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Posted By: Tiger Networking Residential PCs - 08/10/06 06:11 PM
I've wired a home with CatV 4 pair wire and the homeowner wants to network his PCs with this wiring. I'm using one pair for the home phone line with DSL. I believe I can get a triple jack for phone, cable & data.

My question is: Are the remaining three pairs enough and what are the connections.

Thanks,
Dave
Posted By: trobb Re: Networking Residential PCs - 08/10/06 07:12 PM
While they are enough, you must avoid it if at all possible. Where I work, they used two pairs for the data line, and one for the phone (from the same cable)... and now every time you pick up the phone you hear data signals. If you can prevent untwisting the wires more than 1/2" you will prevent most crosstalk, and also the problem I just described.
As for the pairs: blue and white/blue are phone; orange and white/orange (one pair) with green and white/green (another pair) are data, send and receive, brown and white/brown are not used but should be terminated so they don't act as an EMI/RFI antenna.
If you look at the jack, with the pins at the top, blue (phone) will be the middle pair, and the pins to the right and left of it will be another pair (they straddle the blue pair), with the other two pairs on the far ends. The far right pair is not used, and the far left & middle (split) pair are for data.
Posted By: giddonah Re: Networking Residential PCs - 08/10/06 07:14 PM
You can run 10mbps ethernet off two pairs. Just get a standard ethernet connector and wire up #'s 1,2,3, &6.
http://www.ertyu.org/steven_nikkel/ethernetcables.html

Whether you'll get interfearance from the other signals is probably debatable, but some people have gotten networks to run off some pretty shady wires.
Posted By: trobb Re: Networking Residential PCs - 08/10/06 07:18 PM
The 1/2" is per Cat5e specifications, and to be fair the data lines had a tap on them running elsewhere, so who knows what was going on...
Posted By: golf junkie Re: Networking Residential PCs - 08/10/06 08:27 PM
In hindsight the owner should have wired the house with CAT5. Now your best option is wireless network.

I wouldn't mess with trying to do what you are proposing.
Posted By: gfretwell Re: Networking Residential PCs - 08/10/06 10:43 PM
I have a phone line on a CAT5 with data and I haven't noticed the noise but I am deaf.
(Too many years around line printers and check sorters)
The problem I have heard of is ring current spiking the LAN and causing errors. I don't have any "bell" ringers so I doubt it is a problem. You probably wouldn't notice the errors in a residential setting anyway. If you were in an office where the LAN was banging hard all day and the phone never stops ringing it might be significant.
Posted By: gfretwell Re: Networking Residential PCs - 08/10/06 10:46 PM
The only caveat is you will be limited to 100mz ethernet since the 1gb uses all 8 wires. Do you have the jack diagram? You will be splitting out the phone pair so you need to get the right pins for the pairs left.
Posted By: trobb Re: Networking Residential PCs - 08/11/06 10:52 PM
Yeah, my thing is I tend to be "by the book" too much, and don't bend when I should. In a commercial, always-on, connection the crosstalk could be hellish, but in a residence you probably could get away with it.
Posted By: gfretwell Re: Networking Residential PCs - 08/12/06 01:23 AM
If you are selling data you have to follow the book. I was only relating what I have got away with when the only one who can complain is me.
In a residential setting, as long as the customer knows what the exposure is he can try it.
Posted By: Tiger Re: Networking Residential PCs - 08/20/06 12:25 PM
Thank you very much for your replies.

Dave
Posted By: brianl703 Re: Networking Residential PCs - 10/05/06 09:24 PM
The IEEE 802.3 specs are available free for download from IEEE.

If you read them you will discover that 10baseT ethernet was designed to operate in the same cable with existing analog phone lines.
Posted By: gfretwell Re: Networking Residential PCs - 10/06/06 04:30 AM
Yup 10BaseT and 16mz Token Ring will both work on Cat3
It is 100BaseT and beyond that starts using the capabilities of Cat5
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