What is BISDN in Computer Network?

The B-ISDN (Broadband Integrated Services Digital Network) is a virtual circuit-switched network that can use high-speed packet switching services. B-ISDN uses a flexible multiplexing format called ATM (Asynchronous Transfer Mode) to deliver broadband services over digital networks.

B-ISDN represents an evolution from the original ISDN, designed to handle high-bandwidth applications like video conferencing, multimedia communications, and high-speed data transfer that require significantly more capacity than traditional voice services.

Service Categories

B-ISDN services are classified into two main categories based on the direction of information flow:

• Interactive Services − Bidirectional flow of user information between subscribers or between a subscriber and service provider

• Distribution Services − Unidirectional flow of information from service provider to subscriber

Interactive Services

Interactive services are divided into three sub-categories:

Conversational Services

Conversational services involve real-time exchange of information such as sound, video, data, or entire documents. Examples include:

• Video-telephony − Enhanced telephony with video capture, transmission, and display capabilities

• Video-conferencing − Voice and video communication between conference rooms or multiple individuals

• High-speed data transfer − Real-time transmission of large data files

Messaging Services

Messaging services involve non-real-time exchange of information between subscribers using store-and-forward mechanisms. These services allow users to send and receive messages when convenient.

Retrieval Services

Retrieval services provide subscribers with access to centrally-stored public information. Examples include:

• Broadband videotext − Retrieval of video images with sound, text, and graphics

• Video libraries − Access to movie collections and entertainment content

• Archive access − Retrieval of high-resolution pictures and records from data centers

Distribution Services

Distribution services are divided into two sub-categories:

Without User Presentation Control

These services involve central broadcast of information to many subscribers, where users have no control over data display. Examples include broadcast TV programs, electronic newspapers, and electronic publishing.

With User Presentation Control

Similar to the previous category, but information is offered as cyclically repeated frames, allowing subscribers to control the start and order of frame presentation. Examples include interactive electronic newspapers and tele-advertising.

Key Features of B-ISDN

Conclusion

B-ISDN represents a comprehensive broadband network architecture that supports both interactive and distribution services using ATM technology. It enables high-speed multimedia communications by providing flexible bandwidth allocation and integrated service delivery over digital networks.