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SNR reset

mike0381
Grafter
Posts: 88
Registered: 14-02-2012

SNR reset

Hi, as you may know, I live in a house with slightly dodgy electrics.  The last couple of days I've had a new woodburning stove installed, and the installer was using a heavy duty drill which kept throwing the RCD out.  I've not yet saved up to have the electrics redone but the work is finished now and there should be no further problems.
Due to all the disconnections my SNR margin and sync has gotten worse.

Could you reset my SNR to default please?

Thanks.

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

Re: SNR reset

Hi there,
Both our side and BTs are set to 1500 which looks about right for your current line rate? I realise there have been times when your connection was over 2Mb but suspect that that will happen again shortly and the profile adjust itself.
What sort of speeds are you seeing currently?
Community Veteran
Posts: 26,695
Thanks: 918
Fixes: 10
Registered: 10-04-2007

Re: SNR reset

What's the noise margin at present?
If the wiring is dodgy a UPS would eliminate those issues.
jelv (a.k.a Spoon Whittler)
   Why I have left Plusnet (warning: long post!)   
Broadband: Andrews & Arnold Home::1 (FTTC 80/20)
Line rental: Pulse 8 Home Line Rental (£13/month)
Mobile: iD mobile (£4/month)
mike0381
Grafter
Posts: 88
Registered: 14-02-2012

Re: SNR reset

The noise margin is 11.5 at the moment.  I notice that this has been ranging between 8.5 and 12.
The connection has just dropped out 2 hours ago and it has resynced at 1,184 which won't even give me 1mb!  I don't know what's happening with my line, it seems to be going crazy to be honest.
Community Veteran
Posts: 26,695
Thanks: 918
Fixes: 10
Registered: 10-04-2007

Re: SNR reset

Because of the drops the target noise margin will have been raised by the exchange in an attempt to stabilise the line - that means lower sync speed.
Until you can determine what is causing the drops and stop it happening you are not going to get anywhere with the speeds.
Forget about the speeds for now and just concentrate on sorting out the drops.
You've commented on the electricity supply - do you get brown-outs where the lights dim momentarily?
jelv (a.k.a Spoon Whittler)
   Why I have left Plusnet (warning: long post!)   
Broadband: Andrews & Arnold Home::1 (FTTC 80/20)
Line rental: Pulse 8 Home Line Rental (£13/month)
Mobile: iD mobile (£4/month)
mike0381
Grafter
Posts: 88
Registered: 14-02-2012

Re: SNR reset

Hi Jelv, thanks for your help.  No that's the strange thing  -   I get no brown outs at all.  I wish I did, then the solution would be simple!  However, I will purchase a UPS for those times when the RCD trips.
It's just been REALLY bad the last couple of weeks where the noise margin is going all over the place.  I might have got the odd disconnection but it was fairly infrequent and not enough to lower my profile, and the noise margin didn't seem to be so hyper so I always kept a reasonable sync speed upon reconnection. Undecided
For example now the noise margin is 9.5db (not too bad), but when I woke up and noticed it had disconnected, it was 12db.
Note:  It has now gone from 9.5db to 11.5db.
mike0381
Grafter
Posts: 88
Registered: 14-02-2012

Re: SNR reset

Can I just ask if it's normal for the signal margin to go from 8db to 12db and back within minutes?  I don't remember that happening before, I mean, I'd get a change of 1 db or something but never such a large change.
Community Veteran
Posts: 26,695
Thanks: 918
Fixes: 10
Registered: 10-04-2007

Re: SNR reset

No - it's not.
Are you running RouterStats? If you can identify a pattern to the changes you might start to get somewhere. Watch out for anything electrical being switched on and off (including PCs) when it happens.
You could try this: get a portable AM radio and tune it to 612Khz and wander around your house with it when the noise margin drops. It will act as a detector for anything that is emitting a lot of RF noise.
jelv (a.k.a Spoon Whittler)
   Why I have left Plusnet (warning: long post!)   
Broadband: Andrews & Arnold Home::1 (FTTC 80/20)
Line rental: Pulse 8 Home Line Rental (£13/month)
Mobile: iD mobile (£4/month)
mike0381
Grafter
Posts: 88
Registered: 14-02-2012

Re: SNR reset

Thanks, that's a good idea, it's something to try!  I'll get on to that right away.  I did have routerstats but removed it for some reason, I'll download it again.  Wink
Community Veteran
Posts: 19,101
Thanks: 443
Fixes: 21
Registered: 31-08-2007

Re: SNR reset

In view of your comment about the electrics, it would be worth checking that you don't have any power connection problems to where you have the modem/router plugged in, or the mains cable to it as well.
mike0381
Grafter
Posts: 88
Registered: 14-02-2012

Re: SNR reset

Hi Anotherone, I've tried 3 different routers, and I don't think there are any power problems as my cordless landline phone is plugged in at the same point and that never has a problem.  Unless routers are particularly sensitive?
It seems with the signal margin going all over the place (at the moment between 7.5db and 11db) it's almost like it doesn't even have a target any more, I have no idea what it is now!  Grin
Community Veteran
Posts: 26,695
Thanks: 918
Fixes: 10
Registered: 10-04-2007

Re: SNR reset

The target only comes in to play at the instant you do a resync - if you look at the noise margin immediately after a resync, that is your target. From then on it can go anywhere (unless it drops to low when you'll have another resync).
Have you looked to see if using the phone triggers a change in the noise margin?
jelv (a.k.a Spoon Whittler)
   Why I have left Plusnet (warning: long post!)   
Broadband: Andrews & Arnold Home::1 (FTTC 80/20)
Line rental: Pulse 8 Home Line Rental (£13/month)
Mobile: iD mobile (£4/month)
Community Veteran
Posts: 19,101
Thanks: 443
Fixes: 21
Registered: 31-08-2007

Re: SNR reset

It's likely that you've got a bad connection, can you hear crackling noises on the line when you use the phone? If so try plugging a known good corded phone directly into the test socket and confirm if any noise is still present.
mike0381
Grafter
Posts: 88
Registered: 14-02-2012

Re: SNR reset

OK, so I know my target SNR is 9db.  I thought I was doing well as the connection has been really good over the last 3 / 4 days, and been very stable with no drops, but a few hours ago the signal margin suddenly went from 9db to 16db and resynced at a lower speed.  I wish I knew what caused that sudden change!
I will get routerstats up and running to see if it helps identify a problem.
There are no crackling noises on the line at all, not that I can hear, so it doesn't seem noise is an issue...