ISDN works by giving you two phone lines, with most telephone companies, called B Channels, which allows the user to transfer data to their PC at the same time as making a phone call. This means two operations can be carried out at once which is the first major advantage with ISDN. Another advantage of ISDN is that if you are only using the line to transfer data and not to speak as well then you can use both lines to transfer data at once increasing the transfer time to 128,000 bps which is over 3 times faster than the fastest modems making ISDN much quicker than standard Data Communications types.

ISDN uses Baseband transmission but there is also another version called B-ISDN, which uses a wideband transmission. This is the best kind of ISDN as it ups transfer rates to 1.5 MBps, which is extremely fast. A disadvantage with this though is that it requires the user to install optical fibre wires instead of phone lines, which are extremely rare in the UK and can be very expensive, making this option very uncommon.

You can purchase ISDN from the official BT internet site. Click on the link below!!!