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Standard User zarkrax
(regular) Fri 12-Oct-12 18:58:59
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Is this DLM


[link to this post]
 
Normally I get sync rates between 6.5mb to 7.1mb on my broadband.

Today the telegraph pole was changed outside my house, and when it was reconnected my sync speed was set at 6.5mb. Now I have been rebooting my router not ten times in an hour more like 5-6 times over 8hours , and every time the sync speed is lower, its now just over 6mb.

Is this DLM, and how long do I need to leave it to see if my line speed should go back up again? I thought I would need to reboot the router to retrain it, but I don't want to keep rebooting if the sync speed keeps getting lower.

I have BT Broadband, and using a Netgear DGN2200 router if that makes any difference.

TIA
Administrator MrSaffron
(staff) Fri 12-Oct-12 19:15:06
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Re: Is this DLM


[re: zarkrax] [link to this post]
 
If the router was connected to the line while the telegraph pole work was done then DLM may have seen lots of errors.

To tell if it is DLM then the other figures like attenuation and noise margin need looking at also

Andrew Ferguson, andrew@thinkbroadband.com
www.thinkbroadband.com - formerly known as ADSLguide.org.uk
The author of the above post is a thinkbroadband staff member. It may not constitute an official statement on behalf of thinkbroadband.
Standard User zarkrax
(regular) Fri 12-Oct-12 19:19:45
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Re: Is this DLM


[re: MrSaffron] [link to this post]
 
Ok thanks, I just did another reboot and the sync has now dropped even further to 5.7.

So I guess I better not reboot anymore!

I guess is what I am trying to ask is, when will the sync speeds start to go back up? Will I need to reboot my router to see the improvement?

Thanks

Edited by zarkrax (Fri 12-Oct-12 19:20:03)


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Standard User flippery
(member) Fri 12-Oct-12 19:40:36
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Re: Is this DLM


[re: MrSaffron] [link to this post]
 
I would leave it 24 hours. Then reboot in the morning. Always stated here that this is best time to get fastest sync.
As per other poster. Have your SNR and Attenuation changed with work carried out.
Posting these figures will give others opportunity to advise speed
Administrator MrSaffron
(staff) Fri 12-Oct-12 19:53:41
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Re: Is this DLM


[re: zarkrax] [link to this post]
 
Depends on why the sync is so low, the pole change may have affected the characteristics of the line for the worse

Andrew Ferguson, andrew@thinkbroadband.com
www.thinkbroadband.com - formerly known as ADSLguide.org.uk
The author of the above post is a thinkbroadband staff member. It may not constitute an official statement on behalf of thinkbroadband.
Standard User zarkrax
(regular) Fri 12-Oct-12 20:22:22
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Re: Is this DLM


[re: MrSaffron] [link to this post]
 
Ok here are my stats:

DSL Link Downstream Upstream
Speed 5711 kbps 1112 kbps
Attenuation 48.5 db 22.3 db
Noise Margin 6.6 db 6.1 db

As I don't keep historical records I can't tell you what they were before, sorry frown
I hope changing the pole hasn't changed my line for the worse frown

AFAICR The times were roughly these.

10.30 6.5 sync after line was reconnected.
16.30 6.3 sync after reboot
17.30 6.1 sync after reboot
18.30 6.0 sync after reboot
19.30 5.7 sync after reboot

Are you saying that me rebooting the router is making no difference to the sync speed?

Thanks again
Administrator MrSaffron
(staff) Fri 12-Oct-12 21:42:47
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Re: Is this DLM


[re: zarkrax] [link to this post]
 
If it was DLM I would expect the noise margin to be higher, rather than a more standard 6dB value.

So unless you had the ultra stable 3dB setting before then not much to do.

Might be worth trying forcing ADSL2 mode in a day or two, rather than letting it auto negotiate between ADSL2+/ADSL2 and ADSL mode

Andrew Ferguson, andrew@thinkbroadband.com
www.thinkbroadband.com - formerly known as ADSLguide.org.uk
The author of the above post is a thinkbroadband staff member. It may not constitute an official statement on behalf of thinkbroadband.
Standard User XRaySpeX
(eat-sleep-adslguide) Fri 12-Oct-12 22:18:29
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Re: Is this DLM


[re: zarkrax] [link to this post]
 
You are getting about what you should get now for your attenuation @ 6 dB NM.

So either:
  • You were on the lower 3dB NM before. In which case you can only wait to see if it changes, or
  • The work on the pole increased your attenuation. In which it will never come back.
I doubt that your rebooting changed anything.

1999: Freeserve 48K Dial-Up => 2005: Wanadoo 1 Meg BB => 2007: Orange 2 Meg BB => 2008: Orange 8 Meg LLU => 2010: Orange 16 Meg LLU => 2011: Orange 19 Meg WBC
Standard User zarkrax
(regular) Fri 12-Oct-12 22:22:20
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Re: Is this DLM


[re: MrSaffron] [link to this post]
 
Ok, after a couple of reboots I am now down to 5.4, and no change in the line stats frown So I better stop rebooting or my BB will be really slow.

Does DLM actually control sync speed? Or just the ip profile? I thought the profile just restricted the throughput not the sync speed.

If whatever is controlling the sync speed, increases the sync speed will I need to do a reboot to see it, or will the retrain just happen?

Thanks again for all your help so far.
Administrator MrSaffron
(staff) Fri 12-Oct-12 22:34:57
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Re: Is this DLM


[re: zarkrax] [link to this post]
 
DLM mainly targets the target noise margin, but can limit the sync speed to a min and max range, but is relatively rare

Rebooting when the sun has set and people are starting to turn heating on is usually a bad time to reboot

Andrew Ferguson, andrew@thinkbroadband.com
www.thinkbroadband.com - formerly known as ADSLguide.org.uk
The author of the above post is a thinkbroadband staff member. It may not constitute an official statement on behalf of thinkbroadband.
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