BRI consists of two 64 kbps B channels and one 16 kbps D channel for a total of 144 kbps. This basic service is intended to meet the needs of most individual users. PRI is intended for users with greater capacity requirements. Typically the channel structure is 23 B channels plus one 64 kbps D channel for a total of 1536 kbps. In Europe, PRI consists of 30 B channels plus one 64 kbps D channel for a total of 1984 kbps.
H channels provide a way to aggregate B channels.
Customers will also need special equipment to communicate with the phone company switch and with other ISDN devices. Next Updated November 8, 2000.