DSL Speed Issue

I ran into a rather intriguing problem recently. My mothers DSL was very slow, she wasn't even getting half of what she paid for. After an upgrade she still didn't see any increase in speed.

The customer representatives said it was because she was too far from the source to get any better speed; which I knew could be a potential factor, however her issue seemed greater than just that. After a great deal of pain and effort one company tech finally had my mother unplug her phone from the DSL filter and immediately all the speed was received.

So we learned that the little DSL filters are not capable of supporting both a computer and a phone. I assume separating two signals instead of one is just too much for the small devices to handle. Using a separate filter solved the issue and allowed my mother to have both fast internet and a working land line.