What is the difference between ADSL and IDSL?
ADSL is a service that runs at a different speed up and down, up to 8 megabits/sec down and 1 megabit/sec up, and is limited to distances of around 18,000 ft towards the high end, and cannot run through various devices that can be placed on the phone line such as a DLC (fiber in the line). IDSL is a service that is based on ISDN technology, runs at a maximum speed of 144 kilobits/sec each way, but can go anywhere ISDN can, at a distance of up to 50,000 ft with the currently used versions, and can run through most DLC.