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#44755 11/10/04 11:07 PM
Joined: Nov 2004
Posts: 3
Junior Member
Received some cable for a job today it was CAT 5E 2 Pair, have never seen it before. Is it cost effect and how much is it used. only using one pair for the job.

#44756 11/10/04 11:43 PM
Joined: Oct 2003
Posts: 6
Junior Member
Hi Polar Bear-

Cat 5e 2 pair is usually used for data communications specifically ethernet and token ring. These data networks usually use one pair for data receive and the other pair for data transmit. I have seen this type of cable come in 2 pair and 4 pair. The pairs are twisted together tightly to prevent crosstalk interference between pairs. Usually for data-comm infrastructure 4-pair cable is used since you need a minimum of 2 pairs if something goes wrong with one pair of wires you still have 2 spares to fall back on, before you have to re-pull the run. 2-pair cable can be pulled to save money but in the long run it could be risky.

Since you are using only one pair this is most probably used for analog voice communications of some sort.

Hope this helps -

#44757 11/11/04 12:57 AM
Joined: Dec 2003
Posts: 886
Never saw cat 5e in two pair. I have seen cat 5- 2 pair used for patch cords. I didn't think it was possible to maintain the cat 5e characteristics without the other two pair.

You can use it for 10/100 baseT ethernet as only two pairs are used but you will have problems trying to figure out how to terminate it.

Since you are only using this for voice it's no big deal and that's probably about all it's good for. If you are looking for cost effectiveness look at cat 3 for voice but I suspect somebody was trying to unload that stuff real cheap.


#44758 11/11/04 11:37 PM
Joined: Oct 2003
Posts: 156
Do not think you could even call 2-pair Cat5E. Couldn't be used for 1000Base T systems at all (4-pair technology). Certainly does not meet TIA/EIA-568A-5 standard for Cat5E. Should be OK for POTS, but I wouldn't trust it for ethernet.

Edited spelling errors

[This message has been edited by dereckbc (edited 11-11-2004).]

#44759 11/12/04 06:17 AM
Joined: Jul 2003
Posts: 394
It is almost always false economy to not provide for expansion. For our building backbone, we pulled 12 strand fiber when we needed two. Today,it's all in use on some of the IDFs

#44760 11/12/04 10:32 AM
Joined: Oct 2004
Posts: 16
Your Cat 5 CAN be used for 10/100M Ethernet- The standard refers to the number of twists per inch, and wire gauge. We used to use this when wiring 10M building networks. I have this in my house for my 100M network.

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