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[Excelsior]

Hello there, my first post and I'm already asking for something!  I've been reading around some issues and wondered if anyone could suggest anything.  Just this Monday, our broadband fell over (Sky, MYELL exchange).  This was early evening; no resolution by the time we went to bed.  Tuesday it mysteriously reappeared.  Tuesday evening, gone again.  After hours on the phone to Sky, they decided to send a new modem out.  Throughout this the modem was apparently on the exchange, and we could talk to it locally, but no Internet connectivity.

I understand that it is possible for RF interference to knock out a broadband signal in wires (both wired and wireless wasn't working, so it was a problem at the socket).  What I realised last night was that the broadband came back after we'd gone upstairs - and after I'd turned our living room halogen lights off.

Now, those lights have sometimes caused issue for our cordless phones but never, ever had any problems with them and the Internet.  That said, tonight there was a glitch without the lights being on.  So perhaps our modem is dying after all?  It's a Netgear from Sky, which I've always had faith in.

Throw into this mix the fact that we think out exchange is going FTTC imminently.  I think we might be on ADSL2, but I'm not sure and I understand that as with FTTC if your exchange is enabled it doesn't mean you are?  I also understand that ADSL2 is more sensitive to noise than ADSL1.  Am I able to find out what we're on, could it have changed quietly over the weekend so that the lights coming on produces enough interference to clobber the ADSL feed? 

It was very pointed last night - any level of lighting, no signal.  Lights off, signal was back almost immediately.  And yet it's never been like that before.  Any suggestions welcomed - might a better shielded RJ11 lead help?  Thanks your help.

[snadge]

Hi there, welcome to KITZ - youve certainly come to the correct broadband forum for help

some of the more experienced "experts" will be along soon hopefully, meanwhile I will try to offer up some advice:

firstly if you get us your line stats it will tell us a bit more about your line and we may be able to tell you if your on ADSL1 or ADSL2/2+
to get your stats (assuming its a Netgear DG834GT) click this link and user the username:admin + password:sky (if that fails try admin / password)

copy & paste your line stats in like so:

ADSL Link   Downstream   Upstream
Connection Speed   17861 kbps   945 kbps
Line Attenuation   26.5 db   15.0 db
Noise Margin   8.4 db   10.9 db

It sounds like your halogen lamps are at fault, sounds like a faulty Inverter (possibly) which controls the power to the bulb (I think) because it happens all the time when they are on, or bad wiring or something. Your best getting these looked at because as you know it can affect all digital services, wifi, dect phones, broadband, sky tv....etc

Have you read the REIN page on this site?

it could be the REIN is going directly into the modem 'through the air' or nearby internal extension wiring as a form of RFI (Radio Frequency Interference) , or if not, through mains as a form of EMI (Electromagnetic Interference)

1. are they near the router?
2. do you use any extension cables from socket/filter to router? (if so does this pass near the router?)
3. do you have other BT sockets around your home?

see here on how to access the test socket, install the filter and router in there, but first grab your stats before you do that so we can get a before and after picture (stats on current setup then stats whilst plugged into the test socket) - this will help us identify if your internal wiring may be adding to the problem.

4. when you remove the faceplate to access the test socket, are there wires going into the back of the faceplate? (if you have other BT sockets around the home then you will have) if so can you confirm that the wire on terminal 3 is connected? (this is a known culprit to pick up REIN and introduce it into the line, you dont need it, remove it and try your lights and see if you get same result.

please answer questions above and post up before test socket and in test socket stats for comparison, like I say; some of our more distinguished members will be along to help soon

[burakkucat]

I don't know if I'm distinguished enough for snadge but I'm here, just looking in before I go and reacquaint myself with my bed.

It most definitely reads as if a fault has developed with your halogen lighting system and, as a result, significant RFI is being transmitted -- either in free space or via the mains wiring -- to completely "knock-out" the broadband signal. (I am wondering if your near neighbours -- if they have a broadband service -- are also noticing an effect on their service(s).    )

Once you have gathered all the information that snadge has requested to see, I would ask you to perform just one more experiment, please. With your modem/router connected into the test socket of the NTE/5A, note the modem's statistics. Now turn on the suspect lights and re-determine the statistics. I think it will prove illuminating (pun intended    ) to compare the two sets of results.

Please excuse me, as I now have something important that requires my attention . . . 

[snadge]

yeah, I agree with B'cat ,  it sounds like a really strong source of rein doesn't it? if its completely knocking it out until its turned off and your neighbours broadband, wifi, wireless phone or TV may be affected - ive seen a few instances of this sort of thing affecting neighbours (treadmills) and even an entire street once (faulty tumble dryer <- BT had to locate this one) - be interesting to find out...

anyway, we look forward to your results tomorrow.

