The primary rate interface (PRI) is a telecommunications standard for carrying multiple DS0 voice and data transmissions between two physical locations. Copy of the original phone of Alexander Graham Bell at the Musée des Arts et Métiers in Paris Telecommunication is the transmission of signals over a distance for the purpose of communication. ... In T-carrier systems Digital signal 0 (DS0) is a basic digital signaling rate of 64 kb/s, corresponding to the capacity of one voice-frequency-equivalent channel. ...

All data and voice channels are ISDN and operate at 64 kbit/s. // Integrated Services Digital Network (ISDN) is a circuit-switched telephone network system, designed to allow digital transmission of voice and data over ordinary telephone copper wires, resulting in better quality and higher speeds than that is available with the PSTN system. ...

North America and Japan use a T1 of 23 B channels and one D channel which corresponds to a T1 line. Europe, Australia and most of the rest of the world use the slightly higher capacity E1, which is composed of 30 B channels and one D channel. Two Network Interface Units, one with a single card, the other with two In telecommunications, T-carrier is the generic designator for any of several digitally multiplexed telecommunications carrier systems originally developed by Bell Labs and used in North America and Japan. ... B channel (bearer) is a telecommunications term which refers to the ISDN channel in which the primary data or voice communication is carried. ... D channel (delta) is a telecommunications term which refers to the ISDN channel in which the control and signalling information is carried. ... To meet Wikipedias quality standards, this article or section may require cleanup. ...

Fewer active B channels (also called user channels) can be used for a fractional T1. More channels can be used with more T1s, or with a fractional or full T3 or E3.

See T-carrier for DS0, T1, E1, T3, E3 and other carrier communications terms. Two Network Interface Units, one with a single card, the other with two In telecommunications, T-carrier is the generic designator for any of several digitally multiplexed telecommunications carrier systems originally developed by Bell Labs and used in North America and Japan. ...

In the Integrated Services Digital Network (ISDN), there are two levels of service: the Basic Rate Interface (BRI), intended for the home and small enterprise, and the Primary Rate Interface (PRI), for larger users. Both rates include a number of B-channels and a D-channel. Each B-channel carries data, voice, and other services. The D-channel carries control and signaling information. The Basic Rate Interface consists of two 64 kbit/s B-channels and one 16 kbit/s D-channel. Thus, a Basic Rate Interface user can have up to 128 kbit/s service. The Primary Rate Interface consists of 23 B-channels and one 64 kbit/s D-channel using a T1 line or 30 B-channels and 1 D-channel using an E1 line. Thus, a Primary Rate Interface user on a T1 line can have up to 1.544 Mbit/s service or up to 2.048 Mbit/s service on an E1 line. PRI uses the Q.931 protocol over the D-channel. The B and D channel sizes are dependent on the Framing format of the T1 circuit. ie. Super Frame(SF) is a 56kb channel and the Extended Super Frame (ESF) is a 64kb channel. // Integrated Services Digital Network (ISDN) is a circuit-switched telephone network system, designed to allow digital transmission of voice and data over ordinary telephone copper wires, resulting in better quality and higher speeds than that is available with the PSTN system. ... Basic rate interface (BRI, 2B+D, 2B1D) is an Integrated Services Digital Network configuration defined in the physical layer standard I.430 produced by the ITU. This configuration consists of two 64 kbit/s bearer channels (B channels) and one 16 kbit/s data channel (D channel). ... The ITU-T Recommendation Q.931 is ISDNs connection control protocol, roughly comparable to TCP in the Internet Protocol stack. ...

The Primary Rate Interface channels are carried on a T-carrier system line (in the U.S., Canada, and Japan) or an E-carrier line (in other countries) and are typically used by medium to large enterprises. The 23 (or 30) B-channels can be used flexibly and reassigned when necessary to meet special needs such as videoconferences. The Primary Rate user is hooked up directly to the telephone company central office.

See also

• Basic Rate Interface

Sources: From Federal Standard 1037C Basic rate interface (BRI, 2B+D, 2B1D) is an Integrated Services Digital Network configuration defined in the physical layer standard I.430 produced by the ITU. This configuration consists of two 64 kbit/s bearer channels (B channels) and one 16 kbit/s data channel (D channel). ... Federal Standard 1037C, entitled Telecommunications: Glossary of Telecommunication Terms is a United States Federal Standard, issued by the General Services Administration pursuant to the Federal Property and Administrative Services Act of 1949, as amended. ...