DSL is a service that connects us to the internet with a high-speed connection over your phone line. When you order it, in a way it can be thought of as adding a feature to your phone line - like call waiting or caller ID. But a lot more goes into adding DSL to a phone line than just "turning on" the service.
When you order DSL, a line check is run on your phone line. This line check determines multiple things. It will determine how far you are from the office ( or serving terminal ) in loop length where the DSL is coming out of. (The distance of the cable from the terminal to your address is known as the loop length.) DSL has a maximum distance of 18,000 feet in cable length that it can go through without degrading the signal too bad. The line check will also determine if you have bridge taps or load coils on your line. A Bridge tap can be thought of as a way to run one line to the central office and split it into multiple lines in the field. Not all Bridge Taps can keep you from getting DSL, but longer ones can interfere with the quality of the signal. A Load coil is essentially a way to increase the distance and quality of a voice call on a phone line - like an amplifier. Bridge Taps or Load Coils that will affect the DSL service may need to be removed in order for the line check to run clean for you to receive DSL.
