Ok, I have had DSL put into my home. It's from SBC and I'm having a
ton of problems. I want to put in my own Demarc unit but I have a
questions. Let me first tell you my home was built in the 80's, is in
Southern California. Here is the situation. The wire coming in from
the street has ten wires in it. 5 white and 5 colored. The lines in
my house have six wires. These are setandard if you will....3 colored
wires and then three white wires with the corresponding colored lines.
Anyway, the wire from the street to my house is going to a piece of
equipment (About hald the size of a deck of cards) that had two screws
on one side, two on the other and then a single screw that was
connected to a grounding wire. Anyway, everything I'm reading talks
about Demarc boxes and lines having a green and red wire. This is not
the case for me. What the heck do I connect to what? Do I only
connect the "two live" wires from the street to the new Demarc unit or
do I connect all ten. Is the colored line the "green" or the "red"?
Any help would be appreciated. Thanks.
If you know color scheme and what Tip, Ring, Sleeve means.
You have two live wires and rest are spare pairs coming in. You have 3
phone jack outlets in the house? I reckon you installed filters for DSL?
Inside your house, if the 3 pair is standard (called station G) wire,
the color code would be:
First Pair White with Blue (tip) Blue with White (ring)
2nd Pair White with Orange (tip) Orange with White (ring)
3rd Pair White with Green (tip) Green with White (ring)
Note: Tip is Positive (+) Ring is Negative (-)
You need to insert a DSL filter (using one pair) for the phone line
that your DSL Service is piggybacked on. Easiest place to do this is
at or near the Demarc Box. (That way, only one filter needed). The
fillter keeps the hissy DSL noise off of your phone line.
Otherwise you would need to put a DSL filter at each phone which is
usually a pain. Don't forget about alarm interfaces, satellite
receiver telephone connections and answering machines. They need the
The wires coming from your CO (central office) may or may not follow a
standard color code. One or more will have POTS (Plain old telephone
service on it) depending on how many phone lines installed in your
house. One (and only one) phone line, will have the DSL line
installed. This needs to pass through (unfiltered) to your DSL
utilization point. Typically, this is the jack where you plug in your
A telephone handset and a DC voltmeter would be handy service tools to
have at this point.
The device you describe is an older style protector block. You can hook
up your inside wiring to this block, or you can call your phone company,
and ask that they install a new Demarc box, which will replace the old
protector block. This will allow for easier testing in the future, and
your telco should not charge for this service.
The Demarc is the responsibility of the telco, and marks the demarcation
point between telco responsibility and homeowner responsibility for the
phone wiring. The newer demarc units provide facilities for telco testing
of the line, and for the homeowner to easily disconnect inside wiring
for testing. The demarc also houses the protection devices for the phone
Your existing protector block should have a pair of terminals for the
incoming line, a terminal for a ground connection, two screw-in protectors,
and a pair of terminals for your inside wiring. If installed right side up,
the line should be on top, and the inside wiring on the bottom.
You will need a 3/8" nutdriver to work on this protector.
I should note that it is a good idea to disconnect the incoming phone line
at the demarc when working on inside wiring, unless you like getting shocked
with 90-100 volts AC if the phone should ring. You can use a clip lead to
short across the incoming line, which will busy out the phone line.
Your active phone line from the street will be coming in on one of the
5 pairs of wire in your drop cable. The standard wire colors are as follows:
pair X tip color/ring color (white/blue)
(example: white or white/blue stripe is tip,
blue or blue/white stripe is ring.
The pairs are twisted together, they should
remain that way, and the pairing between an
tip conductor and it's corresponding ring conductor
should be maintained.
In old style "quad" wiring, tip is green,
ring is red, with black and yellow used for the
second line, or for external ringers, or power
supplies for dial lights.)
pair 1 white/blue
pair 2 white/orange
pair 3 white/green
pair 4 white/brown
pair 5 white/slate (grey)
pair 6 red/blue
pair 7 red/orange
(etc.. 5 tip colors: white,red,black,yellow,violet.
5 ring colors: blue.orange.green.brown.slate.
used as a 5x5 matrix for 25 pairs.)
Your active phone line should be on pair 1, but it may be on any of the pairs,
depending on the past history of phone lines into that house.
The telco is responsible for connecting this pair to your demarc. You are
responsible for any wiring on your side of the demarc.
Your individual phone jacks should be wired with the green/red wires on the
jacks connected to the white/blue wires in the cable, and the black/yellow
wires connected to the white/orange wires. This will allow you to connect
2 lines at the demarc, and use standard two line phones or splitters at
each jack without further rewiring. If you only have one line coming in
from the street, you should leave the second pair disconnected at the
demarc for future use, buit go ahead and wire the jacks.
If you are installing a DSL splitter at the demarc, you want to identify
which cable goes to the jack where your DSL bridge will be connected, and
identify if any other jacks are on the same cable. The easiest way to
test this is to disconnect one cable at a time until the DSL jack goes dead,
and then check to see if anything else went dead in the process. Make note
of which jacks these are.
You can then install the splitter between the demarc and all of the non-DSL
jacks, leaving the DSL jack directly connected to the demarc, or to the
DSL terminals of the splitter. You will need to use a filter on all phones
connected to the DSL jacks, but not on the ones connected to the splitter.
Another option is to use the third pair of the cable going to the DSL jack
to add a new jack, and use that one for the DSL, while connecting the others
to the splitter. You may need to splice that pair at any jacks between the
demarc and the final jack if the wire is cut. Use the Scotch jelly bean
type splices available at Radio Shack or your telecom supplier.
The third option is to not use a splitter, and use filters on every non-DSL
jack in the house. This is the easiest solution, requiring no rewiring.
-- Welcome My Son, Welcome To The Machine --
Bob Vaughan | techie @ tantivy.net |
On 25 Aug 2005 19:18:43 -0700, email@example.com wrote:
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