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Using cat5 to connect a phone line?

by sliron / January 30, 2012 3:17 AM PST

I have an extra cat5 cable running from my comcast modem (internet and phone) in my study room to my family room across my house. Can I use this cat5 to connect a phone set in my family room to the modem, so I do not have to run a twisted pair over the house?

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All Answers

Best Answer chosen by sliron

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Yes you can,
by mrmacfixit Forum moderator / January 30, 2012 8:21 AM PST

Your Cat 5 ethernet cable is only using two pairs to carry the data traffic to and from the modem.
That leaves two pair spare.
You can use one of those pairs to carry the voice traffic. Telephony only uses one pair of wires.

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It's the same . . .
by Coryphaeus / January 30, 2012 5:07 AM PST

All telecom cable is twisted pair. The only difference is that Cat-5 has more twists per inch.

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Extra cat5 cable = 4 phone lines :)
by cw00dward007 / April 25, 2012 12:30 PM PDT

Your standard phone line only requires 2 pair (tip and ring, i think they're called). The cat5, being that it's extra has 4 unused pairs of wires inside the outer jacket (usually blue). The little plastic connectors on the end of cat5 are called RJ45 jacks. Instead of RJ45, get RJ11 jacks to put your cat5 wires in (you will need a crimp tool). These are the smaller, but similar jacks you find on pretty much all phone lines. Since you are in Colorado, if you need help, check out this company for Denver telecom work in your area and I believe they are very reasonable. Might even do it for free, i don't know. I think my cousin got help from them with his office or something. Good luck, it's a lot easier than it sounds, but definitely try and borrow the crimp tool if it's just for one job!


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I must have missed something here,
by mrmacfixit Forum moderator / April 26, 2012 8:21 AM PDT

where did you get the "Since you are in Colorado" from?


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