Re: POTS and Ethernet over CAT-5 Cable

Hello Brian,

Is it possible to use some of the extra wires in CAT-5 cable to run a
POTS line or two?  I heard that Ethernet only uses two of the eight
wires.  Is this true?  If so, seems like I could run 3 POTS lines in
addition to my Ethernet over my CAT-5 home network.

There will be a serious current spike whenever the receiver is taken off hook or placed back. That may or may not cause packet losses on the data pairs. Ringing can also generate 90V or so and an open loop phone line can run up to such voltage levels as well. So if you accidentally miswire something ... bzzzt.

Utilities also have their rules and some may not endorse such wire mixing. Anyway, personally I wouldn't do it so I ran two CAT-5 to every location from the central closet. CAT-5 is cheap. Plus now it's future proof in case there comes a day when the other two pairs are being used for the data link.

If this is correct, are there any jacks available that would make this
easier than cutting open my cables?  Thanks.

You have to cut the cables anyway to connect an RJ45. In this case you'd just have to cut the sleeve back some more. But again, I wouldn't do it.

Regards, Joerg

http://www.analogconsultants.com
.

Relevant Pages

  • Re: POTS and Ethernet over CAT-5 Cable
    ... The ringing voltage isn't going to ... The use of POTS with ethernet is per specification ... > I should have mentioned that I am in the US, so POTS takes two wires. ...
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  • Re: POTS and Ethernet over CAT-5 Cable
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  • Re: POTS and Ethernet over CAT-5 Cable
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