Cat5 cable use for telephone signal

I've used CAT-5 (solid core) wire for wiring an extra phone outlet before. It actually worked quite well. In regards to which pair of wires to use, just pick a pair - any pair will do.

 

If you want to be able to use the cable for data also (possibly at a future date) you might want to follow the standards. Blue/blue-white for the primary phone line and Brown/brown-white for the second line. They even make some adapters that you can plug into standard RJ45 jacks to break out the phone lines. Hubs and 10baseT NICs interface fairly well but switches and 10/100 NICs sometimes ground out the extra leads creating some fancy jack wiring needs.
If you've examined phone jack wiring carefully you'd see that a phone cable would plug and lock into the center of a RJ45 jack and use the blue pair without modification. I believe phone wiring is also called Cat3 wiring so Cat5 is actually a better wire to use.

 

more and more houses are being wired with CAT5 and CAT5e for phones. if you run your own cable through plenum spaces, be sure to get plenum grade cable in order to both meet building/fire codes as well as protect yourself from the risks associated with non-plenum cables emitting toxic fumes in plenum spaces if there's a fire..

 

Also, using CAT5 significantly reduces crosstalk when the cable carries multiple phone lines.

By the way, can someone tell me what the “e” designation is (CAT5e)?

Regards,
Wayne A. Pflughaupt

 

Wayne,

"e" = enhanced.

 

Thanks, Bill. I guess the next question has to be, enhanced how?

 

Some of the older "cat 5" cabling had too much crosstalk to support gigabit ethernet. Cat 5e was designed with gigabit ethernet in mind.

It really isn't relevant to a home environment...most businesses aren't running gig ethernet over copper. I run it over fiber at my company. You'll probably only be running 100 mb at home and that'll work over any cat 5 cable.

 

Thanks for the info, Michael.

Cheers,
Wayne

 

Phone lines are Cat1. Cat3 is data cable as well -- for 10BaseT networks. Most telco guys around here use Cat3 in businesses (where cross-talk could be a bigger problem) but still use Cat1 in residential. Plenum cable is used not only in plenum spaces (i.e., cold air returns) but vertical runs as well (i.e., between floors). The downside to plenum is that it's roughly twice the cost of regular Cat5. We pay around $60 for a 1000' roll of Cat5e, and $140 for a 1000' roll of plenum. Another downside is that it's a little harder to work with too. My favorite brands of cable (in order) are: AT&T, Comscope and Belden.

When I remodeled the front room, I ripped out all the old telephone cable throughout the house and replaced it with Cat5e. The Cat5e is home-runned to the spare bedroom closet into an in-wall multimedia center that lets me patch in data or phone services as needed. Makes moving computers and telephones around really nice. I ended up with two drops per bedroom, two drops in the kitchen, two drops to the garage, and 8 drops in the front room (yep, I'm a certified geek).

Curt
Senior Network Engineer

 

heh curt, sounds like youve been to the leviton certification classes too.
the cat5e is more tolerant to outside noise, and has a better grade of materials, resulting in less crosstalk and higher signla transfer. there is also cat5e+ which is the 350mhz kind, and it is the best of yet, unless you want to try and wire cat6.
the cat5e is much better than basic phone lines though, the twisting of the pairs in the cat5 wire is also what reduces crosstalk. try stripping back about 1ft of cat5. you will notice that the different pairs are twisted at different rates to lower the crosstalk between the individual pairs in the cable as well.
the industry standard is like metioned before, blue and blue/white for main phones. on a cat5 jack the next pairs outside would be the green and green/white for a 4 line plug.

 

Could someone help me out?

Can I use ONE cat5e run for ethernet (4 wires) and phone
(2 wires) to a room? Or will the phone interfere with
the LAN?

 

I've been running 2 phone lines and a 100tx LAN on a single Cat5 with no problems for a year. I also share with S-video and audio at times.

 

Thanks Steve! That's good news! Would you happen to know
why my cable modem to my NIC is connecting at 10BaseT?
(Don't have a router/LAN yet, just one PC) I think the NIC
is set to autosensing and supports 10/100. The light on
the card indicates 10 baseT. If I try and force it to
100 baseT, it doesn't work. Just want to make sure this
won't limit my LAN to 10 baseT in my new home... Thanks
again.

 

Not sure if I read your question correctly Henry, but I'm pretty sure the CAT 5 requires all 8 wires in a CAT 5 cable, not 4. You need to run 2 individual CAT 5 runs to your location, 1 for Ethernet, and it's RJ-45 connection, and 1 for the phone line, and it's RJ-11 connection.
I'm not sure how Steve was able to pull off what he said, but he's smarter than I.
Also, the actual color pairings for CAT 5 to voice, is Blue / Blue-White and Orange / Orange-White (Not brown, or green).... Of course it doesn't really matter though, just depends on if you want to follow standards or not.
Here's a link to white papers on the topic:
http://www.levitonvoicedata.com/lear...strat_apdx.pdf

 

from several sources on the web, ethernet seems to only
need 2 pairs. although most of the time you do see 8
wires in ethernet cable, 4 wires are unused. As far
as I can tell.

 

They are unused but some 10/100 cards and switches will ground the extra wires. 10-base-t devices usually leave them open. So , depending on what you're plugging in , you might have to break out the phone connections before the jack or use one of the commercial plug-in adapters that separate the phone and data connections.

 

Hey Steve,

So could you point me to a link with these adapters?
It looks like the builders route the cat5 to a outlet
that I can't really tell if it supports phone only, or
phone and ethernet. It looks wider than normal phone
outlets... Would you know?

It'd be cool if there was a connector I could
plug into that outlet to have both an ethernet outlet and
a phone outlet...

Your help has been really great! Thanks!