Help me wire my telephone line.

**DUD** · 07-21-2006, 11:05 AM

I only have one line, so I can't help out on this one. Bill

**vaking** · 07-21-2006, 11:09 AM

Unlike networking cables - telephone signal is AC. In an AC wiring there is no positive or negative. In other words - I don't think it matters. You use the 2 central pins always, which pin is which is unimportant.

**JSUPreston** · 07-21-2006, 11:13 AM

I used to install basic KSU phone systems and still install phones whenever I move. Unless someone one here knows more than I do (which is highly likely), I've found that as long as you are consistent with the color of the wires, you shouldn't have a problem. This includes DSL. By the way, have you considered placing a DSL filter at the demarc? Then, you don't have to deal with those dongles all over the house, and you have a jack that is dedicated to DSL.

**Waper** · 07-21-2006, 11:32 AM

Thank you all for replying.

DUD: This is about a single line, as I said above I will only use pin 3 and 4.

vaking: That's strange, as far as I know telephone lines are DC circuits, at 48 VDC when telephones are on-hook, and drops down to about 3-9 VDC when a telephone is off-hook. When the telephone rings a 90 VAC RMS @ 20 Hz is applied by telco to make the phone ring. If you're on a single line you should see two wires coming from NID, one is TIP(+) and the other is RING(-). If you have a multimeter you can verify this by measuring DC current at both TIP and RING when a telephone is off-hook --it must be off-hook to close the DC circuit allowing electricity to flow--.
Even with AC current there is a HOT/LIVE wire and NEUTRAL wire and GROUND and although it doesn't matter how you wire your phone or AC outlet you end up with a non standard installation which may cause problems in the future when upgrading or maintaining your installation. Anyway it's a matter of opinion and following codes.

JSUPreston: Yes, that's close. I don't have access to NID so I asked telco guys to run a cable from there, then inside my house I'm going to install a DSL splitter, so I can have two dedicated lines, one for DSL and the other for voice communication, still I will install DSL filters at each analogue device, and since I don't have a protector installed at NID I'll use surge protectors at home.

Thank you all, but please if someone knows the answer to my question let me know.

Best regards.

**DrAzTiK87** · 07-21-2006, 11:54 AM

When wiring an analog line it doesn't really matter. It will work either way but the standard is 3 Ring 4 Tip.

**offthemark** · 07-21-2006, 12:50 PM

Waper, are you outside the US? If not, your local phones may work differently.

**Waper** · 07-21-2006, 01:20 PM

DrAzTiK87: Thanks, 3=Ring 4=Tip is how I always knew it until I got confused because of my DSL splitter and filters, they indicate otherwise, so I searched for more information and found out that some say that 3=Tip 4=Ring not the other way around. I just want to learn which is the standard USOC or whatever it's called

I know it will work either ways, but as I said it will be a non-standard installation, it may cause confusion in the future when upgrading or maintaining, besides -believe it or not- some telephones are still tip/ring sensitive (not auto-sensing).
Anyway, I still want to know why information conflicts about this subject?

offthemark: Yes I live outside the states and where I am there are no codes, standards or regulations, you just follow the "****-yeah" method and if it doesn't blow it's a go.
Since there are no standards here I chose to follow the US ones, just to follow a standard so when I pick up a wire at the far end of my house I know what it is for without having to guess, test or mess up something, besides I buy must of my electrical equipments from the US so it seems reasonable to follow US regulations and codes.

**DrAzTiK87** · 07-21-2006, 02:47 PM

Will DSL signal be present at all jacks or one single jack??

**Waper** · 07-21-2006, 02:57 PM

Well, since my run is from Demarc to a DSL splitter so I suppose the DSL signal will be only available at the ATU-R/CPE jack of the DSL splitter. Then from the phone jack of the splitter will be another run to the rest of the house for normal voice communication.

I just noticed your edit

"If you are wiring the splitter you would wire it up as 3 Tip 4 Ring because the splitter requires a different cable/pair be used for the voice and data."

I'm sorry I don't understand, the splitter has three jacks, one for line (from demarc), second for DSL CPE (to DSL CPE) and the third is phone (to the rest of the house). All three jacks have that strange reversed polarity, so in other words the phone jack at the splitter is not like the rest of the phone jacks hence the different pin assignment. So what if one decided to plug their phone to that jack, it will different.

Also don't forget that I said my DSL filters (have 6 of them) also have this reversed polarity, if you look at their male plug with prong down you see Ring as 3 and Tip as 4. This will lineup if you plug it to the splitter since both are reversed but if you plug it to a standard female jack you see that red wire connects to green and green connects to red.

