Broadband ISDN Protocols and Interface Structures.

A broadband service is defined as a service which requires an information transfer rate in excess of the capacity of a primary rate interface that is 1.544 Mb/s (Megabits per second). The B-ISDN (Broadband Integrated Services Digital Network) is a circuit switched network that can be used for fast packet- switched services. The work is already underway to define and standardize B-ISDN in the CCITT (International Telegraph and Telephone Consultative Committee). Currently, B-ISDN uses the SONET (Synchronous Optical Network) architecture as a physical layer and the ATM (Asynchronous Transfer Mode), which is a proposed packet-like protocol.