Author Topic: Wiring home telephony & ADSL - someone help me untangle this mess  (Read 814 times)

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Offline TheAmmoniacal

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The phone line enters the house in the attic, goes through the ceiling and down into an outlet that looks like https://dms-cf-02.dimu.org/image/032uLXHtFoV9?dimension=1200x1200.

Which is wired like in the first picture, from what I can gather - only the red and blue wire is connected to anything, they go down to the outlet on the first floor - which is wired like the second picture.

I can't make any sense of this wiring. Do I just need the red and blue wire for both telephony and ADSL? Red + blue into the VDSL splitter, phone and internet out?

I just want to place the modem on the second floor (outlet in the first picture).


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Online sokoloff

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Re: Wiring home telephony & ADSL - someone help me untangle this mess
« Reply #1 on: July 14, 2018, 02:49:37 am »
DSL and voice can come in on the same (ideally twisted) pair of copper wires and, in fact, that’s the most common deployment that I see.

Typically, the line comes in on a pair, is split to a jack with no filter that the ADSL modem hangs off of, and the rest of the line goes through an optional filter and then out to the POTS(voice) phone jacks.

Hope that helps you figure out what you’ve got. I didn’t try to puzzle out the wires on your pics, as I assumed your main question was whether they came in on one pair. Yes.
 

Offline AG6QR

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Re: Wiring home telephony & ADSL - someone help me untangle this mess
« Reply #2 on: July 14, 2018, 02:51:40 am »
The color code may vary somewhat, but yes, for one phone line with ADSL, the phone company typically runs one circuit to the home, using just two wires. 

The voice line is carried at audio frequencies, while the ADSL is modulated at higher frequencies.  The splitter is a low pass filter for the phone side, and usually straight through for the modem outlet.  The modem has an internal high pass filter.
 

Online helius

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Re: Wiring home telephony & ADSL - someone help me untangle this mess
« Reply #3 on: July 14, 2018, 02:58:51 am »
Telephone wiring is added onto over time, developing these complicated patches and loops. A single subscriber line is a single pair, but many jacks are wired for multiple-line operation, and may be combined with other systems like alarms or intercoms, and the 4 pairs in a cable can be all mixed together like this and sometimes used in different "directions" within the same cable.

It's quite likely that if the cables are as in the pictures, that the pairs are no longer twisted correctly for ADSL to work. I would suggest that you use the existing cable from the "second floor outlet" to the entry point (called the DEMARC) as a fishline to pull a new cat5, and punch it down without all that loose wire running around. Then from the ADSL splitter, feed the filtered phone line back into the outlet and splice that into the existing cable to the first floor.
 

Offline Ice-Tea

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Re: Wiring home telephony & ADSL - someone help me untangle this mess
« Reply #4 on: July 14, 2018, 04:05:01 am »
It's quite likely that if the cables are as in the pictures, that the pairs are no longer twisted correctly for ADSL to work.

ADSL will take an insane amount of abuse. Wouldn't worry too much...
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Offline CopperCone

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Re: Wiring home telephony & ADSL - someone help me untangle this mess
« Reply #5 on: July 14, 2018, 05:28:20 am »
You can add some telephone line filters to it, they are kinda cool. It's basically a little box with a big passive filter network inside, might help save stuff from lighting... since you already are working on it
 

Offline Mr.Elendig

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Re: Wiring home telephony & ADSL - someone help me untangle this mess
« Reply #6 on: July 14, 2018, 10:20:18 pm »
As seen on TVIRC™
« Last Edit: July 14, 2018, 10:38:36 pm by Mr.Elendig »
 

Offline BradC

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Re: Wiring home telephony & ADSL - someone help me untangle this mess
« Reply #7 on: July 14, 2018, 10:32:21 pm »
It's quite likely that if the cables are as in the pictures, that the pairs are no longer twisted correctly for ADSL to work.

ADSL will take an insane amount of abuse. Wouldn't worry too much...

While true, every bit of "abuse" reduces your SNR and consequentially potential line speed. Within reason, the cleaner, the faster.
 

Offline coppice

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Re: Wiring home telephony & ADSL - someone help me untangle this mess
« Reply #8 on: July 15, 2018, 12:16:56 am »
It's quite likely that if the cables are as in the pictures, that the pairs are no longer twisted correctly for ADSL to work.

