Anything (other than the DSL modem) that connects to phone
line 'not through filter' will eat your DSL signal. Filter
isolated DSL signal from not DSL equipment - to keep your
phone and fax from eating the DSL signal. Filter does not keep
phone and fax from bleeding over. It keeps phone and fax from
eating your DSL signal. Changing phone line sounds one simple
solution.

A major eater of DSL signals (a usual suspect) are plug-in
protectors; that don't provide effective protection anyway and
cost more money than effective protectors.

Doug Kanter wrote:
Thanks for the info, Bill. I can handle the wiring, but another idea
comes to mind. My fax line bypasses the AT&T box completely, and its
jack sits right next to the fax machine and the DSL modem. I'm going
to have the phone co. switch the DSL to that line. Voila. No wiring -
just plug in the filter/splitter.