What is ISDN? Stands for "Integrated Services Digital Network." ISDN is a telecommunications technology that enables the transmission of digital data over standard phone lines. It can be used for voice calls as well as data transfers (internet), just like an ADSL phone line in your home. However, just like ADSL connections being used to provide broadband, ISDN is an old technology. Why is it coming to an end? BT have decided to stop providing this service. There are now faste