ADSL will take an insane amount of abuse. Wouldn't worry too much...
ADSL is very tolerant of some kinds of abuse and very intolerant of others. Any minor audio crackling during voice calls can mean the line won't function reliably for ADSL. Water ingress into cables can also be a killer, so a lot of people get trouble with their ADSL in wet weather. If you are well separated from the exchange you may find lifting a phone makes the ADSL connection drop. On the other hand, twisting the pairs is highly overrated. :)
 

Offline bw2341

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Re: Wiring home telephony & ADSL - someone help me untangle this mess
« Reply #9 on: July 17, 2018, 04:34:09 am »
I'll give it a try...

I'll start with the following assumptions:
- The second floor left jack is working for telephone while the right jack does not.
- The modem was installed on the first floor by the ISP's technician.
- You now want to move the modem to the second floor.
- All voice and data services are working properly.
- There are no other phone jacks.

As you said, the incoming blue and red wires are being fed down to the first floor. On the first floor, they are punched down on the first position of the upper terminal block. This is feeding the left jack and the beige modular cable. The beige cable feeds the DSL splitter with the combined voice and DSL signal.

The filtered telephone output of the DSL splitter feeds the black modular cable that is plugged into the right modular jack. Since the white and red wires are punched down on the first position of the lower terminal block, the white and red wires have filtered telephone service.

On the second floor, the white and red are punched down on the first position of the upper terminal block. This should give you working phone service on the second floor left jack. The right jack should have no phone service.

The yellow and red wires on the second floor are a mystery. Are there any other jacks in the residence? Do they work? If so there could be another complication.

The first floor jack has the modern color codes on the terminal strips that are the same as those for Ethernet connections. It's clear that they directly connect all eight wires to each jack. The second floor jack does not have the color codes. If the right jack works for phone service too and there are other working jacks in the residence, the second floor jack must be built differently.

If it has internal bridging connections, the second floor jack module may be unsuitable for the modem. Look in each jack and count the number of contacts. If there are less than eight contacts per jack, there must be bridging connections. Use a multimeter in resistance mode to check for common connections on the unused lower terminal strip. If both jacks work for phone service as connected right now, the jacks are bridged together. You will need to physically swap the first and second floor jack modules to move the modem.

If the second floor jack is not bridged and works the same way as the first floor jack, moving the modem is relatively simple. Pull the second floor white and red on the upper terminal strip and move them to the first position on the lower terminal strip. Cut the blue and red connection to the first floor and punch down the incoming blue and red on the first position of the upper terminal strip. Now the upstairs jack should work like the original first floor jack. Connect the modem and test the data and voice connections. The only difference would be that the first floor right jack is active for phone service while the left jack is unconnected.
« Last Edit: July 17, 2018, 05:08:39 am by bw2341 »
 

Offline TheAmmoniacal

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Re: Wiring home telephony & ADSL - someone help me untangle this mess
« Reply #10 on: July 21, 2018, 04:43:35 pm »
Thanks for the replies everyone, I have now successfully rewired the internet and phone - and learned the basics of how ADSL works.  :)
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Offline MarkF

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Re: Wiring home telephony & ADSL - someone help me untangle this mess
« Reply #11 on: July 22, 2018, 02:35:05 am »
Consider a POTS Splitter. It has both screws and jacks.
This is what I did for my parents and it works very well.  No need for individual filters at each phone.
I don't know where you can get them in your country.
 

Offline Waterman

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Re: Wiring home telephony & ADSL - someone help me untangle this mess
« Reply #12 on: July 30, 2018, 05:51:48 pm »
Telephone wiring is added onto over time, developing these complicated patches and loops. A single subscriber line is a single pair, but many jacks are wired for multiple-line operation, and may be combined with other systems like alarms or intercoms, and the 4 pairs in a cable can be all mixed together like this and sometimes used in different "directions" within the same cable.

It's quite likely that if the cables are as in the pictures, that the pairs are no longer twisted correctly for ADSL to work. I would suggest that you use the existing cable from the "second floor outlet" to the entry point (called the DEMARC) as a fishline to pull a new cat5, and punch it down without all that loose wire running around. Then from the ADSL splitter, feed the filtered phone line back into the outlet and splice that into the existing cable to the first floor.
Also depends on how old your wiring is. Our house has two phone lines with the DSL being on the second number. None of the wiring for the phones/DSL is on twisted pairs. It all is on 4 wire cable. Pairs are line one, red/green and line two, black/yellow. if we went with U-verse, it would need rewiring to Cat 5 or better wiring to the new modem. Once it leaves the Modem, it is on Cat 5. There are filters at every phone jack except the one where the modem is on.
 


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