[BritBrat]

I had issues with Sky's DNS servers the other day, changed to openDNS and everything worked.

My computer was connected OK but the one set auto failed, so worth a try to test if it is that.

Although I don't think this is your problem as you seem to be using a Sky router the other thing that sprang to mind is if they have turned on MER at your exchange and dissabled the other protocols.

It was very pointed last night - any level of lighting, no signal.  Lights off, signal was back almost immediately.  And yet it's never been like that before.  Any suggestions welcomed - might a better shielded RJ11 lead help?  Thanks your help

But like others have said it could be faults in your lighting system.

[Excelsior]

Good morning all.  Not at home unfortunately so I can't do a lot at the moment, but last night from memory my up speed was just shy of 800, down speed was around 1500.  Yes, I know, I know, but we're in the countryside and 4km from the exchange.  We have some sort of under-pavement connection to the BT system, recently had the pavement dug up and the wires now start at ground level and go up into the house along our wall - but what was done a while ago.

Now then, line attenuation - fro memory that was around 58 /21 ?

The noise margin was interesting.  That I looked at with the lights on and off, complete with wife aggro for being obsessed with it (!)  That went from 0 / 11 to something like 13 / 11 with the lights on.  Unfortunately I haven't had to delve this deeply into my modem stats for a while so I am uncertain as to what that suggests.

What is also becoming apparent is that our modem is becoming unstable in and of itself - my wife couldn't connect to it earlier this morning at all, had to reset it.  So it may well be that it's on its way out and has become susceptible to interference as a result.  Could it perhaps be failing to compensate for noise on the line or something?  Incidentally, there are no ominous hisses or anything coming from the lights, they look stable, so nothing seems to have changed there.  Plus we are decidedly uncertain about there the transformer(s) is/are to be able to look at those.  No bulbs have blown or anything.

In terms of testing the master socket - we don't have one.  I've looked at the primary box we use previously and there's no test socket.  Couple of other extensions but they're not in use.  Suffice to say this house has held a few surprises for us, so what's been set up in the past is really anyone's guess.  As I say, until recently there hasn't been a problem, we're just waiting with baited breath for FTTC to come along - if they actually turn it on for us.  Seem to be a lot of Openreach vans around, but it may just be because I'm looking for them!

A neighbour at the other end of our row did mention when we asked that his BT connection seemed wobbly, but he's a fair way down the road from us and we have old thick walls.  Our cordless phones are no worse and the Wifi signal itself is fine, so perhaps it's an EMI issue if it isn't just the modem dying?

I will look up what MER is - it's annoying that you can't contact exchanges direct, but we do know it's not reported any outages, nor is it particularly heavily used.

[BritBrat]

Do you have another router?

If so you would need to get user details from the Sky router to use one but it may be worth a try, my bet is if you contact Sky about a fault they may send you a new router.

[snadge]

no router stats then?  would be great if we could see them. 

does your master socket not have a split front where you can screw the bottom half off? if not then I dunno what the crack is with the ring wire on the older LJU type master sockets (if they have ringwire or not - maybe someone could let us know?), you could remove the front of it and check to see if the ringwire is connected on terminal 3 and report back, the only wires you need are 2&5 - wire 3 is known to pick up the REIN and introduce it into the line.

if your lights are giving off REIN then its something thats become faulty in them, first place to start would be its power source.

if your line attenuation is 58db then you should be achieving in the region of 3000 down, im surprised your getting 800 up on that connection mind? - anyway, its not ADSL1 connection your on.

your router can actually be flashed with either the Netgear official firmware or DGteam firmware and you can manually set your noise margins and ADSL1/2/2+ , aswell as run monitoring tools like Router Stats and DMT tool, as your line is long you dont have much lee-way to be able to raise your noise margin in an attempt to give you more stability, your source of REIN sounds pretty intense and needs addressing, I dont think ADSL1 and a shielded RJ-11 will do much to save you from it, but by all means try it.

when you turn your lights on the noise margin should drop to 0 if its knocking the broadband off, then back up when they are not on. if your noise margin is currently 11db then thats why your only getting 1500 down , DLM has raised your noise margin in attempt to make your line more stable from the dropouts its detecting.

(Noise Margin drops when their is noise on the line because the margin between the signal and the noise becomes less, to counteract you can 'raise' the noise margin higher in attempt to make it more stable, but as you can see that doesnt even work for you)

If it were me I would be turning off the lights completely for a while so I can run monitoring tools on my flashed Netgear so I can see whats going on without them - this will also give me a chance to see if the router is faulty.

 if you use wifi then you could have interference or trouble connecting to that and thinking its the modem/router thats at fault.. if you cant connect to it then you should plug in the LAN cable to be sure its not a poor wifi reception.

