Broadband Integrated Services Digital Network (B-ISDN) is an advanced communication network concept developed to provide high-speed digital transmission of voice, data, video, multimedia and other information services over a common network infrastructure. It evolved from Narrowband ISDN (N-ISDN), which was mainly designed for voice and relatively low-speed data communication. B-ISDN was intended to support broadband applications requiring much higher transmission capacity and better quality of service. The basic objective of B-ISDN is to integrate different types of communication services into a single digital network. Traditional networks generally used separate infrastructures for telephone calls, television, computer communication and other services. B-ISDN seeks to provide these services through a unified broadband network. This makes it suitable for multimedia communication and interactive applications. B-ISDN is primarily associated with Asynchronous Transfer Mode (ATM) technology. ATM is a high-speed switching and multiplexing technique in which information is divided into small, fixed-size units called cells. Each ATM cell consists of 53 bytes, including a 5-byte header and 48-byte payload. The fixed cell size allows efficient switching of different types of traffic and supports both continuous and bursty data