**DrAzTiK87** · 07-21-2006, 04:59 PM

Wire all three jacks from the splitter 3 Ring 4 Tip.

If you have a splitter you don't need filters. If filters are used instead of a splitter, a maximum of five or six telephone devices with filters can be used before they begin to excessively degrade the DSL signal.

Do you have filters or duplex adapters which will allow you use one jack for both the DSL connection and a voice connection.

**Waper** · 07-21-2006, 05:17 PM

Well yes that would be the standard wiring I always knew, although the splitter clearly indicates otherwise, what made things worse is that the wiring of my filters which come from a completely different manufacture are the same as the splitter, that's why I started this topic to get things clear.

I sent an email to the splitter manufacturer's technical support asking for explanation about this.

By the way, take a look at this, I found it while researching this topic:
http://www.cisco.com/univercd/cc/td/...rn/1347401.pdf

This document is regarding (Cisco 575 LRE CPE) you'll see that the pin assignment for this CPE female jack to telephone wall jack is the same as the splitter, but however they clearly indicate that a rollover cable should be used in order to correct the pin assignment, in other words reverse the reversed pins

As for your question about why use filters if I already have a splitter, well, this is because filters act as a bidirectional gate, meaning that they block high frequencies from phone line -with DSL signal- to analogue devices, and also they block those frequencies from the analogue device and forbid them to enter the phone line --think of it as a backdoor--, this is to ensure smooth operation in case the phone sends high frequencies back to the line which could be picked up by the CPE as DSL signal.

Also there is an issue about attenuation, when you pick up a phone (goes off-hook) the voltage drops to low levels, this affects the whole phone circuit and could weaken the DSL signal and cause errors and retries. Installing a DSL filter at each analogue device helps reduce this. (I don't know why, but this is from real life experience)

I know the splitter should also forbid high frequencies coming from house from passing to the DSL jack but adding filters at each device is for precaution. (again a real life experience one).

**DrAzTiK87** · 07-21-2006, 05:30 PM

The document you posted is for a DIGITAL PBX.

**DrAzTiK87** · 07-21-2006, 05:39 PM

Originally posted by Waper

As for your question about why use filters if I already have a splitter, well, this is because filters act as a bidirectional gate, meaning that they block high frequencies from phone line -with DSL signal- to analogue devices, and also they block those frequencies from the analogue device and forbid them to enter the phone line --think of it as a backdoor--, this is to ensure smooth operation in case the phone sends high frequencies back to the line which could be picked up by the CPE as DSL signal.

Also there is an issue about attenuation, when you pick up a phone (goes off-hook) the voltage drops to low levels, this affects the whole phone circuit and could weaken the DSL signal and cause errors and retries. Installing a DSL filter at each analogue device helps reduce this. (I don't know why, but this is from real life experience)

I know the splitter should also forbid high frequencies coming from house from passing to the DSL jack but adding filters at each device is for precaution. (again a real life experience one).

Info from some docs I have.

Using filters isolates the DSL service at each individual telephone jack, but the DSL signal is present on all the jacks. That's an additional physical connection for each telephone device. Interference on any phone jack may impact DSL speeds or could cause DSL to stop functioning entirely. Because the filters are connected to the line cord for each device

Using a splitter completely isolates the DSL service from the telephone line, so the DSL signal is not present at each telephone jack. A splitter also limits how many connection changes are required to complete your DSL installation and is not normally subject to incidental physical damage. DSL signal from a splitter is much more isolated from sources of interference, resulting in optimal DSL speeds.

**Waper** · 07-21-2006, 06:39 PM

Thanks for pointing that out, I didn't notice at all! Well, this is a relief as we can dismiss this document and wait for an answer from the DSL Splitter technical support about why they reversed polarity!

Thank you for posting this additional information, I agree with you completely. As I stated above installing filters at each device while using a splitter at the main entry point is not to block DSL signal at each device as it should be already blocked by the splitter it's to reduce attenuation and to prevent high frequencies coming from "devices" back into the main network.

Notice what I have posted above "I know the splitter should also forbid high frequencies coming from house from passing to the DSL jack but adding filters at each device is for precaution. (again a real life experience one)."

One of the installations we made relied only on a splitter but still when a certain telephone was picked up it would attenuate the signal in the whole network thus causing DSL line to drop at the CPE! Installing a filter solved this problem.

That's not a mandatory thing, just an extra precaution.

Help me wire my telephone line.

Help me wire my telephone line.

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Footer Ad