atcomsystems.ca/forum Forums Wiring - Telecom Carriers - Trunks & Services Cabling Telephones Systems Wiring Single CAT 5 Cable for both Voice and Network possible? 3 pair vs 4 pair at 100mpbs ?

Hello

I’m in a situation were I have a house that does not have conduits and impossible to run new wire.

Every room in the house has exactly 1 CAT 5 cable which forces me to choose between having phone vs having a Network connection.

I was reading in this forum that someone said you don’t need all 4 pairs on the CAT 5 but rather it technically uses 3 pairs.

My question is:

1. Can I use this CAT 5 cable for both voice (1 pair) and Data (3 pair)?

2. Is the 3-pair CAT 5 at speed at 100 Mbps? (I’m assuming that 1000 gigabit speed does in fact use all 4 pairs?)

3. Which pair or pin combination can be removed from the CAT 5 and still have it function at 100Mpbs data network? If I could get a little more information on this configuration, it would help me out a lot!


Thanks for your help.

It's not reccommended that you do this, but it can be done. Use the white/blue pair for the voice jack and use the white/orange and white/green pairs for data. I have been faced with the same situation and was able to get it to work just fine.

In summary:

White/blue goes to pin 5 of the voice jack;
Blue/white goes to pin 4 of the voice jack;

White/orange goes to pin 1 of the data jack;
Orange/white goes to pin 2 of the data jack;

White/green goes to pin 3 of the data jack;
Green/white goes to pin 6 of the data jack;

The white/brown pair is not used.

Yes I have done that also. Works fine, but like Ed said it is not the correct way to do things.

Thank you both for the response.


What type of speeds are you able to get with this modified wiring setup?

For example: 1Mbps/10Mpbs/100Mbps/1000Mbps?

I actually only need 1 single pair for voice because its just in my house.

Are you saying when my 2 options are either:

1. Have all 4 pairs

or

2. Have 2 pairs (removing brown pair and blue pair)?


In other words, could I get a better speed if I use 3 pair instead of 2 pairs in the event that I need to use one of the pairs for phone?

Please let me know, I sure do appreciate you help.

I can't say for sure, but since cable modem and DSL can't provide more than 10Mbps, that's all that I have ever expected. I am doing this with CAT3 cable at my home. I have never tried to do any better since we really don't do any networking at my home that requires much speed.

Remember that 10/100 only uses the white/orange and white/green pairs anyway even if voice wasn't in the equation. There's no way to improve speed by adding a third pair; it's two pairs for 10/100 or four pairs for 1000. The fourth pair (white/brown) could be used for a second line or DSL, but that's really pushing your luck.

It would be interesting to see what type of speeds you could get if you used a CAT6 A cable but only use the White/Orange and White/green Pairs.

I am hoping that I could get at least 100Mbps.

You are right that Cable or DSL is not any faster than 10Mbps however if you are getting into streaming HD video across your home network to your various TV with Home theater or these media streaming devices such as

and also plan on getting Security Cameras, streaming music and a lot other home automation IP based project like this one:
netstreams

I'm also trying to share hard drive space across the network. It seem that the 100 would be a lot better if possible.

I must say that having internet at any speeds in a room that was one thought to be hopeless is a great thing!

Thank you for your help.

You will be fine for 100 on CAT5 cable. Remember that my 10Mbps speed is on CAT3 or lower cable. Wiring is a lot more tolerant than you think.

Using CAT6 cable wouldn't increase your speeds at all; that is determined by the hardware at either end. Like the others have said, two pair for data will get you 10/100, based on the fact that you're using two pair. You need all four pair dedicated to data for any higher speeds (assuming you have higher speed network cards, routers, switches, etc.). One thing to watch for in any event: your hardware may have to be manually set for 10 or 100 or whatever mbps, as well as duplex (half or full). I've seen many instances where simply using the "Auto" setting doesn't work.
Bill

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