Wholesale: Products & Services

Resale - Uniform Access Solution (UAS) - V11.0

History Log

Product Description

CenturyLink's retail telecommunication service, Uniform Access Solution (UAS), is available for resale by Competitive Local Exchange Carriers (CLECs) to their end-users. Additional information about resale of CenturyLink's retail services can be found in the Resale General Product Catalog (PCAT).

UAS is a digital service offering that is similar to Direct Inward Dialing (DID®) but requires no DID trunk termination. UAS provides a channel that transmits a digital signal between the end-user premises and CenturyLink's central office (CO) switch, your Collocation space or an Interexchange Carrier (IXC) Point of Presence (POP). It provides an arrangement that allows trunks to function with one telephone number per Digital Service Level 1 (DS1) facility and allows end-users to 'channelize' (multiplex or demultiplex) the DS1 into 24 voice grade trunks using their Customer Provided Equipment (CPE) or your collocation space. UAS includes a DS1 facility with common equipment and a network connection that provides switching for local exchange and long distance network access.

At the end-user's request, the UAS facility may be provided using a fiber optic facility. Special construction charges may apply. For additional information and to determine availability contact your CenturyLink Sales Executive.

Each DS1 utilizes 24 voice and data channels configured as In-only or 2-way trunk side terminations (Advanced Trunks). 2-way trunks are established in two groups, one for incoming calls and one for outgoing calls.

UAS provides for:

  • Digital Exchange Service
  • Digital transmission facility at the speed of 1.544 Megabits per seconds (Mbps), equivalent to a DS1, between your end-user's premises and the CenturyLink CO
  • Multiplexing of the UAS facility in the CO to accommodate the 24 channels in the CO switch
  • Trunk side terminated trunks which are flat rated
  • One Plain Old Telephone Service (POTS) dialing number per trunk group.


UAS is available where facilities exist throughout CenturyLink QC.

UAS may terminate at an IXC POP it is limited to data service for Internet access only, terminating on the Internet or by an Internet Service Provider (ISP) hwo is your end-user. Voice Service may not terminate at the IXC POP.

Terms and Conditions

The following terms and conditions apply for UAS:

  • Available on an intra Local Access and Transport Area (intraLATA) basis only
  • Available as a stand-alone service or as an option on Integrated Services Digital Network (ISDN) Primary Rate Interface (PRI)
  • Available if a DID station number from a block of DID numbers is used, however, a Block Compromise charge may apply
  • UAS compatible Customer Provided Equipment (CPE) is required
  • When converting retail UAS to resale UAS both the trunks and the facility must be converted.
  • Available only when all channels are the same type and in the same group. Billing will apply for the full 24 channels of the DS1 even if your end-user elects not to turn up all the channels.
  • A fiber optic facility may be engineered if you specifically request it. If your end-user has a copper facility and wishes to convert to a fiber facility, a change order will be required.
  • Allowed to ride a higher facility, e.g., Digital Service Level 3 (DS3).
  • Available from Remote COs and on Foreign Exchange Service.
  • Loop Diversity and Avoidance is available. The primary application for Diversity and Avoidance is, in the event of a failure in the network, to provide continued communications by means of an alternate and/or redundant network.

UAS is not available with:

  • Access Lines and Private Branch Exchange (PBX) trunks
  • Feature Group A, B, C, or D Services
  • Other Private Line/Access Services cannot be combined on the UAS DS1
  • Joint User Service, as specified in the state specific Tariffs/Catalogs/Price Lists
  • SwitchNet 56®
  • Temporary suspension of service
  • Caller ID or Caller ID Blocking
  • Service guarantees that normally apply to Private Line Service
  • Commercial/Private Mobile Radio Carriers in the provision of service to their end-users
  • Interexchange Carriers in the provision of service to their end-users.

Technical Publications

Technical characteristics, including Network Channel /Network Channel Interface (NC/NCI™) codes, are described in Technical Publication, CenturyLink Uniform Access Solution Service, 77393.


