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TiRich
Contributor
417 Views
Message 61 of 75

Re: Slow Internet - mods please assist.


@umpire wrote:
The connection speed will only change after a disconnection and reconnection.

Assuming the charts are showing correct information then the short changes to 12dB do to me indicate a temporary reduction in noise. It is just for a very short time though. If that reduction could be achieved constantly then the current connection noise margin would stay at 12dB, then after a reconnection it would go back to the default 6dB but with a faster connection speed.

One other point. Do we know what the noise margin was back when you had a faster connection speed? The DLM may have used 3dB to achieve the faster speed. You are currently telling the modem to use 6dB regardless of what the DLM thinks. My ADSL2+ line for example uses 3dB with a HomeHub4 as it is stable enough.

Try the noise margin on auto again and see what it selects?

OK. The line has been stable for 3+ days now so i will put the SNR back into auto and reboot the router.

 

No idea what the SNR was before sorry!

 

Mains chokes now fitted on Central Heating pump, Fridge and Freezer and the Router Power supply.

 

I did check the wiring outside the house (yes i know not to touch etc) and they used the gel filled scottch lock type connectors. Hate these things - might it be worth soldering the connections????

 

reboot time.......................

 

Time for a reboot.................

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imjolly
Distinguished Sage
Distinguished Sage
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Message 62 of 75

Re: Slow Internet - mods please assist.

Engineer would use gel connectors



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TiRich
Contributor
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Message 63 of 75

Re: Slow Internet - mods please assist.

Reboot done in auto SNR and IP Profile remianed at 2.54Mbps at about 6.9dB SNR MaSmiley Frustratedrgin 

 

So nothing changed with the reboot which suggests it's as good as it can be i guess?

 

1. Best Effort Test: -provides background information.

 Download  Speed
 2.53 Mbps
  
0 Mbps4 Mbps
Max Achievable Speed

 

 Download speedachieved during the test was - 2.53 Mbps
 For your connection, the acceptable range of speeds is 1.2 Mbps-4 Mbps.
 IP Profile for your line is - 2.54 Mbps


2. Upstream Test: -provides background information.

 Upload Speed
 0.41 Mbps
  
0 Mbps0.83 Mbps
Max Achievable Speed

 

Upload speed achieved during the test was - 0.41Mbps
 Additional Information:
 Upstream Rate IP profile on your line is - 0.83 Mbps

 

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imjolly
Distinguished Sage
Distinguished Sage
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Message 64 of 75

Re: Slow Internet - mods please assist.

When I had adsl I found best time to reset was about lunchtime when your noise margin was at it's highest give best scope for faster speed



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TiRich
Contributor
408 Views
Message 65 of 75

Re: Slow Internet - mods please assist.


@imjolly wrote:

When I had adsl I found best time to reset was about lunchtime when your noise margin was at it's highest give best scope for faster speed


OK thanks, worth a try tomorrow and maybe try ADSL2 again..................

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umpire
Distinguished Guru
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Message 66 of 75

Re: Slow Internet - mods please assist.

I don't know the details of how the Billion functions. If you replaced it with the HH4 again it would show the sync time noise margin (which indicates the target the DLM has chosen) in the log file. The stats will also show the G.992.x modulation mode that it's using.

If the DLM has chosen a target margin of 6dB then one other thing you could possibly try is overriding it with 5 or 4 or 3dB using the Billion. Just be aware though that even if that results in a faster connection that stays up it might still cause increased error counts which could defeat the point of the faster speed. The DLM might also then try and react to any increased error counts by altering the interleaving settings? In general if the DLM has chosen a certain target noise margin then it's for sensible reasons so overriding might not always be such a good idea. It can work ok for some lines though.

One difficulty is if you don't have any saved stats from before when running at 3.2+Mbps to compare against.

Was the initial big drop in connection speed a sudden thing or did it gradually reduce over time? That might be another clue as to the cause.
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umpire
Distinguished Guru
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Message 67 of 75

Re: Slow Internet - mods please assist.

A question for any real experts out there.

Is it possible that as more customers on the same multi-core cable to the cabinet have moved over to Infinity VDSL2 and the wider range of frequencies being used then the system has reduced the power level in use for ADSL customers to avoid crosstalk? Would that show up as increased attenuation though?
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TiRich
Contributor
387 Views
Message 68 of 75

Re: Slow Internet - mods please assist.


@umpire wrote:
I don't know the details of how the Billion functions. If you replaced it with the HH4 again it would show the sync time noise margin (which indicates the target the DLM has chosen) in the log file. The stats will also show the G.992.x modulation mode that it's using.

If the DLM has chosen a target margin of 6dB then one other thing you could possibly try is overriding it with 5 or 4 or 3dB using the Billion. Just be aware though that even if that results in a faster connection that stays up it might still cause increased error counts which could defeat the point of the faster speed. The DLM might also then try and react to any increased error counts by altering the interleaving settings? In general if the DLM has chosen a certain target noise margin then it's for sensible reasons so overriding might not always be such a good idea. It can work ok for some lines though.

One difficulty is if you don't have any saved stats from before when running at 3.2+Mbps to compare against.

Was the initial big drop in connection speed a sudden thing or did it gradually reduce over time? That might be another clue as to the cause.

Right

 

Rebooting in auto SNR did nothing so i set the SNR noise margin to 4dB and rebooted again. Over night lots of errors (50,000 ES in 12 hours) and after 12 hours i could see that the DLM had increased the SNR to 5dB from the 4dB i had set and now the errors are much lower (2,000 ES in 12 hours Approx)

 

So it looks like 5dB (or more) noise margin is going to be the best i can get.

 

The speed has deteriorated slowly over time looking in general but is verry up and down. 

 

The line IP Profile is now 2.71Mbps and speed tests show i am getting close to that. Thats as good as it has been for a long time so i think I will now leave things as they are.

 

Thanks for all the help!

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umpire
Distinguished Guru
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Message 69 of 75

Re: Slow Internet - mods please assist.

Just one point. I don't think the DLM will have increased the noise margin from 4 to 5 during a connection duration. I think the DLM just sets a target that is only used at initial connection sync time (which you had told the modem to ignore anyway).

After sync the noise margin can change at any time though just due to changes in background noise. More noise eats up some of the margin. Less noise increases the margin. Nornally there's more noise during evenings and night.

If you think about it if the background noise is at a certain level at a certain point in time and the system wants to alter the current noise margin all it can do is force a reconnection with an associated change of connection speed based on a noise margin target. That would reset the margin level to approx the target then it starts on the nornal noise roller coaster ride from there.

Happy to be corrected if wrong.
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umpire
Distinguished Guru
367 Views
Message 70 of 75

Re: Slow Internet - mods please assist.


@umpire wrote:

If you think about it if the background noise is at a certain level at a certain point in time and the system wants to alter the current noise margin all it can do is force a reconnection with an associated change of connection speed based on a noise margin target. That would reset the margin level to approx the target then it starts on the nornal noise roller coaster ride from there.

 

It could I suppose alter the signal power level which could increase the line SNR at that point in time which would make the margin between that and the required fixed SNR (for the fixed speed) bigger.

 

From what I've read though the system isn't desperately trying to maintain a set noise margin 24/7. It just sets it to an initial sensible level at sync time. That's when the current DLM target (or the current modem override target) is used.

 

Happy to be educated if others know better though. 

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