The ISDN is a set of international digital telephone switching standards. ISDN networks, which can be used to transmit voice, data, and video, offer the advantages of error-free connections, fast call setup times, predictable performance, and faster data transmission than possible using modems over traditional analogue telephone networks. Basic ISDN services combine voice and data, while broadband services add video and higher-speed data transmission. As telephone companies have progressively installed ISDN services, there has been much experimentation with distance education applications, notably for audiographic conferencing and multimedia desktop conferencing.

ISDN resources (external links)

• ISDN—What is it? Available at: http://www.isdnzone.com/info/isdnover.htm Permission to link granted.

• ISDN. Available at: http://www.cis.ohio-state.edu/~fine/ISDN Permission to link granted.

• Philman, Mike. Alphabet Soup. Available at: http://www.abctelecon.com/alphabet.htm Permission to link granted.