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.
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 kbps "bearer" (B) channels and one 16 kbps "delta" (D) channel.