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Noise Margin

orbrey
Plusnet Alumni (retired)
Plusnet Alumni (retired)
Posts: 10,540
Registered: ‎18-07-2007

Re: Noise Margin

Hi HaydnExport,
It had dropped to 3500 as of 13:09 so I moved our profile to match.
HaydnExport
Grafter
Posts: 567
Registered: ‎23-10-2009

Re: Noise Margin

hi , ye router got switched off by mistake this morning  Roll_eyes  Have synced now at 5696 so cross fingers i can stay on that lol
HaydnExport
Grafter
Posts: 567
Registered: ‎23-10-2009

Re: Noise Margin

Nope dropped again at 11.38am ish this morning, what looks odd is the signal noise is fine then just completely drops  Cry

HaydnExport
Grafter
Posts: 567
Registered: ‎23-10-2009

Re: Noise Margin

I take it the drop in the last post was because of friday's problems?  As have been stable enough for bt to raise my ip profile to 5000 kbps  Wink
HaydnExport
Grafter
Posts: 567
Registered: ‎23-10-2009

Re: Noise Margin

plusnet ip still at 3500k
Edit, Any chance of a nudge ?
HaydnExport
Grafter
Posts: 567
Registered: ‎23-10-2009

Re: Noise Margin

been great for 2 weeks and a sudden loss early yesterday morning and another around 10am this morning  I have routerstats captures.  If anyone could offer a solution or advice it would be most welcome.



HaydnExport
Grafter
Posts: 567
Registered: ‎23-10-2009

Re: Noise Margin

FFS its happened again !!  i synced at 5120 and a noise margin of 12 so it wouldnt happen again and it has, out of the blue again no lost connection as i was in the middle of a game !!  What does it take for you to prove you have a fault on your line???  2  weeks happily synced at 5696 then lost connections 3 times in 3 days !!!  no sharp drop in noise margin just a drop in sync , why is this happening? I pay around £27 a month for this, i have bought 2 different routers , x amount of filters etc and still the same, even had a telecoms bloke here to check my nte5 wiring !!  Can someone please look into this as my patience is wearing thin
HaydnExport
Grafter
Posts: 567
Registered: ‎23-10-2009

Re: Noise Margin

and happened two more times .........
Edit:  And it has cost me a ps3 dualshock controller  Cry
Edit again :  has lost sync a further 4 times  Roll_eyes
WWWombat
Grafter
Posts: 1,412
Thanks: 4
Registered: ‎29-01-2009

Re: Noise Margin

It looks to me like you have a decidedly intermittent problem somewhere between yourself and the exchange.
That problem is viewed by the exchange DLM as a big interference in your stability, so it is actively trying to improve the stability by increasing the noise margin.
The downside is that this limits the sync speed, and gets reflected (immediately, and for a long time after) in the profiles and your download speed
The problem is, because this "fault" is largely invisible to you and goes away again, only the after-effects are visible to you: a slow download, low profiles, and changing sync speed.
If all you do is a resync and ask for the profiles to be fixed, then unfortunately, you are only ever going to cure the symptoms, and never cure the original fault.
You have my sympathy. This kind of intermittent problem is about the hardest thing for anyone to solve, and requires patience and a methodical approach.
Even if all you want to do is hand this off to one of BT's technician's, you're going to need patience - because it will be hard for him to find the fault, hard for him to fix the fault, and hard for you to know whether the fix has had any real effect.
I see you've tried routers, filters, and had a visit to check the NTE5. That's a start (OK, quite a way round the next lap too), but it looks like there's more work that's needed...
You've also got some good graphs out of RouterStats. They show the problem happening, but even they're not good enough to show the cause.
For example, the drop at 3:44 shows this to a tee. The sync drops for no apparent reason (certainly no serious dip in the noise margin). When it re-syncs, it does so with a high SNR level, suggesting that the exchange DLM has ordered this to be increased. Consequently the speed has decreased, and this will be immediately reflected in the profile and download speeds.
But no hint of why the sync dropped.
The drop at 5:09 has less consequences on either your sync speed or your profile, but there is still no indication why.
If you want to try to gather better evidence about the line, then I suggest that you try to augment the RouterStats graphs to also collect data about the number of errors being seen on the line. These will be displayed by the router (if at all available) as CRC or HEC. You may also see ES (Errored Seconds) figures too.
You might find that graphing these details will give you a better understanding of your line at the time it fails.
If nothing else, they'll give you a "before" picture, to allow you to assess whether any attempted BT-fix has actually had any impact on the line.
With 3 routers, they might also let you asses which router handles the line best... assuming you can get matching data out of all 3.
Plusnet Customer
Using FTTC since 2011. Currently on 80/20 Unlimited Fibre Extra.
WWWombat
Grafter
Posts: 1,412
Thanks: 4
Registered: ‎29-01-2009

Re: Noise Margin

It was just pointed out to me that you need the full version of RouterStats to get the error logging, rather than just the -lite version.
Plusnet Customer
Using FTTC since 2011. Currently on 80/20 Unlimited Fibre Extra.
HaydnExport
Grafter
Posts: 567
Registered: ‎23-10-2009

Re: Noise Margin

Thanks for the great reply , i do have the full routerstats i kind of stuck with the lite version as it worked with the bt2700hgv.  I'll run the other one and get the errors .   It lost sync 5 more times last night but stayed at near enough the same rate(even went up slightly twice)
HaydnExport
Grafter
Posts: 567
Registered: ‎23-10-2009

Re: Noise Margin

and dropped connection another few times today, are there any plusnet staff reading this or should i ring someone at cs who doesnt have a clue?
spraxyt
Resting Legend
Posts: 10,063
Thanks: 674
Fixes: 75
Registered: ‎06-04-2007

Re: Noise Margin

The faults team might be a bit thin on the ground until Monday.
David
HaydnExport
Grafter
Posts: 567
Registered: ‎23-10-2009

Re: Noise Margin

Has been stable for 3 days then dropped just after midnight last night , again no drop in nm just drops connection  Sad
orbrey
Plusnet Alumni (retired)
Plusnet Alumni (retired)
Posts: 10,540
Registered: ‎18-07-2007

Re: Noise Margin

Hmm, it must have been a very short blip as it's not showing on your connection logs on our side though there's a fair number of disconnections from the afternoon of the 21st showing on there.
If you're getting a lot of these disconnections I'd definitely recommend raising us a fault at http://faults.plus.net