Yes, but you are pushing it. The extended will gigo (Garbage in, Garbage out) on you. As I see it, you have two major problems to deal with. The first is the 25 pair cable is shielded, which means your UTP is no longer UTP, because you now have added capacitance due to the shielding. The second is the 25 pair has, at best, maybe a half twist per inch. Crosstalk is going to be a factor.

Having induced ringer voltage in the same line will also cause intermittent problems with low data rates or dropped data. My suggestion would be to either run a Cat 5 or 6 cable the entire way or, do yourself and your client a favor, and place a fiber. You'll be glad you did.

Rcaman

Americom, Inc.
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