We support Areas:

Can one use the unused wires in a network CAT 5 (and 5e, 6) cable for a telephone connection?

The wires in a network cable should not be untwisted more that 1/2" for CAT 5/5e cable and 1/4" for CAT 6 cable. Furthermore, separation of pairs of wires from the other pairs should be minimized as the geometry of the overall cable is important for performance. A network cable should not be bent sharper than 4 times it's diameter. If you are in the US, the ring voltage on the telephone line will probably disrupt the network. In otherwords, I don't recommend it. If the network cable is not going to be used for networking, A four wire, telephone RJ-11 plug can be plugged into an eight-wire RJ-45 jack and the RJ-11 plug contacts will match the unused wires (10/100BASE-TX network, not 1000BASE-TX) in the network cable, if the jack is wired correctly. If it isn't wired correctly and a computer, etc. is connected at the other end, one can expect to see smoke at the other end. I used CAT 5 cable for the telephone lines going to my shop/office, but the cables are terminated with 4-wire RJ-11 telephone jacks and are not shared with my network. One can put four, 2-wire telephones on one 8-wire CAT 5 cable; however the ring voltage may occasionally disrupt any dial-up MODEMS using the same cable. I've seen that happen on 120 foot cables.


Tags: wires network cable voltage line network networking unused wires network cable jack

ZIP Codes Covered:

10026 10025 10029 10024
10128 10021 10023
10019 10021 10022 10020 10036 10017 10018 10016 10001 10016 10011 10010 10011 10003 10009 10014 10012 10013 10002 10007 10038 10280 10006 10005 10004