[Excelsior]

Good evening.  So, these are my precise figures with the lights off:

ADSL Link Downstream Upstream
Connection Speed 1326 kbps 796 kbps
Line Attenuation 50 db 28 db
Noise Margin 15 db 12 db

Lights on:

Connection Speed 1326 kbps 796 kbps
Line Attenuation 50 db 28 db
Noise Margin 5 db 12 db

So the downstream noise has actually dropped a lot.  Connection to the exchange seems to hold, but no data throughput.  Interesting?  What does this mean exactly?  Any way I can pin down where the interference might be originating?  Thanking you.

[BritBrat]

Any way I can pin down where the interference might be originating?  Thanking you.

Yes with a radio:
http://www.kitz.co.uk/adsl/rein.htm

[snadge]

your 50db line is capable of 5000 (5Mb) sync rate or thereabouts
DLM has set a 15db Noise Margin as its detecting dropouts and thats why you get the slower speed

the connection holds because the noise margin was set high enough to hold it, it went down 10db to 5db...it needs to drop to 0db for it too lose connection, default noise margin on sky is 7db (6db most other ISPs use)

no data throughput AT ALL..? is that whilst connected via LAN cable to the router? when diagnosing you should always use the LAN cable because like I said in previous post if your using wifi it may be getting affected too and that will get in the way of correctly diagnosing whats happening.

if the lights arent kicking it over now then its because DLM has raised the Noise Margin further than previously and its giving you enough "distance" between the noise and the signal OR there are other sources of noise and when these are active (lowering the noise margin) when the lights come on it kicks it over..

[Excelsior]

Ah yes I'd read that.  Not sure we have a portable one, but I'll have to see what I can do.  So odd it's just started out of the blue.  That noise behaviour is clearly there from my stats.  Spot on. 

Snadge, understand what you're saying in terms of testing it cabled - but it impacts on out Sky HD box's Anytime + and that's a wired connection to the modem.  So it isn't just the wi-fi that's getting clobbered, it does seem to be on the modem.  We get the odd little bit of data through, but web page for example is a no-no.

At what point would you expect it to be unusable, you sound surprised we're not getting something at 5db?  The other night the connection did get lost with the lights, I do wonder how stable our modem is.  New one is on the way from Sky, so we'll see what happens when that gets here.

I might try a firmware upgrade.  Any way to tell when we switched to ADSL2 at all?

Liking this forum software by the way, puts mine to shame!

[snadge]

just its always best to diagnose via LAN - for e,g, the router could be working perfectly but on wifi you may not be getting anything through or its slow and you could blame the router/modem - when in fact it could just be the wifi signal your having trouble with due to location. I know its obvious your having problems with noise on the modem but like I say it still best to plug it in via LAN when running tests etc... everyone else will tell you the same thing, I know its not always practical as I have that problem myself with a PC on Wifi...lol...

as your getting a connection sync you should be getting some throughput, web pages should work somewhat? if your not and your CERTAIN its not your wifi thats struggling with the throughput also , then its errors on your line from the noise, but if it was so bad that it stopped all throughput then its unlikely the router would have been able to make a sync with the exchange (which it has)

 - your noise margin dropping to 0db or so is when you lose connection because the noise level and signal meet, some routers can hold a sync just below that but most likely it will drop around the 0db mark

you are currently on ADSL2+ because your upstream speed is 796k - you wouldnt have that on ADSL1 (448k)
you may fair better on ADSL1 as it will not try to use the higher frequencies like ADSL2+ does...  but if normally when you turn on lights and broadband will not sync until they are off then i doubt it would make much difference , however here we see you holding a sync with the lights on, so I wonder if your noise margin has been the default of 7db when its been happening (dropping 10db like it does from 7db will kick this over until the lights go off) but now DLM has upped your margin to 15db to make it more stable so a 10db drop takes you to 5db, which it can still hold a sync.

any chance you can plug it in via LAN now and see if your throughput and web pages start to work? - if still same then its high error count on the line, be caused from the noise....

on that connection (sub 1Mbps actual throughput) Anytime+ will be hit hard with or without noise I would think as less than 1Mbps is not enough to stream movies i would think, not without some buffering here and there)

hope this helps

whats your forum by the way?

[Excelsior]

Right I might try it linked up tomorrow night then.  The forum is an old Ikonboard one - it's pretty quiet and not exactly state of the art but I keep it for nostalgia to some extent!  Have a look at the site - Star Fleet

[snadge]

hey its good, nice and bright website, forum looks canny too - im sure I saw that Star-Fleet when I was younger, I recognize that robot