High Attenuation, noise on phone line

gingerjedi · Oct 08, 2007, 14:08:33

Hi, I've posted before (new account as I couldn't remember old one) about noise on my line and how it stops if I unplug my router, I have a Netgear DG834GT, new ADSLNation filters and my wiring is sound.

I have been on samknows and the number test says I am 1.89km from my exchange (sounds about right) and I should be able to get 4mb BB. (I only have 2mb) My router stats say SNR 20db down 25db up which is fine but my attenuation says 47db down and 25db up.

Isn't 47db a little high for someone who lives less than 2km from their exchange? Is this why my 2mb connection is 'noisy'?

Will BT just drop my profile despite there being an obvious problem or will they fix it?

Gary · Oct 08, 2007, 14:28:12

That attenuation is high but you have good SNR, could be the router displaying the wrong stats, have you tried the Quiet Line Test?

Unplug any extension phones, extension cables, answer machines or anything except the phone you will use to do the test. Plug a normal touch tone phone directly into the BT master socket (if you have a NTE5 socket) see the FAQ for a picture of this, Dial 17070, press option 2 (quiet line test) You should hear 'Quiet Line Test' and then silence, there should be no pops, clicks, whistles, buzzing etc. If there is noise on the line, make sure it's not your phones connection to the socket, give it a wiggle. If you are sure its the line making the noise then dial BT and report the fault, they should be able to sort it out. Rik will be along shortly with some sound advice as well, in case I have missed anything

Gary · Oct 08, 2007, 14:32:39

Also have you the ability to try another router to see if that makes a difference? Have a karma for starting again

Nick AJ · Oct 08, 2007, 14:41:18

Hi,

A couple of points. Are you sure you are on a MAX product and not a fixed 2Mb line. The SNR is so high for a MAX product.

If you are on MAX it could be you have a stuck BRAS profile - this will limit your connection and download speeds. A BT speedtest will give you more information.

Finally if the noise on the line goes when you unplug the router it's most likely a faulty microfilter, or a faulty router. Again as suggested borrowing equipment that you know works should eliminate the faulty item.

Nick

Rik · Oct 08, 2007, 14:48:58

Quote from: gingerjedi on Oct 08, 2007, 14:08:33
Isn't 47db a little high for someone who lives less than 2km from their exchange? Is this why my 2mb connection is 'noisy'?

Not necessarily, it's quite common for cable length to be double the straight-line distance, and if you have an aluminium line, that will further increase attenuation.

What Nick and Gary have told you is sound advice. If you can add your sync speed to the stats you have given us and, ideally, the results of a BT speed test, we can give you more detailed advice.

gingerjedi · Oct 08, 2007, 14:54:33

Off the top of my head I sync at about 2200kbps down and 286kbps so I dont think thats Max.

I did have Tiscali Max for a couple of months and that was unusable with very frequent drops in service hence why I have been reluctant to try MAX again, I have bought brand new ADSLnation filters which didn't change anything, 2 phones and sky box are filtered.

I don't have another router but I did try my old speedtouch USB modem yesterday which seemed ok but when I went back to my router that was ok as well so I am none the wiser! It's an intermittent problem that seems to raise its head once or twice a day, usually the phone line sounds 'fuzzy' and at the same time my SNR starts to drop then I lose connection.

I have tried the master socket but again it seemed fine at the time but was also fine when I plugged it back as normal again... ggrrrrr!

It's almost as if I get a static storm the lasts about half an hour or so then its fine???

When I joined IDNET I could only get 512k for the first couple of weeks as BT had dropped my profile as I had complained about connection drops when I was with Tiscali.

Gary · Oct 08, 2007, 14:58:06

Well being not on Max explains the high SNR if you have intermittent line noise and cant pin it down have you ever asked bt to do a check on your line as a voice fault? Also are your phone lines overhead or buried?

Rik · Oct 08, 2007, 15:00:29

You don't actually have a profile on a fixed-rate product, so that's not the issue. Try a BT speed test and see what that comes back with.

How many extensions do you have, and how are they wired, eg do they radiate out from the master in star topology, or are they 'daisy chained'.

My gut is suggesting you have something which is generating electrical noise nearby, so the way the wiring is laid out could be a big issue. It would be worth removing the ring wire from terminal 3 on all sockets, btw.

Nick AJ · Oct 08, 2007, 15:11:48

If it's a fixed product then you never will get anything better than 2MB. MAX will be your only option.

This is one of those faults that will take some tracking down.

