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Q: Ethernet Wiring ( Answered 5 out of 5 stars,   3 Comments )
Subject: Ethernet Wiring
Category: Computers
Asked by: marc10-ga
List Price: $5.00
Posted: 20 Jan 2003 19:14 PST
Expires: 19 Feb 2003 19:14 PST
Question ID: 146291
I am looking for some ethernet wiring alternatives. I am attempting to
connect a router to a computer that is in another room. I cannot
simply attach a ethernet cable from the router to the computer due to
aesthetic/physical limitations. However there is a telephone line that
runs from the router to the other computer. I am wondering if I can
piggyback off the telephone line and use it for a data connection? If
so, how? (Both the router and the computer are expecting a standard
ethernet RJ 45 input.)

Below is a link to a photo of the telephone jack I have near the router.
There is another identical jack next to the computer I am trying to connect to.
Taking a close look at the phone line, I can see that only certain
wires are used for the phone, the rest (brown, white and green) are
sitting idle. Those unused wires is what I was hoping to take
advantage of.

As can bee see in the photo, I also have a cable TV jack. I use that
to receive cable television. That jack is unused at the router but is
in use near the computer (it is connected to a TV). However If there
are options to piggback off that wire also, I would like to hear them.

Please let me know if you need clarification.

Clarification of Question by marc10-ga on 20 Jan 2003 19:16 PST
i am aware of wireless alternatives, but would like to explore
hard-wired options first.

Request for Question Clarification by maniac-ga on 20 Jan 2003 19:34 PST
Hello Marc10,

Are there four wires free on the phone jack? If so, you should be able
to use them for at least 10 Mbit/sec Ethernet. I did something like
that in my previous home to share our dial-up line with the kid's
computer upstairs. I would provide references to the proper plugs,
wiring, etc.

Request for Question Clarification by bio-ga on 20 Jan 2003 19:37 PST

There are solutions for home networks that use a standard phone line
for ethernet data transfer (broadband Internet connection sharing and
file/printer sharing), but they are not cheap (over $100 or so). Would
this be acceptable for you?

Subject: Re: Ethernet Wiring
Answered By: sycophant-ga on 20 Jan 2003 22:08 PST
Rated:5 out of 5 stars
An 802.3 10baseT connection only requires two pairs, which according
to your photo, you appear to have.

By adding another RJ45 socket to your faceplate (where the black coax
wire seems to be coming out) and connecting the Pin 1, 2, 3 and 6, you
should be able to make a working 10baseT patch.

Wiring should be as so:
Pin 1 - White/Brown
Pin 2 - Brown
Pin 3 - White/Green
Pin 6 - Green

The should be numbered on the socket, however, if you they are
numbered left to right, when looking at the open end of the socket.

Please be aware that this wiring method will only be able to carry
10Mbit ethernet connections, not 100Mbit, and depending on the length
from one end to the other and cable quality, may not operate as
efficently as a properly installed 4 pair cable.

For reference:
Note the wiring is for 100baseTX grade wiring, but indicates pairs not
necessary for 10baseT.

Search Terms:
10baset wiring 2-pair


Clarification of Answer by sycophant-ga on 20 Jan 2003 22:18 PST
Also, if you are connection the router and computer directly together
without a hub, you may need to have a crossover connector. You can do
this in one of two ways:
1) By wiring one end of your in-house cable as a crossover:
Pin 1 - White/Green
Pin 2 - Green
Pin 3 - White/Brwon
Pin 6 - Brown 

2) Create a crossover patch cable:
As detailed on this page:

I would suggest the second option as being the better one, as it gives
you more flexibilty to expand on your network later - you can add a
hub at one end of your cabling and connect more than one computer.
marc10-ga rated this answer:5 out of 5 stars and gave an additional tip of: $5.00
Excellent answer. I have not had a chance to complete the project and
test the results, but the in-depth response will make it easy for me
to do.

Subject: Re: Ethernet Wiring
From: jm7197-ga on 20 Jan 2003 20:16 PST
This solution will provide you with an RJ45 port at any electrical

If you want to use existing phone wiring for both broadband net access
and analog phone, you need HPNA.

here is a page from earthlink describing the process step by step
along with the products you will need.

a general websearch for "HPNA" will yield high results...  :)
Subject: Re: Ethernet Wiring
From: neteng78-ga on 27 Jan 2003 20:22 PST
HOOKED INTO THIS PHONE LINE.  If you simply plug in an RJ 45
connection into a live phone line, you will cook your equipment.
Subject: Re: Ethernet Wiring
From: sycophant-ga on 29 Jan 2003 00:39 PST
Re: neteng78's comments... 

As long as the other two pairs (currently used for phone line) are not
wired into the network plug at either end, and the phone and network
connections are clearly marked on each end of the connection, there
should be no risk at all. The two circuts are apart from each other
and should no have any cross-connection problems.

However, as neteng78 says, DO NOT plug a computer network into a live
phone connection. So it's fairly inportant that the two fittings are
clearly labeled. For safety's sake it may be worth putting RJ-11
sockets on the phone fitting - it should still be fine with more phone
equipment, but means much less chance of a mistake.


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