B Channel

B channels B channels are the bearer channel.  They are used to carry voice or data information and have speeds of 64 kbps. Since each ISDN line (BRI or PRI) has more than one B-channel, more than one transmission can occur at the same time, using a single ISDN line. D channels The standard signaling protocol  is  transmitted  over a dedicated data channel called the D-channel. The D-channel carries call setup and feature activation information to the destination. This channel has speeds of 16 kbps (BRI) and 64 kbps (PRI). Data information consists of  control and signal information and packet-switched data such  as credit card verification.