Can you plug the router directly into the test socket, by-passing all the internal wiring? That will eliminate one potential problem area. If not it will be a good idea to plug the router into the incoming telephone socket and if possible disconnect any extensions.

If you then get problems with browsing, plug in a telephone into the filter, unplug the modem and see if you have any noise on the line. That would then indicate an external fault.

Does the problem occur at any specific time of day? Could it be a faulty central heating pump, especially one that's been off all summer.

If you can overcome the noise, then with your stats a good quality router should get you 4MB, maybe more if you ever went to MAX

Gary · Oct 08, 2007, 15:22:24

Quote from: Nick AJ on Oct 08, 2007, 15:11:48
If you can overcome the noise, then with your stats a good quality router should get you 4MB, maybe more if you ever went to MAX

That's not always the case BT generally define what you should be able to achieve speed wise by taking into account variables like line quality etc so if its old aluminium line of there are exchange issues he may not be suited to a MAX product at this time.

gingerjedi · Oct 08, 2007, 15:29:01

BT's own line checker says I should be able to get 4mb or more (when I had Tiscali Max I was getting 6mb... when it worked!)

I have removed the ring wire on all sockets, the 2 extensions are connected in a star topology, from the master socket one goes about 1 meter straight up and the other 2 meters to the right so there's no great distance involved.

Its not the heater pump, this has been going on for over a year now and during that time I have replaced both phones and filters, If I could replicate the problem so it was always present it would be a lot easier to solve but as I said before it comes and goes without warning, sometimes (but not always) I lose connection when the phone rings and sometimes the static noise is accompanied with a digital noise... it's as if I can hear the router trying to resync.

I'm starting to think my router is buggered but I have done loads of searches on Netgear routers and found nothing that points to this. I want to try Max again but I'm worried that if my line won't support a stable standard DSL connection then I don't stand a chance with Max. : (

When it does drop off the SNR goes from the 20's to 3 or below.

Rik · Oct 08, 2007, 15:29:57

Quote from: Killhippie on Oct 08, 2007, 15:22:24
That's not always the case BT generally define what you should be able to achieve speed wise by taking into account variables like line quality etc so if its old aluminium line of there are exchange issues he may not be suited to a MAX product at this time.

Generally, BT start by looking at attenuation. The OP is lucky to be on 2Mbps by those standards, 43db is the cut off point for d/s attenuation, so he should be on 1Mbps. That said, I live 2.26k straight line from the exchange, but have an attenuation of 56db, that's down to aluminium. I manage a 2500 profile, nonetheless, which is markedly better than my immediate neighbours, who can only muster 512k - 1M. It just goes to show how line quality and general noise levels affect the delivered, as distinct from theoretical, service.

Rik · Oct 08, 2007, 15:33:15

Quote from: gingerjedi on Oct 08, 2007, 15:29:01
When it does drop off the SNR goes from the 20's to 3 or below

You'd be very unhappy with Max, then as you'd be constantly re-syncing.

I wonder if you have one of the rare faults on your line, possibly an HR joint. The problem, as with all intermittent faults, will be to identify and locate it. Can you keep a diary, and note if there is any pattern to the issue?

If your Sky box is not in contract, I'd suggest disconnecting that to see if it helps.

Gary · Oct 08, 2007, 15:44:15

That's true my attenuation is 49db with snr of 6 going down to 3db at night maybe 2db, but my profile is 4500 and across the road a friend can only get 2mb fixed. and we are about 1.5 miles from the exchange

gingerjedi · Oct 08, 2007, 15:54:57

My sky box is mostly left disconnected so that's definitely not the problem.

If it is my line (big if) how can it be fair that a neighbour could have a good connection and because of my line quality I cannot? It seems BT are only interested in the phone service and as long as that works they couldn't care less.

Is there not a standard that they have to adhere to? After all I pay the same for my line rental as anyone else but with what seems like a lottery I'm one of the unlucky ones and there's nothing I can do

Just a thought... if I take a survey of my neighbours and find that they can all get Max without problem would BT be obliged to fix my line so I get the same?

Gary · Oct 08, 2007, 15:59:08

Quote from: gingerjedi on Oct 08, 2007, 15:54:57
My sky box is mostly left disconnected so that's definitely not the problem.

If it is my line (big if) how can it be fair that a neighbour could have a good connection and because of my line quality I cannot? It seems BT are only interested in the phone service and as long as that works they couldn't care less.

