Basic Rate Interface

Definition of Basic Rate Interface

Basic Rate Interface (BRI) is a telecommunication service in Integrated Services Digital Network (ISDN) technology that enables the transmission of voice and data over a single telephone line. BRI is composed of two 64 Kbps bearer channels (B channels) for data, voice or video, and one 16 Kbps data channel (D channel) for signaling and control purposes. This configuration, referred to as 2B+D, provides a total bandwidth of 144 Kbps.


The phonetic pronunciation of the keyword “Basic Rate Interface” is:/ˈbeɪsɪk/ /reɪt/ /ˈɪntərˌfeɪs/Breaking it down further would be:Basic – BAY-sikRate – RAYTInterface – IN-ter-fays

Key Takeaways

  1. Basic Rate Interface (BRI) is an Integrated Services Digital Network (ISDN) service that provides two 64 kbps bearer channels (B-channels) and one 16 kbps data channel (D-channel) for voice and data transmission.
  2. BRI is suitable for small businesses and residential users, offering simultaneous voice and data transmission over a single line, which allows for features like call waiting, caller ID, and video conferencing.
  3. BRI is a cost-effective and reliable communication solution that has been largely replaced by more advanced and versatile technologies like DSL, VoIP, and Fiber Optics, but is still in use in certain areas that lack access to these modern services.

Importance of Basic Rate Interface

The technology term Basic Rate Interface (BRI) is important because it refers to a specific type of telecommunication service based on the Integrated Services Digital Network (ISDN) protocol.

BRI is designed to provide an efficient and reliable means for transmitting voice, data, and video signals simultaneously over a single line, offering improved bandwidth allocation and faster connection rates compared to traditional analog telephone systems.

It consists of two 64 kbps bearer (B) channels for carrying user data and one 16 kbps data (D) channel for signaling and control purposes.

This allowed for greater flexibility in communication as it enabled users to achieve multiple connections at the same time, effectively improving their productivity and allowing for enhanced telecommunication services, such as video conferencing, to thrive.

Despite the prevalence of newer technologies, BRI’s significance lies in setting the foundation for today’s high-speed and versatile communication networks.


The Basic Rate Interface (BRI) is an integral component of the Integrated Services Digital Network (ISDN), which plays a critical role in establishing digital communication systems via telephone lines. Primarily used by homes and small businesses, BRI’s purpose is to enable swift and reliable data transmission over the conventional telephone network.

This technology not only supports voice-based communications but also allows users to access other forms of media, such as video and data, simultaneously within the same connection. As a result, BRI provides an efficient solution for integrating multiple channels of communication, minimizing the need for separate telephone lines for different services, and paving the way for enhanced user experiences.

Furthermore, BRI is primarily designed to be a cost-effective alternative for users who require manageable, high-speed communication capabilities. Consisting of two 64 Kbps bearer (B) channels and one 16 Kbps data (D) channel, BRI can transmit data at a maximum combined rate of 128 Kbps.

The two B-channels are employed to deliver voice, video, and data traffic, whereas the D-channel is dedicated to managing signaling and control information between the user’s device and the ISDN network. The BRI’s efficient channel allocation and multiplexing capabilities enable smoother and uninterrupted communication services, making it ideal for numerous applications, ranging from video conferencing to internet access.

Examples of Basic Rate Interface

Basic Rate Interface (BRI) is a telecommunications technology used in ISDN (Integrated Services Digital Network) services for the transmission of voice, data, and other services over telephone lines. BRI consists of two 64 kbps B-channels (bearer channels) and one 16 kbps D-channel (delta channel) which provide a total bandwidth of 144 kbps. Some real-world examples of BRI technology usage include:

Small business telecommunications: Small businesses often employ BRI service for their telecommunication needs. The two B-channels can handle multiple simultaneous voice calls and data transmissions, allowing employees to communicate efficiently with customers and vendors while sharing internet access.

Video conferencing: BRI can be used for video conferencing in professional settings. Often used in conjunction with other digital communication technologies, the B-channels allow for real-time video and audio communication between participants, while the D-channel can transmit control and signaling information.

Home offices and telecommuting: BRI is utilized by professionals working from home or in remote locations. It enables effective voice communication, faxing, and data transfer, ensuring that users can collaborate with team members and access necessary resources while away from the office.

Basic Rate Interface FAQ

What is Basic Rate Interface (BRI)?

Basic Rate Interface (BRI) is a type of Integrated Services Digital Network (ISDN) service that offers two 64 kbps B-channels and one 16 kbps D-channel for voice and data transmission. This service allows multiple digital data connections over a single phone line and is primarily used by small businesses and residential customers.

What are the main components of a BRI?

The main components of a BRI include two B-channels and one D-channel. The B-channels are known as “bearer” channels and are used for transmitting voice and data, while the D-channel, or “delta” channel, is responsible for signaling and control information.

What are the benefits of BRI?

BRI offers several advantages, including simultaneous voice and data transmission, faster and more reliable data transfer, and cost savings as it uses a single phone line for multiple connections. It also supports caller ID and other supplementary services.

How does BRI compare to Primary Rate Interface (PRI)?

BRI and PRI are both ISDN services, but they differ in terms of capacity and targeted users. BRI is designed for small businesses and residential customers, offering two B-channels and one D-channel. Meanwhile, PRI is intended for larger organizations and provides 23 B-channels and one D-channel (or 30 B-channels and one D-channel in Europe and other countries).

Is BRI still relevant in today’s telecommunication scenario?

While BRI was more common in the past, the rise in high-speed internet connections and Voice over IP (VoIP) services has caused its popularity to decline. However, it may still be used in some situations where traditional phone systems are preferred or required, or in rural areas where broadband services are not yet available.

Related Technology Terms


  • Integrated Services Digital Network (ISDN)
  • Bearer Channels (B Channels)
  • Delta Channel (D Channel)
  • ISDN Terminal Adapter (TA)
  • Primary Rate Interface (PRI)


Sources for More Information


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