Rate Structure

Additional rate structure information can be found in the Statement of Generally Available Terms and Conditions (SGAT), the state specific Tariffs/Catalogs/Price Lists, or your Interconnection Agreement.

UAS is billed on a month-to-month basis or on a fixed-period Contract Service Arrangement that varies by state.


Rates and/or applicable discounts are available in Exhibit A or the specific rate sheet in your Interconnection or Resale Agreement.

Tariffs, Regulations and Policy

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

Optional Features

Optional features and functions available for the facility include:

Optional features and functions available for the trunk include:

  • Hunting
  • Answer Supervision (2-way trunks only)
  • Call Transfer Trunk Side (2-way trunks only)
  • Extended Area Service (EAS) (5ESS switches and 2-way trunks only)
  • Trunk Group Overflow


Benefits of UAS include:

Features Benefits
Reliable network connectivity
  • CenturyLink's world class technology network is offered throughout CenturyLink QC.
Enhanced end-user service
  • Allows single number access
Available with minimal capital investment
  • Cost savings


Prime candidates for UAS service include:

  • Internet Service Providers (ISPs)
  • Financial Institutions
  • Call Centers
  • Health Care/Hospitals
  • Businesses
  • Government
  • Manufacturing
  • Education


Product Prerequisites

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

For fixed-period CSAs, contact your CenturyLink Sales Executive. A contract will need to be established and you must obtain the contract identification number. The contract identification number must be noted in the Variable Term Agreement (VTA) field of the Local Service Request (LSR) form.


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

UAS involves a two step pre-qualification process:

  • Verify switch port availability in the CenturyLink CO by contacting your CenturyLink Sales Executive.
  • Verify that DS1 facilities are available by following the "check facility availability" guidelines described in the EASE-LSR User's Guide.

CenturyLink strongly suggests that you complete both of these steps prior to submitting your request. By checking trunk availability in the CO and DS1 availability you will be able to determine if the service can be provisioned. If facilities are not available, you may place your request for UAS, however, your request may be delayed.

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

There are at least two CSRs for each UAS service configuration, the DS1 facility CSR, and one or more trunk CSRs for the services riding the DS1. When converting this product, both the facility and the trunks must be converted, and you must review both the facility and the trunk CSRs. Based on the type of request, subsequent changes may also require review of both CSRs.

The trunk CSR has a standard telephone number as the account telephone number and is available in EASE-LSR using the standard pre-order CSR request function. The facility CSR has a private line account number, also known as a Mechanized Account Number (MAN) or Special Billing Number (SBN). If you know the account number, you can obtain the facility CSR through EASE-LSR.

If you don't have the account number, you may find it cross-referenced on the trunk CSR. The cross-reference may appear:

  • Following the Customer Other Service (COS) Field Identifier (FID) in the Bill Section e.g., COS 206-T31-1234.
  • Following the Description (DES) FID or Works With (WW) FIDs after the trunk Universal Service Order Code (USOC) e.g., TD21X/TN 206-224-2222/WW 206-T31-1234.

If the facility account number is not referenced on the trunk CSR, locate the CFA. The CFA appears on the CSR and identifies the name of the facility the trunk rides, as well as the channel it occupies, e.g., CFA 101 T1ZF 23 PTLDOR63DS0 PTLDORWSCSC (Common Language Location Identifier (CLLI™) CLLI).

If you are unable to locate the facility CSR, call the CenturyLink Interconnect Service Center (ISC) and select the Centrex and Complex Resale option to reach the appropriate workgroup.

When contacting the CenturyLink ISC, be prepared to provide:

  • End-user name
  • Trunk account number
  • CFA information
  • Proof of agency authorization.

Depending on your needs, the CenturyLink ISC can:

  • Give you the account number of the facility so you can find the CSR in EASE-LSR
  • Fax, mail, or email the CSR to you
  • Review the CSR with you on the telephone.


It is important to understand the Resale General procedures before ordering UAS.

General ordering activities are described in the Ordering Overview.