Is there not a standard that they have to adhere to? After all I pay the same for my line rental as anyone else but with what seems like a lottery I'm one of the unlucky ones and there's nothing I can do

Just a thought... if I take a survey of my neighbours and find that they can all get Max without problem would BT be obliged to fix my line so I get the same?

BT dont have to regrade lines unless there are serious issues with the voice side I would think, it is a lottery based on so many variables like how old your wiring may be compared with neighbours who may have only had phone lines put in recently, junction box conditions, if you have over head lines what noise they pick up, the quality of your internal wiring, to the master socket etc and I'm not sure BT would be obliged as you get a service now, which by their standards is probably deemed exceptable.

Gary · Oct 08, 2007, 16:03:26

Have you tried any of Riks Suggestions that are in the FAQ eg ringwire in the master socket etc? that can make a big difference, does your cabling run near any power cables internally is it shielded?

Rik · Oct 08, 2007, 16:05:04

Quote from: gingerjedi on Oct 08, 2007, 15:54:57
If it is my line (big if) how can it be fair that a neighbour could have a good connection and because of my line quality I cannot? It seems BT are only interested in the phone service and as long as that works they couldn't care less.

The only universal service obligation (USO) on bit is to provide voice, with data added at 28.8k.

QuoteJust a thought... if I take a survey of my neighbours and find that they can all get Max without problem would BT be obliged to fix my line so I get the same?

No. There's no requirement to provide ADSL at all, and you should be on a 1Mbps service, not a 2Mbps one, given your attenuation. If you make too much noise, you might find your line classified as unfit. If that happens, it's next to impossible to get ADSL again.

Best to try and identify a pattern, eg time of day, weather etc. That might give a clue as to the nature of the fault, and that would help you get it fixed.

You might find a different make of router would help, but there's no way of knowing.

gingerjedi · Oct 08, 2007, 16:22:33

Wow... it's about time that BT were brought into the 21st century and given a good kick up the arse! My dad live in rural Spain where he gets 13meg, I play on Xbox live quite a bit and a lot of people have 10meg & more recently 20meg connections through virgin media (cant get cable), people from the USA report 10meg as pretty much standard and in the far east I hear some people are on 50meg! I don't suppose BT will lay new cables anytime soon unless they are forced to.

What was that saying that best decribes Britain??

Mustn't grumble!

Gary · Oct 08, 2007, 16:23:51

Well maybe that saying is the problem

Rik · Oct 08, 2007, 16:26:37

Quote from: gingerjedi on Oct 08, 2007, 16:22:33
I don't suppose BT will lay new cables anytime soon unless they are forced to.

They're thinking about fibre, but the cost of it is very high relative to the return. Much of the blame lays with Ofcom. By forcing BT to open up their network to anyone who wants to use it, they have denied BT a guaranteed return on any investment - so BT tend to have adopted a 'why bother' policy.

Gary · Oct 08, 2007, 16:29:42

Quote from: Rik on Oct 08, 2007, 16:26:37
They're thinking about fibre, but the cost of it is very high relative to the return. Much of the blame lays with Ofcom. By forcing BT to open up their network to anyone who wants to use it, they have denied BT a guaranteed return on any investment - so BT tend to have adopted a 'why bother' policy.

Also BT have invested so much into their 21st century network roll out, which will still be behind the times, we probably won't see any change soon

gingerjedi · Oct 08, 2007, 16:42:48

Does BT's own line checker actually check anything or does it just return a theoretical result? Mine says I can have 2meg standard and 4meg and above for Max.

Reading into it, what it really says is: If your line is of a standard we would expect then fine you can have this... if its not... tough!

Inactive · Oct 08, 2007, 16:43:18

Quote from: gingerjedi on Oct 08, 2007, 16:22:33
Wow... it's about time that BT were brought into the 21st century and given a good kick up the arse! My dad live in rural Spain where he gets 13meg,

Your Dad is very, very, lucky to get that speed in rural Spain, and I bet he pays more than we do in the UK, especially as Telefonica have an effective monopoly.

In Spain, the faster the speed, the less you pay, now how daft is that? .. only about 10% of Spain can get the highest speeds.

Rik · Oct 08, 2007, 16:45:41

Quote from: gingerjedi on Oct 08, 2007, 16:42:48
Does BT's own line checker actually check anything or does it just return a theoretical result? Mine says I can have 2meg standard and 4meg and above for Max.

It's a database, which can be wildly wrong (and sometimes needs to be manually corrected before you can order BB). It does seem to adjust the prediction for Max in line with actual performance, though.

