What are the differences between ISDN and IP and what does it mean in terms of usage?
ISDN: Integrated Services Digital Network ISDN-based videoconferencing provides a guaranteed picture and audio quality at a known price. It is therefore mainly suited for group meetings, long-distance interviewing and similar applications where high-quality audio and reasonable-to-good quality picture is necessary. ISDN is supported by telecoms service providers throughout the UK, Europe, North America, the Far East and Australia. The ISDN service is designed to provide reasonably high data transmission rates for digital data and its digital telephone links can be used to support videoconferencing. Each ISDN channel provides 64 kilobits of data per second (kbps). At least two ISDN channels are used for videoconferencing (ISDN-2), hence for links in UK the cost is twice that of a voice telephone call. Costs for ISDN-2 within the UK and Europe are quite reasonable and are shown in Question 5. ISDN-6 is obviously more expensive but may well be justified for the significant improvement in
