Why is DSL pre-qualification necessary?
The availability of DSL has a lot to do with you phone lines and your phone company. The lines that we use to provide DSL to you, are owned by a phone company, and they control the lines and equipment that will be providing the DSL signal to your home.
DSL pre-qualification test the lines for distance and equipment that may cause your lines to be in-compatible with DSL service. If you are to far away from the CO (Central Office), the signal will be too weak, and you DSL will not work. If your telephone lines are running through some newer digital phone switching equipment or voice over IP systems, then your lines may not support DSL. Pre-qualification will take all of these factors and more into consideration and essentially tell you if your line is capable with DSL.