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

Two service requests are required to establish new UAS service, one for the facility (DS1) and one for the trunks that will ride the DS1. Both requests must be issued at the same time and related to each other by using the 'RPON' field on the LSR form. When disconnecting UAS, both the facility and the trunks must disconnected.

The trunk service request is submitted using the following LSOG forms:

  • LSR
  • End User (EU)
  • Resale Service (RS)
  • Directory Listing (DL), as appropriate

The facility service request is submitted using the following LSOG forms:

  • LSR
  • Resale Private Line (RPL)

UAS is ordered similarly to Integrated Services Digital Network (ISDN) Primary Rate Interface (PRI) Facility and Trunks. Field entry requirements are described in the LSOG.

Unique UAS ordering requirements fields include:

  • Enter the appropriate UAS NC/NCI codes for the facility on the LSR form.
  • Type of Service (TOS) field on the LSR form is either 11 or 31 (first character is a 1 or 3, second the second and third characters are blank, the fourth character is blank or an F if the service involves Foreign Exchange.)
  • Enter the contract number in the VTA field on the LSR form, if applicable
  • HETBN USOC must be entered in the REMARKS field on the RPL form. The HETBN USOC and the NC/NCI codes will differentiate your UAS product request from the ISDN PRI product
  • FO6 USOC must be entered in the REMARKS field on the RPL form if you are requesting a fiber facility

Enter the following DID number information in the REMARKS field on the RS form:

  • Number of digits (e.g., 4,7,10)
  • Type of start dial (e.g., wink, delay, immediate) for 2-way trunks
  • Type of pulsing (e.g., Dial Pulse, Tone, Multi-Frequency)
  • InterLATA and IntraLATA Long Distance Carrier (Primary Interexchange Carrier (PIC) and Local Primary Interexchange Carrier (LPIC) - Not applicable on In-Only Trunks) Information regarding long distance carrier selection is available in the Long Distance Carrier Selection Overview.
  • Trunk Options in the REMARKS field on the RS form.

To order hunting, you must understand and discuss with the end-user the concept of glare. Glare occurs when both ends of a telephone line or trunk are seized at the same time. For instance, an outgoing call at the end-user's location seizes a trunk at the same time as CenturyLink seizes it to send an incoming call. To minimize glare, the CenturyLink CO should be programmed to hunt (seize trunks for incoming calls) in the opposite order from that used by the CPE for outgoing calls. For example, if the CPE seizes trunks in reverse numerical order (10-1) the central office should be programmed to hunt in numerical order (from trunks 1-10).

You must also determine glare resolution with the end-user. If the CPE and the CenturyLink CO both seize the trunk at the same time, one call is given priority and the other switched to another trunk. The company, which switches its call to another trunk, is "yielding to glare."

In the REMARKS Section of the LSR form, you must enter who "Yields to Glare". If you enter "CenturyLink Yields to Glare", your end-user's call is given priority. If you enter "(Your Name) Yields to Glare", the CenturyLink call is given priority.

The use of the term "hunting" is meant to demonstrate how Advanced trunks are selected for the next available call. It is important that you select the appropriate type as any subsequent changes may require a complete removal and rebuild of the entire trunk group.

Hunt type must be passed in the REMARKS section of the "trunk" LSR form for the trunk request for new installations (ACT N), changes (ACT C), and outside moves (ACT T). You may use the assigned acronym for each hunt type to specify your preference. Technical Publication 77393 describes hunting options available on UAS circuits.

The S2N USOC is required on all Out-only and 2-way DID trunk groups. The S2N USOC is associated with a telephone number that will be used for long distance billing and emergency 911/E911 identification. Multiple trunk groups can share the same S2N telephone number. Guidelines on how end-user information is updated for the 911/E911 system are located in Access to Emergency Services (911/E911).

The telephone number must be a dialable number that can be called back by emergency services personnel and answered by your end-user. Whenever possible, your end-user's published telephone number should be used for the S2N. When this is not possible, CenturyLink will accept a DID number, another POTS or trunk number, or a stand-alone DID number assigned specifically for this use.

