbearance Amendment: 1) DS1- new orders not available after February 8, 2023; 2) DS3- new orders not available as of February 8, 2021; 3) DS0/ADSL/xDSL/ISDN BRI - new orders not available after February 8, 2023; 4) UNE Subloops and NIDs- new orders not available as of February 8, 2021; 5) Dark Fiber Transport- new orders not available as of February 8, 2021; and 6) OSS- subject to the transition periods applicable to the corresponding UNEs. The wire center lists pertaining to this order can be found at: http://www.centurylink.com/wholesale/clec.html.

Product Description

Unbundled Local Loop - Digital Signal Level 1 (DS1) Capable Loop provides a transmission path between the Central Office (CO) DSX-1 panel or equivalent and the loop demarcation point at the end-user premises. DS1 Capable Loop transports bi-directional DS1 signals with a nominal transmission rate of 1.544 megabits per second (Mbps). The service is provided using any of the following options:

  • Metallic based span with High-Bit-Rate Digital Subscriber Line (HDSL) or T1 equipment
  • Channel of a fiber based system
  • Combination of both fiber and metallic

General information regarding Unbundled Local Loop products is described in Unbundled Local Loops – General Information.

Product Diagram


DS1 Capable Loop is available where facilities exist throughout CenturyLink QC.

Omaha Forbearance Wire Centers are described at CenturyLink Non-Impaired Wired Center Lists for Loops and Dedicated Transport. In those cases, the DS1 equivalent facility is available only via CenturyLink’s Special Access Tariffs.

Terms and Conditions

General Interconnection Agreement, regulation and policy information for DS1 Capable Loop is described in the Terms and Conditions section of Unbundled Local Loop - General Information.

You may utilize the DS1 Unbundled Loop product to serve a location where you have multiple end user customers at a single multi-tenant location. Unbundled Loops are not available for telecommunications services provided directly to you for your own administrative purposes. An unbundled loop is defined as transmission facility between a distribution frame (or its equivalent) in a CenturyLink central office and the loop demarcation point at an end user customer premises.

A requesting telecommunications carrier may obtain a maximum of 10 (ten) Unbundled DS1 Loops to any single building in which DS1 loops are available as Unbundled Loops.

Technical Publications

Technical characteristics, including Network Channel/Network Channel Interface (NC/NCI™) Codes are described in Technical Publication, Interconnection - Unbundled Loop, 77384. Technical details for DS1 Capable Loops are specified in Technical Publication, 1.544 Mbit/s Channel Interfaces, 77375.


Rate Structure

Recurring charges are comprised of the following rate elements:

  • DS1 capable loop
  • Interconnection Tie Pair (ITP), per connection (a DS1 ITP for DS1)

Recurring charges are billed on a month-to-month basis.

Nonrecurring charges depend on the Installation option chosen. A nonrecurring charge applies to the installation of service(s) and in some states a disconnect service(s) charge will apply. Nonrecurring charges are billed after the service is rendered. Term contracts are not available.

Additional charges can apply. See Rate Structure under Pricing section of Unbundled Local Loop - General Information.


Rates are available in Exhibit A or the specific rate sheet in your Interconnection Agreement. If there are elements that are not in your Interconnection Agreement, contact your CenturyLink Service Manager.

Tariffs, Regulations and Policy

Tariff, regulations and policies are located in the state specific Tariffs/Catalogs/Price Lists.

Optional Features

There are no optional features available with DS1 Capable Loop.


Features Benefits

Market Presence

  • Allows you to provide Local Exchange services to your end-users

Low Cost

  • Allows you to lease facilities from CenturyLink at wholesale rates


See Features/Benefits.


Product Prerequisites

If you are a new Competitive Local Exchange Carrier (CLEC) and are ready to do business with CenturyLink, view Getting Started as a Facility-Based CLEC. If you are an existing CLEC wishing to amend your Interconnection Agreement or your New Customer Questionnaire, additional information is located in the Interconnection Agreement.


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

Prior to ordering a DS1 UBL, CLECs must have a certification form on file.  That form certifies that the CLEC:

  1. Is using the circuit for local traffic.
  2. Is ordering a circuit in an impaired Wire Center as filed by CenturyLink QC.
  3. Is ordering a circuit that does not exceed the cap in an impaired Wire Center as filed by CenturyLink QC
  4. Is not accessing an unbundled network element for the exclusive provision of mobile wireless services or interexchange services.

The Certification of Remand Order Criteria High Capacity Unbundled Transport, Unbundled Loop, and Combinations form is kept on file at CenturyLink subsequent to submission to the Account Team / Sales Executives and Service Managers.

Loop Qualification

The EASE-LSR User's Guide together with the Loop Qualification Raw Loop Data and CLEC Job Aid detail the information applicable to pre-ordering functions.

CenturyLink strongly recommends the use of pre-ordering functionality to assist in achieving increased service request flow through and accuracy, which will result in reduced service request rejects.

The following activities may need to be performed by you in preparation for the issuance of the service request:

  • Validate address
  • Validate Connecting Facilities Assignment (CFA)
  • Review Customer Service Record (CSR)
  • Check facility availability
  • Query Raw Loop Data (RLD)
  • Query Fiber Data Report

These activities will enable you to verify the type of facility and the loop make-up of the Unbundled Local Loop, which will assist you in identifying the appropriate service request intervals located in the Service Interval Guide (SIG).

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


General ordering activities are described in the Ordering Overview.

When submitting requests where the end user location is a multi-tenant environment, you must place your company name followed by the word "MTE" in the "Name" field on the End User (EN) form.

Unbundled Local Loop Installations Options

Six installation options are available for Unbundled Local Loop. Detailed information about the different installation options is available in the Ordering section of Unbundled Local Loop - General Information.

Circuit ID (ECCKT)

DS1 Capable Loops are assigned with Circuit Identification numbers. Detailed information about the Circuit Identification number format is available in the Ordering section of Unbundled Local Loop - General Information.

Required Forms and Activity Types

DS1 Capable Loop service request are submitted using the following Local Service Ordering Guidelines (LSOG) forms:

  • Local Service Request (LSR)
  • End User (EU)
  • Loop Service (LS)
  • Directory Listing (DL), if applicable

Field entry requirements are described in the LSOG. Valid LSR ACT types are described in the Ordering section of Unbundled Local Loop - General Information.

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

A Design Layout Record (DLR) request is described in the EASE-LSR XML Network Disclosure Document and the EASE-LSR User’s Guide.

Service requests can be rejected for various reasons. Error and rejection notifications are described in the Ordering Overview.

Service interval guidelines are found in the SIG.

Provisioning and Installation

General provisioning and installation activities are described in the Provisioning and Installation Overview and in the Provisioning and Installation section of Unbundled Local Loop - General Information.

CenturyLink DS1 Capable Loop Provisioning Process - Revision 6

Firm Order Confirmation (FOC) intervals are located in the SIG.

A jeopardy occurs on a service request if a condition exists that threatens timely completion. Jeopardy notifications are described in the Provisioning and Installation Overview.

Loss and Completion Reports are generated based on loss and gain account activity. Loss and Completion Reports are described in Billing Information – Additional Outputs – SMDR, Completion Report, Loss Report.

Hours of Operation

Installation hours are described in the Provisioning and Installation section of Unbundled Local Loop - General Information.

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.

Frequently Asked Questions (FAQs)

This section is being compiled based on your feedback.

Last Update: November 4, 2021

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