If you have A T & T DSL, they do "maintenance" every few months. They go into the modem and lower the setting on the speed. Ours has a speed setting from 2 to 7, some go from 1 to 11. They will set it as low as possible, and then your speed slows down and you will get shut out occasionally. You can go into the "2 wire" on your computer and raise it back to the maximum.