Basic rate interface
Basic Rate Interface (BRI, 2B+D, 2B1D) is an Integrated Services Digital Network channel consisting of two 64 kbit/s "bearer" (B) channels and one 16 kbit/s "delta" (D) channel, giving a total data rate of 144 kbit/s. The B channels are used for
voice or user
data, and the D channel is used for control and signalling and/or X.25 packet networking. BRI is the kind of
ISDN interface most likely to be found in residential service.
This article (or an earlier version of it) contains material from FOLDOC, used with permission. Update as needed.