[vox-tech] Carrying telephone signal over ethernet

[Ted Deppner]

On Thu, Mar 18, 2004 at 03:26:48PM -0800, Larry Dieterich wrote:
> 100BaseT runs on two pair. No?

Yup.

> And isn't the twisting supposed to eliminate crosstalk?

It does eliminate noise that hits both wires, as it's designed to
eliminate noise on that pair.  If a pair is open or you wire across
pairs, you get noise all over the place.

That said, a good wiring job with Cat5 has never produced any noticable
crosstalk onto a POTS line in my experience.

Just keep your eth TX/RX (pins 1,2 and 3,6) on one pair each, and stick
pots on it's own pair.  The only "tricky" bit is how you stick in the
cable and pull it out.  For ease, rj11 and rj48 crimps are cheap, and a
female-to-female rj11 on either end will get things working with a
minimum of fuss.  A step up would be to install rj48 and rj11 button
jacks on the wall.

-- 
Ted Deppner
http://www.deppner.us/