well muheed ahmed,Integrated Services Digital Network or Isolated Subscriber Digital Network (ISDN), originally "Integriertes Sprach- und Datennetz" (German for "Integrated Speech and Data Net"), is a conceptual view of the network to user interface of the telephone system. In the 1980's the phone system was viewed as a way to transport voice, with some special services available for data. The key features of this network are that it integrates speech and data on the same lines, adding features that were not available in the classic telephone system. There are several kinds of ISDN defined: Basic Rate ISDN (BRI), Primary Rate ISDN (PRI) and Broadband-ISDN (B-ISDN).
ISDN is a circuit-switched telephone network system, designed to allow digital transmission of voice and data over ordinary telephone copper wires, resulting in better voice quality than an analog phone. It offers circuit-switched connections (for either voice or data) in increments of 64 kbit/s. Another major use case is Internet access, where ISDN typically provides a maximum of 128 kbit/s in both upstream and downstream directions(which can be considered to be broadband speed, since it exceeds the narrowband speeds of standard analog 56k telephone lines). ISDN channels may use BONDING to achieve a greater data rate.
Answered by
Debashis
, an ibibo Master,
at
2:19 PM on July 17, 2008