Basic Rate Interface

Basic Rate Interface or BRI is actually one of these two levels of services that are provided by the ISDN. This is meant for the smaller enterprises and home enterprises while the Primary Rate Interface or PRI is meant for larger users. The BRI comprises of dual bearer channels or B channels and a single D channel or Data channel. The D channel will carry signaling and controlling data while the B channel carries voice, data and other services.

Basic Rate interface vs Primary rate interface

Put simply, the BRI was meant for smaller use as it had limited capability of transferring data and voice over the same line. Primary rate interface, which was a step above the basic rate interface, allowed an added degree of rate and was thus suited for bigger enterprises.

Because of the ISDN it has become possible for multiple users to use services lines simultaneously. This set up is highly economical for the smaller industries wherein dedicated lines and modem costs need to be kept nominal. The bearer channel has 64 Kbps bit rate and the data channel has 16 Kbps bit rate. It is also possible to combine two bearer channels to get a data rate of 128 Kbps. The D channel will transfer data as packets while the B channels, having dedicated bandwidth, can send data through formatted and circuit-switched channels.