[engineer]

not entirely true, depends when your house was built and what type of internal phone wire was used. I had to run separate cat 5 wiring out to the outside phone junction box where the DSL was added so it is split by the phone company now from the old inside phone wiring and into the new cat 5 wiring. That way there is no interference with the existing phones and I did not need a filter on each phone. Also that gives me a good wire to the DSL modem particularly if you hard wire in a network instead of wireless which I have done. splitter porvided by DSL company along with extra splitter in case the one fails.

[goatmanmitch]

That is a way we route around problems, and it is also the best way to do it. That is how I have my house set up. But often not necessary, and cat 5 is also not necessary. Cat 5 comes into play when your signal leaves your router and it can run an immense distance on cat five- but using it for your inside phone wire would only be beneficial if the drop line from the pole to your house was cat 5 and all the wiring back to the central office is cat 5 (or if you have fiber to the curb). Most of the lines on the pole would be more an equivalent to cat 3. A filter can be jerry-rigged in the terminal on the side of the house (and sometimes even the protector in the terminal can degrade performance) but a proper 'splitter' can only be obtained during a visit from a phone company technician. But needing to take these additional steps is very often not needed, about 90% of customers never need to have a technician visit your home.

Originally Posted by engineer

not entirely true, depends when your house was built and what type of internal phone wire was used. I had to run separate cat 5 wiring out to the outside phone junction box where the DSL was added so it is split now from the old inside phone and into the new cat 5 wiring. That way there is no interference with the existing phones and I did not need a filter on each phone. Also that gives me a good wire to the DSL modem particularly if you hard wire in a network instead of wireless which I have done.