When working with existing service, you should review the CSR to see if an S2N telephone number is assigned for each applicable trunk group. If the S2N telephone number is not on the CSR, you should contact your end-user to determine which number is to be used. The information should be provided to CenturyLink by populating "S2N" in the FEATURE field and the telephone number in the FEATURE DETAILS field of the RS form.

When requesting new service, you should determine which S2N telephone number assignment option your end-user prefers; published number, other number in a DID range, or stand-alone DID number. Populate the USOC "S2N" in the FEATURE field of the RS form and the chosen option in REMARKS, for example, "Use published number for S2N."

CenturyLink will provide the assigned S2N telephone number on the Firm Order Confirmation (FOC). It is your responsibility to provide the S2N telephone number to your end-user and/or their CPE vendor in order for the CPE to direct calls to the appropriate telephone set.

CenturyLink will error or reject your request if the information provided for UAS is contradictory or insufficient to provision the service. In most instances, you will receive a telephone call asking for a Supplement (SUP) to your request. If the information needed is not provided within four hours of the telephone call, your request will be rejected via fax. Following are some examples of requests that may error or reject:

  • Hunting requested on facility
  • Hunting requested on facility and not requested on trunks
  • NCI codes requests on facility and trunk requests do not match
  • Requested trunk type invalid on requested facility type

A Design Layout Record (DLR) for the facility is available upon request. Information for requesting and viewing a DLR is described in the EASE-LSR User's Guide.

Provisioning and Installation

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

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).


Local CenturyLink 101 "Doing Business With CenturyLink"

  • This introductory web-based training course is designed to teach the Local CLEC and Local Reseller how to do business with CenturyLink. It will provide a general overview of products and services, CenturyLink billing and support systems, processes for submitting service requests, reports, and web resource access information. Click here for Course detail and registration information.


  • This self-directed, web-based product training course provides you with knowledge of the CenturyLink Digital Service - Level 1 (DS1) product. You will learn how DS1 works and the options available. DS1 is a Private Line Transport service that is dedicated, high capacity and can transport digitally coded voice, data or video signals point to point between two customer locations at 1.544 megabits per second. For more information on creating and submitting a service request, please go to the centurylink.com Wholesale training web site. Web based and Instructor Led training courses which includes this information are titled: Introduction to Service Requests & Billing for CLECs (Forms Completion section) and ASR Private Line. Click here to learn more about this course and to register.

Digital Switched Service (DSS)

  • This self-directed, web-based product training course provides you with knowledge of CenturyLink Digital Switched Service (DSS). You will learn how DSS works and the options available. Digital Switched Service is a digital interface that provides PBX users with switched access from the customers PBX to CenturyLink's central office. DSS is the service that rides on the DSS/DS1 digital facility between the customer site and the central office switch. For more information on creating and submitting a service request, please go to the centurylink.com Wholesale training web site. Web based and Instructor Led training courses which includes this information are titled: Introduction to Service Requests & Billing for CLECs (Forms Completion section) and ASR Private Line. Click here to learn more about this course and to register.

PBX Trunks

  • This self-directed, web-based product training course provides you with knowledge of the CenturyLink PBX Trunks product. You will learn how PBX Trunks works and the options available. PBX Trunks are connections between an organization's PBX (Private Branch eXchange) and the outside telephone network. Telephone users within the customer's company share these connections for making and receiving calls outside the company's network. For more information on creating and submitting a service request, please go to the centurylink.com Wholesale training web site. Web based and Instructor Led training courses which includes this information are titled: Introduction to Service Requests & Billing for CLECs (Forms Completion section) and ASR Private Line. Click here to learn more about this course and to register.

View additional CenturyLink courses in the 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: April 9, 2015

SwitchNet 56® and DID® are Registered Trademarks of Century Link ™
CLFI™, CLLI™ and NC/NCI™ are Trademarks of Telcordia Technologies, Inc.