Q2:write short note on ISDN its service and layers?(3pts)

Answer 1

ISDN (Integrated Services Digital Network) is a set of communication standards for simultaneous digital transmission of voice, video, data, and other network services over the traditional public switched telephone network (PSTN). ISDN offers higher data transfer rates than traditional telephone lines, making it a popular choice for businesses requiring fast and reliable communication services.

ISDN operates at the physical and data link layers of the OSI model. The physical layer is responsible for transmitting digital data over the network medium, while the data link layer handles the framing and error detection of the data being transmitted. ISDN services include voice calls, data transfer, video conferencing, and other multimedia applications. It provides a range of service types, including Basic Rate Interface (BRI) for small businesses and home users, and Primary Rate Interface (PRI) for larger organizations with higher communication needs.