
Basic Rate Interface
The ISDN Basic Rate Interface consists of three digital channels: one D channel and two B channels. These channels can be used simultaneously, and are often referred to as 2B+D.
Each ISDN B channel can be used separately to allow two different connected users at the same time. The ISDN B channels can also be combined to provide a total bandwidth of 128 Kbps.
Primary Rate InterfaceThe ISDN Primary Rate Interface, like BRI, has one D channel, but it has more than two B channels. The number of B channels for PRI differs in different locations.
•In North America and Japan, PRI consists of 24 digital channels: one D channel and 23 B channels.
•In Europe and Australia, PRI consists of 31 digital channels: one D channel and 30 B channels.
These channels can all be used simultaneously, and are often referred to as 23B+D (North America and Japan) or 30B+D (Europe and Australia).
Each ISDN B channel can be used separately to allow multiple connected users at the same time. The ISDN B channels can also be combined to provide a total bandwidth of 1472 Kbps (North America, Japan) or 1920 Kbps (Europe, Australia).
190 | Interphase Corporation |