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Standard User scorpiouk
(newbie) Tue 29-Aug-17 14:23:50
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SNR vs Noise Margin


[link to this post]
 
MY Cr^^*y SSE router, a "MediaAccess TG589vac" does not seem to display the SNR..

I can see the following:

Line Rate (D)20 Mbps (U)55.4 Mbps
Output Power (D)4.7 dBm (U)4.7 dBm
Line Attenuation (D) 0 dB (U) 0 dB
Noise Margin (D) 6.9 dB (U)6.3 dB

When we moved into the house, a new build 300m from the Cab we were getting 80/20mbps.
Following a number of power cuts by the buildders we well to less than half this on the Download.. Eventually, I managed to get it back up to aoru nd 68 -70 and was happy at that..

Last week a storm took out the power again, my 70mb fell to 55mb..

I waited until a few days had passed to show the line was stable, switches off PPP, and then shut down the router.. left it 30mins and brought it back up..

The power output fell from 5.2 to 4.7, and the Noise Margin didnt see, to change.. I know rebooting the router should be done when the SNR is at its best, but with only Noise Margin is that when its high or low?

Assuming Noise Margin being high is best?

What about power output? Lower the better as there is low noise on the line?

Thanks for the advice.
Standard User j0hn83
(committed) Tue 29-Aug-17 14:29:40
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Re: SNR vs Noise Margin


[re: scorpiouk] [link to this post]
 
Noise Margin (D) 6.9 dB (U)6.3 dB

^^ SNR Margin

Edited by j0hn83 (Tue 29-Aug-17 14:30:38)

Standard User BatBoy
(sensei) Tue 29-Aug-17 14:35:34
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Re: SNR vs Noise Margin


[re: scorpiouk] [link to this post]
 
I don't think you'll ever see the SNR, just the SNRM (noise margin). I suppose it's best to reboot when the snrm is highest but as your connection is controlled by DLM, it's probably best to leave it to DLM to manage your connection. Except on the odd occasion that you've synced low for some reason and the snrm will be unusually high, as it's currently around the target of 6 probably best to leave it.


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Standard User j0hn83
(committed) Tue 29-Aug-17 15:02:40
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Re: SNR vs Noise Margin


[re: scorpiouk] [link to this post]
 
The line has likely been banded (sync is capped) due to too many disconnections. The SNRM being stuck above 6 also suggests this.

Stop resyncing. All you will do is make it take even longer to return speeds to normal. DLM acts in its own time, no manual resync will fix it, no matter the time of day.
Standard User nemeth782
(committed) Tue 29-Aug-17 15:16:38
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Re: SNR vs Noise Margin


[re: scorpiouk] [link to this post]
 
You're also in a new build, so it's reasonable to assume crosstalk is increasing as more people move in and take up services.
Standard User scorpiouk
(newbie) Tue 29-Aug-17 15:27:49
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Re: SNR vs Noise Margin


[re: nemeth782] [link to this post]
 
Thanks for all the replies..

We did have Openreach out and they did say the line wasn't capped at that time. But that could have changed.

I monitored the connection daily for 8 months. It never seems to be managed and unless there is some power issue the speed is always the same.

We did see the speed drop as people move in, but the biggest difference is the power cuts.

So I want the SNRM to be low?
Is there any thing i can do to help?

When my deal with my ISP ends and I change, does the new connection with the new ISP all start over? Or is it going to remember the disconnections from when this was a building site?

thanks again
Standard User Zarjaz
(eat-sleep-adslguide) Tue 29-Aug-17 15:40:11
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Re: SNR vs Noise Margin


[re: scorpiouk] [link to this post]
 
What you want your SNR to be, is exactly what it's target is , usually 6db. Unless Your purchased speed is less than the line can provide, in which case your SNR may appear as higher than the target.

A change of provider should see the connection back to 'out of the box' settings.

Standard User scorpiouk
(newbie) Tue 29-Aug-17 15:42:45
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Re: SNR vs Noise Margin


[re: Zarjaz] [link to this post]
 
Thanks...

so closer to 6 the better.

Think I might need to switch at the end of this.
Standard User Zarjaz
(eat-sleep-adslguide) Tue 29-Aug-17 15:44:27
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Re: SNR vs Noise Margin


[re: scorpiouk] [link to this post]
 
Who are you currently with ?

Looks to me as though you just need a DLM reset.

Standard User scorpiouk
(newbie) Tue 29-Aug-17 16:09:44
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Re: SNR vs Noise Margin


[re: Zarjaz] [link to this post]
 
SSE broadband... all in (LR, Calls, BB, etc) £21..

Been ok..
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