>Beyond that 7-foot distance, is there a hard-and-fast
>formula for measuring attenuation? I'm prolly looking
>at an RJ-11 cable run extending 15-20 feet from a wall
>jack and am trying to get an idea of the viability of
>doing this.
For dialup? You will be just fine. Dialup isn't very picky about cable
length and attenuation... at least not at the levels you are likely to
deal with in a user environment.