Basic Rate Interface. The standard ISDN line, consisting of 2 B channels for data and 1 D channel for signalling. Also known as ISDN 2e, or sometimes 2B+D.
Basic Rate Interface within ISDN, abbreviated BRI. A digital interface to the PSTN over standard telephone wiring (twisted pair). Delivering SS7 interfaces to an end user at the Basic Rate - two 64k bits per second B channels carrying user data, with signaling on a 16k bits per second D channel.