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  • Help me solve the mysterious issue for my DSL line

Hey everyone, this post is going to be a bit long, weird and complicated, I'll try to explain the problem in detail with some pictures, so please bear with me.

I've been having an issue with my DSL line for more than two years now, the main culprit is electrical interference, which is heavily tanking down my SNR. I am with IDM 4mbps. The first thing I thought of doing was to install an external phone cable from the phone box, directly to my room, been procrastinating and left it untended for a long time since the modem was syncing at full speed but with critical SNR. We have our own two stories building, there is a shop at the ground floor, the weird part is when this shop electricity is on, it will further increase the interference. This shop is sharing the same electricity meter with the house. Five months ago I noticed the modem is syncing at 3600 downstream rate to maintain a stable connection with 6.0db SNR, so I decided to install the external cable, I used a high quality D-Link CAT 6, directly from the phone box, went inside an isolated tube with no other cables, this tube goes upwards to the rooftop, then to my room, installed the exposed part inside a plastic/electrical tube to protect it from sunlight. There was some improvement, the modem now syncs at full speed but still with critical SNR. Another weird thing is that there are literally two modes for the SNR that keeps switching every once in a while:

Mode A:

Which is heavily affected from both, state and sub-power electricity. When electricity is off, I have 21db down/14db up, 6.0db down, same for up when electricity is on. Switching the modulation from ADSL2+ to G.dmt increases downstream SNR by 2 to 3, therefore 8 to 9db.

Mode B:

Which is significantly less affected from electricity, however this one varies between state and sub-power, on state electricity, the lowest it goes down to 12db, highest is 16db, while on sub-power, the interference is minimal. Also on this mode, the upstream SNR is always 8.0db which is lower by 6db compared to mode A. I am not sure if the central is switching me between two profiles back and forth, nevertheless, electrical interference is destroying the SNR for both modes.

We have a complete box/patch panel which contains 10 telephone lines installed inside the building, Ogero offered it as a compensation back in 1996 because they wanted to install a cabinet (the small/grey one) in our yard, which is 10 meters away from my room.

That is the box from the outside which contains 10 phone lines. The four punched down pairs are the two active phone lines. That is from the inside.The first pair, white and blue is the one I am using for the DSL, the white and yellow pair is the one for the shop at the ground floor, it has no DSL activation.

That is the phone box where the lines are distributed from. Here you can see the installed CAT 6 (the grey one) cable. So I started to think outside the box, I did cut the other phone line, as expected, nothing changed. When I switch off the electricity meter, the interference is gone. When I terminated the line in my room, I got electrocuted twice when I touched the bare copper, I had to wear a pair of shoes, this confirms that there is electricity flowing within the cable.

The question is, how is the line still picking up interference after the external installation? I called Ogero (Before Kreidieh took over) and they told me that if it is electrical interference, you have to bring an electrician, I talked with two electricians, one told me that the interference from the shop is only a coincidence, so I didn't bother talking with him again. The other one told me that he has to come and take a look. However he has the usual trend of, I'll be there at 2:00 and no one will show up. I talked to a guy who, as he claimed, experienced in DSL installation, he was speechless and scratching his head when I told him about the external installation.

At first I was okay with the line handling the 4mbps, but now with the upcoming speed increase, it will rely on how much your line can handle, so I might not see any increase due to the low down SNR. Also with the upcoming FTTC project, it will still rely on copper, so I have to fix this problem for good.
By all means check the "electrocution" issue before anything else. It could be just bad luck as while the phone is ringing, you get 100+ volts on the phone line, and hence you could get a nice jolt jolt if you're barefoot. On the other hand, it could be far more serious if some live electrical wire is in contact with the phone wires, and that would be a safety hazard that needs to be attended to immediately.

Having said that, disconnect the whole internal telephone wiring from the box, keeping the external cable hooked (you won't get the line tone anymore if you pick up the handset) so that the wiring goes from the box to your modem only and test.
@InVader, I do hope that the phone was ringing back then but I doubt it since the SNR result is an indication of an electrical interference.

There is no internal wiring at all, only a single CAT 6 cable going directly to the modem. As for how the handset is having a tone, I looped the signal externally inside the house also using CAT 6 to another room and terminated it to a junction box to give the handset a signal.
I am not sure I understood your exact setup with respect to the phone wiring, in addition to having 2 boxes. The simplest test you can do is disconnect the white and yellow wires from Ogero's box, place your modem next to the box if possible, and connect it directly to the box. That would give you an idea about the problem being before or after the box.
What's the white cable running along with the telephone cables (Ogero box)? In general, it's good to keep a distance of 10-15 cm between data and power cables.
You can ignore the first box in the first picture, the second box is the one where you can distribute the lines directly from it. The white cable is the one for the shop I mentioned, which is connected to the yellow and and white pair. Those white cables are the ones Ogero installed, I had the same one for my line (blue and white) which used to be inside the walls, I cancelled that completely and installed the CAT 6. Just a reminder, I did cut down the white cable that is connected to the shop but it didn't help at all.

I forgot to mention that I also did that long time ago, I brought down the UPS, the modem, a 1 meter CAT 6, hooked the short cable directly to the box, the other end to a junction box and directly to the modem. Same thing, waited for the blackout, SNR sky rocketed, sub-power came and the SNR went down again. I also tried it when the state electricity was on, turned the electricity meter off, therefore cutting the power for the entire house, SNR instantly increased. The cable is far away from any power cables and isolated now. I am sure that the electricity is sabotaging the SNR, but it is not a direct contact with power cables, it is something else which I still don't know, that is what baffling me, it is like a riddle.

