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SNR too too high

davidfriedlande
Grafter
Posts: 80
Registered: 19-02-2014

SNR too too high

Can someone tell me why all of a sudden my snr is set at a stupidly high rate?
I was quite happy on 6 (i would prefer 3) which gave me a stable connection rate, now i am getting a very low sync rate and streaming etc is not great.

Thanks
15 REPLIES
Acassim
Grafter
Posts: 1,075
Thanks: 1
Registered: 11-06-2007

Re: SNR too too high

Hi david,
Sorry to hear you're having issues with the speed of the service.
Would it be possible for you to reconnect your equipment into the BT test socket and retest the speed/SNR margins over a few hours?
Just looking at the details of your line and RADIUS logs I can't see anything overly apparent that could be causing this assuming that the disconnections below are you power cycling the router once you saw the speed drop.
<img src="http://community.plus.net/visualradius/generated/image14029123586775.png"/>
Superuser
Superuser
Posts: 11,539
Thanks: 2,957
Fixes: 22
Registered: 22-08-2007

Re: SNR too too high

Can you please post your full router stats?
Is your phone line noisy?
davidfriedlande
Grafter
Posts: 80
Registered: 19-02-2014

Re: SNR too too high

Parameters
DSP Firmware Version A2pB025f.d22k
DMT Status No Defect
Operational Mode ADSL2+
Upstream 1067
Downstream 7367
SNR Margin(Upstream) 5.9
SNR Margin(Downstream) 9.6
Line Attenuation(Upstream) 24.7
Line Attenuation(Downstream) 42.5
my disconnects are me trying to get a better sync and tweaking my routers snr page, i am already in the test socket so that is not an issue. i am not at home to see if there is any noise but i have never had a problem before
davidfriedlande
Grafter
Posts: 80
Registered: 19-02-2014

Re: SNR too too high

What is my target SNR set to please?
Acassim
Grafter
Posts: 1,075
Thanks: 1
Registered: 11-06-2007

Re: SNR too too high

Hi David,
Your target SNR is currently set at 12db although you're currently in sync at 6db so while your target is high your actually seeing a better result.

Thanks,
Adam C

Superuser
Superuser
Posts: 11,539
Thanks: 2,957
Fixes: 22
Registered: 22-08-2007

Re: SNR too too high

Adam,
Can you clarify this please?  Where do you get 6dB from - it's not in data  provided by the user above?
With the reported attenuation, the synch at 6dB should be around 8Mbps.  The user reported synch rate at 9dB would be about right.  If the target SNRM is 12dB then either line noise has driven the current SNRM down to 6dB or the user has "fixed" his router to ignore the target.
If the router is stable at 6dB is there a need for a SNRM reset?  If after that it drifts up again, then there is a fault requiring investigation.
Kevin
Acassim
Grafter
Posts: 1,075
Thanks: 1
Registered: 11-06-2007

Re: SNR too too high

Hi Kevin,
Both the target and current SNR values were taken from the full set of faults tests around 5 minutes before I posted so these are the values in play at the time of the checks.
I would then guess that David has either had a re-sync since posting his previous router logs or has indeed manually fixed his SNR within his equipment.

Thanks,
Adam C
davidfriedlande
Grafter
Posts: 80
Registered: 19-02-2014

Re: SNR too too high

i have indeed used my routers snr tweak to get it down to 6, but ideally i want my plusnet set snr to be at 6 (prefer 3) and not 12 as it is not necessary to be that high.
can someone look into this for me?
Acassim
Grafter
Posts: 1,075
Thanks: 1
Registered: 11-06-2007

Re: SNR too too high

Hi David,
I've now raised a request for the SNR to be reset to 6db, this should be complete within the next 4 hours.

Thanks,
Adam C
Superuser
Superuser
Posts: 11,539
Thanks: 2,957
Fixes: 22
Registered: 22-08-2007

Re: SNR too too high

Adam,
For clarity, I take it this is a TARGET SNRM reset to 6dB which will put the DLM into a 10 day training period which will shift the line characteristics in line with the encountered stability.  If the line is good, the SNRM might fall to 3dB but if it is not, it will rise again above 6dB, in which case an underlying issues needs to be investigated.  In the meantime am I correct that artificially fudging the router to locally manage the SNRM is not helpful?
Kevin
Acassim
Grafter
Posts: 1,075
Thanks: 1
Registered: 11-06-2007

Re: SNR too too high

Hi Kevin,
You're correct in what you're saying as changing this locally and managing it in this way could mask issues.  The SNR reset should complete any time now and if we keep the router plugged into the test socket, it will allow the DLM to manage the line as it sees fit.
If there are any adverse effects then naturally we would need to look into this.

Thanks,
Adam C
davidfriedlande
Grafter
Posts: 80
Registered: 19-02-2014

Re: SNR too too high

ok, removed my router snr tweak and thanks to Adam my actual snr is at 6 which im happy with, my next thing is my plusnet speed profile is still stuck low, can someone adjust this, i understand that it is supposed to happen automatically but it seems to me to only decrease automatically and never increase?
Acassim
Grafter
Posts: 1,075
Thanks: 1
Registered: 11-06-2007

Re: SNR too too high

Hi David,
I've brought the speed up in line with the current sync rate shown in in a wholesale line check so this has come up from around 6.5 to 7.8mbps. This would have happened automatically however changes up/down can sometimes take a few days to appear.

Thanks,
Adam C
davidfriedlande
Grafter
Posts: 80
Registered: 19-02-2014

Re: SNR too too high

once again plusnet profile not updating!
it is very quick to reduce but after 2 days still not going up to what it should be...
it shoes 7.8 but bt profile is 8.35