Bruce L. Bergman fired this volley in
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Except all I can get at 21KFT out from the CO is 384K down, 128K up,
and at&t won't let anyone else use their UVerse Remote DSLAM's.

DSL won't work at all over copper at that distance. You may be 21Kft from
the CO, but you're less than 8K feet from the local RT. Since most digital
services are on fiber from the CO to the RT, that distance doesn't matter
much. What matters most is how many feet you are from the RT, what shape
your copper media is in (which you cannot control), and how many other
subscribers are sharing the RT (which divides available bandwidth among
them).

LLoyd