PRI - Primary Rate Interface

Primary Rate Interface (PRI) is a telecommunications standard used widely for carrying multiple voice and data transmissions between network and user.

It is part of the Integrated Services Digital Network (ISDN) framework and consists of 23 bearer channels (B channels) for data plus one signaling channel (D channel) in North America and Japan (23B+D), while other regions typically use 30B+D.

This setup allows for efficient and high-capacity digital communication, suitable for large organizations and enterprises with substantial telecommunication needs.

PRI is commonly utilized for transmitting numerous simultaneous calls or data sessions across a single physical line.