Does your SNR increase drastically when the power is off? you have to test that quickly before sub-power is on.
Its probably unrelated but I had alot of packet loss issues and SnR not being very stable. I was afraid I might face the same electricity interference issue with sub power specially that both phone and sub power are cables too close together and the sub power box was right next to the where the phone cable passes And it was very noisy in there making me suspect it was producing alot of interference.in many spots and it appeared electricity cycles effected my connection stability aswell.

In the end it turned out it wasnt an issue from my side and after ogero did some maintanence somewhere in the area I have a perfectly stable connection and an SnR that can handle 20Mb+ speeds hehe.

After asking some experts and researching about it a bit electricity shouldnt have much effect on phone line stability.
@iron, You mean that you used to have low SNR when electricity is on and after Ogero made the maintenance, your SNR increased?

I feel like I have to contact Ogero again but I have to convince them that I made everything possible from my end. I heard that the customer support is better now with Kreidieh in charge.
Already tried that, same results.

Another weird thing I forgot to mention in the original post, in mode A, the modem always syncs successfully from the first try, even though it has inferior SNR, while in mode B it always syncs from the second try and fails in the first. Also tested that on two modems and both did exactly the same.
Get yourself a AM radio tune it to 612Khz
(not 1700khz) & just keep your ears open as you move around your
neighbour & you'll find the source of interferance
For more info google about REIN "Repetitive Electrical Impulse Noise"
@Khalil7, I recently read about REIN and SHINE since I searched a lot about electrical interference, however the interference isn't coming from a certain device. You know of any efficient electrician? If so please PM me.

Can you test your SNR in the period where a power cut will occur? will there be any major difference? I am starting to suspect that the problem might not be from my end, there is a manhole five meters away from the house that has all the phone cables passing through, interference might be occurring somewhere there. I did contact Ogero about that and they asked me to send my landline number to thepeople@ogero.gov.lb but didn't receive any reply.
I might suggest something else, but it is physically a bit hard. Try to get wire clips, disconnect rest of your line in basement from box, and clip in basement accurately to line going out of building.
Then you need difficult setup: running ups + dsl modem + laptop. Try to run ur internet in basement and check for SNR. If it is much better - it is inside building. If it is not - Ogero side issues most probably.
@nuclearcat, You mean the closeup direct test? I did that long time ago, I wrote about it in post #5. Is that what you meant or something else? that test made me believe that the issue might be from the underground cables, but still, when I turn the electricity meter (which is inside the building) off, the interference is gone. When the backup power generator is on, the interference is on again but a little less severe, even if you turn the power switch off (the switch that'll give backup power) the interference is still there as long as the power generator is turned on.
Yes, but did you disconnected part of phone line going to house? even you hook before house but kept wires going to house connected, if noise induced in line in house will affect cable on all its length

you mean you turned your electricity meter only?
1)try to run modem just on ups (disconnect ups from mains totally and no ethernet cables as well)
2)If you have many circuit breakers, try to shut some parts of house and try to turn off all appliances, to if there is any changes
Yes, I completely eliminated the cable going up the house, connected the cable coming from Ogero box directly to the modem, so there was nothing else between the modem and the phone cable. The old cable that is going inside the walls is eliminated from the basement now, from it's root. I don't see how it'll still induce noise!

Yes, the electricity meter "ساعة الكربا" when I shut it down, the interference is gone.
1) I tried that, only on the UPS's power without plugging it to the wall socket, same results.
2) Inside the house there is the power switch that will switch the power between main and sub power. If I cut the power down completely from that switch, therefore cutting the power from the house, thus no appliances are on whatsoever, the interference is still there, but if I shutdown the electricity meter from the basement, the interference is gone. It is a freaking riddle :(
Is it possible wires of telephone and mains going in same tube from basement to house?
No, it is only a single CAT 6 cable with a thick jacket going alone in an isolated tube. I also used the white and blue pair which has the most twist per inch, this will further help in reducing noise.
Hello, after reading I have few suggestions, first let me write what I did understand:
- Electricity OFF = NO Interference
- Electricity ON + Basement Meter Down = NO Interference
- Electricity ON + Basement Meter Up + House Meter Down = Interference

The Cat6 cable is installed in an isolated environment and each phone has a filter, and because the result of this installation was the same as the result when the modem was connected directly to the Box it means that the Cat6 part is not the cause.

So here is what I'm suspecting is happening:
1- I suspect that the Ogero cable coming from the street cabinet to the building Box could be installed just next to the electrical wires in some place (It could be like 1 meters or less where the 2 cables are close to each other)

2- I also suspect that there is a power leak (Cable installed between Basement meter and House meter), this power leak could be caused by someone stealing electricity from your house (anything is possible), to Verify this simply get a clamp meter, measure the pulled Amps at the Basement Meter while the House meter is down, it should be 0 Amps

Best of luck
@anayman_k7, Hey, thanks for the suggestions. True, that is exactly what is happening. For your first suggestion, I will leave that for last because it is hard to make Ogero cooperate with the issue. I tweeted Mr. Kridieh twice "god bless this man" after 20 minutes he forwarded my tweet to the Ogero team who asked me to send them my landline number, I think that after they figured out that I am with a private ISP, they refused to cooperate and stopped responding, however it is their responsibility and only they can check on the underground cables. As for the second suggestion, that is intriguing, I'll get an electrician "which is also a hard task" to check on all the power cables in the building.
You can do both tasks by yourself, the first one will not be definitive but follow Ogero cable, maybe you can find it visually, as for the second, just get a clamp meter, shouldn't cost more than 10$ and measure the amps by placing the clamp around 1 cable only before or after the basement meter, by 1 cable I mean 1 of 2 cables that forms the wire cable (black / red)