BT's current standards say 2Mbps for attenuation up to 43db, 1Mbps for attenuation up to (I think) 57db and they'll do their best to get 512k for anyone else.

gingerjedi · Oct 08, 2007, 16:52:48

Quote from: Inactive on Oct 08, 2007, 16:43:18
Your Dad is very, very, lucky to get that speed in rural Spain, and I bet he pays more than we do in the UK, especially as Telefonica have an effective monopoly.

In Spain, the faster the speed, the less you pay, now how daft is that? .. only about 10% of Spain can get the highest speeds.

He only had it put in recently, they came out and laid a cable especially and knowing my dad (penny pincher!) he didn't pay much for it and I bet he is not paying any more than the £25 a month that I am paying for this, he said he was on their 'light' package and he could have the speed doubled if he wanted!!!

I'll email him tonight and find out exactly what he paid for it, installation and monthly cost.

He also only pays 6 euro a month for a mobile phone on contract with comparable service to my £35 O2 contract so I wouldn't believe everything about comms being expensive in Spain.

Inactive · Oct 08, 2007, 17:06:49

Fair enough, but the max speed available via Telefonica is 4MB, and that is 40 Euro's a month A IVA ( VAT ) after the first 3 months.

http://www.telefonicainenglish.com/Help%20Desk/ADSL_info.htm

gingerjedi · Oct 08, 2007, 19:36:44

I guess he must have cable BB provided by a local private business, when I say rural I mean 10 miles from the coast and 20 miles from Alicante.

I just plugged my router direct inside the master socket, the attenuation was the same and when I plugged a phone into the filter the noise was there so its either my line externaly or my router thats faulty, I'm going to buy a router and see if its the same, if it is I'll just take it back.

Thanks to everyone for your input.

Rik · Oct 08, 2007, 23:35:02

Keep us posted. Most routers come with a filter or two, so it would be worth swapping those in if the problem persists.

merlin · Nov 27, 2007, 22:13:52

i noticed during this discussion, that star or daisy chain house wiring was mentioned, does this make a difference, is one better than the other

mine is a sort of combination of the two options (like two Y's joined at the bottom )
something like this >----<----to street.
with four wall sockets, one at the top leg of each Y, one of which is connected to my modem ,with nation filters at each outlet

is this good ,bad ,or indifferent

thx in advance

Rik · Nov 28, 2007, 00:48:35

Probably bad, by modern standards. Star topology was common pre-ADSL, but that really is a bad idea for noise - daisy-chaining will generally give a better result.

gingerjedi · Dec 06, 2007, 13:56:39

Just noticed my post was resurrected!

Since then I've tried a linksys which was ok but wireless and VPN was rubbish, I got another DG834GT and the problem was the same (thanks to PC world for the rentals!), I had BT in via IDNET who replaced the master socket which seemed to do the trick but after a week I noticed the problem creeping back.

Maybe the line is fit for purpose in BT's eyes but both netgear routers I tried didn't like it? Maybe they operate in some weird way that conflicts with my line conditions??

I've all but given up but as they're so cheap I'm off to look at the 2wires I keep hearing so much about!

Rik · Dec 06, 2007, 14:35:12

To judge by my experience of the 2700, and I'm still a newbie with it, you won't be disappointed. I have had both better sync speed and a more stable noise margin since installing it.

ducky22 · Dec 06, 2007, 15:47:06

Call BT 150 and tell them you can intermittantly hear other people's conversations when you're on the phone.

It is an almost impossible problem to track down and they'll probably just swap you to another pair no questions asked. It costs to much to get the RFI team involved to investigate fully.

That may make the problem worse.... but it could also increase your speeds substantially.

Lance · Dec 06, 2007, 20:16:06

I like your style, Ducky!

ducky22 · Dec 06, 2007, 22:26:39

Quote from: Lance on Dec 06, 2007, 20:16:06
I like your style, Ducky!

I was a consultant for BT for a year. I know a few tricks... That one I actually learnt by accident quite recently. I never knew standard proceedure for fixing strong intermittant cross-talk was to swap the pair!

Rik · Dec 06, 2007, 23:55:00

With my luck, I'd get the worse pair they had.

I am actually lucky, I was an early adopter, and when I had a problem, the BT engineer was very friendly, and swapped pairs to get me the best result he could. As I manage a 2500 profile while my neighbours are on 1000 or 500, he seems to have done a pretty good job.