BRI Single Line Service

ISDN Data and Voice Over Existing Phone Lines

Leverage your existing copper voice line for data connectivity to create a seamless, flexible, and cost-efficient voice and data communications solution.

CenturyLink® Basic Rate Interface (BRI): Single Line Service uses an ISDN digital network architecture to enable reliable data communications without the expense of dedicated lines, modems and cabling, while accelerating both voice and data far beyond the speed of standard telephone lines. Multiple communications can share a single line simultaneously, including voice, video, and data, with digital clarity. Multiple B channels for high-speed circuit-switched data, complemented with a separate D channel for low-speed packet-switched data, let you support a broad range of applications with optimal efficiency. 


Manage Costs

Utilize existing lines for a cost efficient data solution.

Optimize Efficiency

Use existing copper wiring for Internet connectivity, while remaining able to accept incoming voice or fax calls.

Support Multiple Devices

Share a single ISDN line across up to eight (8) devices.

Back Up Dedicated Services

ISDN can be used to provide a cost-efficient back up method for mission critical dedicated services.

*The Business Prime package does not include Business voicemail as a feature. Business voicemail can be purchased separately at a discounted rate.


Circuit-Switched Voice, Data, and Packet Functionality

Call Forwarding

Call Hold

Caller ID Blocking


Two Lines with Multiple Unique Telephone Numbers

Call Transfer

Caller Identification

Conference Calling

Message Waiting Indicator

How It Works

CenturyLink Basic Rate Interface (BRI): Single Line Service is a platform-based, switched digital service based on ISDN, a digital network architecture that provides both a voice connection and a high- or low-speed data connection simultaneously over existing telephone lines (i.e. twisted pair). CenturyLink BRI has a transmission rate of 144 Kbps divided into three channels. There are two B channels capable of 64 Kbps each and one D channel capable of 16 Kbps. Since the D channel is used for signaling, the B channels have a higher transmission rate than is currently available on a regular voice channel. Each B channel is capable of circuit-switched voice, circuit-switched data, or packet-switched data (individual case basis only). The D channel is capable of Q.931 or X.25 protocol signaling or X.25 packet-switched data.

Network Maps

The CenturyLink network covers the continental United States and has one of the largest fiber footprints. Internationally, we provide coverage to hundreds of destinations.

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