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Standard User IamQ
(committed) Sat 03-Apr-10 15:02:45
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Re: ADSL2+ SNR and Max rate


[re: TerryN] [link to this post]
 
In reply to a post by TerryN:
(but I still needed to get my ISP to kick BT to put me back to "Normal Stablility" and 6dB SNRM afterwards)


How where they at doing it ? I have tried lots of times on ADSL1 to get margins reset and I always got the same spin from most ISP's (including the good ones like Zen) that 'ohh no - we can't do that anymore'

It was very hit & miss though I did manage to get it done for a couple of lines (with another ISP), it involves a full BT retrain period though and you might not end up any better off at the end of it...

BTWS should be the provider of last resort IMHO there not really fit for much else when all the LLU folks can get it right and much more stable. All I will say though is it looks like BTWS are running with SRA on there ADSL2+ endpoints.
Standard User chris6273
(learned) Sat 03-Apr-10 15:54:20
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Re: ADSL2+ SNR and Max rate


[re: IamQ] [link to this post]
 
Sooo can you tweak your 21CN SNR at all without having the DLM interferring?

My Broadband Speed Test


Downstream Upstream
Connection Speed 8128 kbps 448 kbps
Line Attenuation 13.0 db 10.0 db
Standard User TerryN
(newbie) Sat 03-Apr-10 16:06:28
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Re: ADSL2+ SNR and Max rate


[re: IamQ] [link to this post]
 
In reply to a post by IamQ:
In reply to a post by TerryN:
(but I still needed to get my ISP to kick BT to put me back to "Normal Stablility" and 6dB SNRM afterwards)


How where they at doing it ? I have tried lots of times on ADSL1 to get margins reset and I always got the same spin from most ISP's (including the good ones like Zen) that 'ohh no - we can't do that anymore'


Well I'm with AAISP so this sort of thing is not a problem at all.

If your ISP won't help you with this ... you need a new ISP !

Terry


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Standard User IamQ
(committed) Sat 03-Apr-10 18:25:46
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Re: ADSL2+ SNR and Max rate


[re: TerryN] [link to this post]
 
In reply to a post by TerryN:
Well I'm with AAISP so this sort of thing is not a problem at all.


Alas as much as I respect them - they tinker just a bit too much for me.

Hat's off to them though for some of the things they have managed to do though. I'm am happy where I am for the moment, alas as I said before it comes down to BTWS's systems though.

Once they open them up as the LLU providers have things should get better, otherwise as I've said before BTWS will become the provider of last resort where there is good LLU coverage.
Standard User stephen79
(fountain of knowledge) Mon 05-Apr-10 20:20:33
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Re: ADSL2+ SNR and Max rate


[re: stephen79] [link to this post]
 
In reply to a post by stephen79:
oh damn, this morning it went even worse

Down Up
SNR (dB): 14.4 5.2
Attn(dB): 45.0 25.9
Pwr(dBm): 20.0 12.3
Max(Kbps): 6516 17563
Rate (Kbps): 3072 848


OK, so I haven't forced a resync and my line hasn't dropped now for 2 days. So, my speed is still as above. Do you think I am safe to force a resync now and see if I can improve on it or would you expect it to get worse? Basically, will the BT BRAS have reset or do I need to wait a few more days?

entanet
Standard User Apprentice
(knowledge is power) Mon 05-Apr-10 22:53:08
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Re: ADSL2+ SNR and Max rate


[re: stephen79] [link to this post]
 
I would wait.

Alastair

omadasafisho
Standard User Chrysalis
(eat-sleep-adslguide) Tue 06-Apr-10 11:53:26
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Re: ADSL2+ SNR and Max rate


[re: stephen79] [link to this post]
 
the question is.

what is the highest sync speed you have had whilst the line is stable?

I think you screwed until your isp overides the DLM, probably by getting your profile reset.

the 21CN DLM seems very oversensitive to drops, even if its you resetting the modem.
Standard User stephen79
(fountain of knowledge) Tue 06-Apr-10 14:50:55
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Re: ADSL2+ SNR and Max rate


[re: Chrysalis] [link to this post]
 
In reply to a post by Chrysalis:
the question is.

what is the highest sync speed you have had whilst the line is stable?

I think you screwed until your isp overides the DLM, probably by getting your profile reset.

the 21CN DLM seems very oversensitive to drops, even if its you resetting the modem.


I haven't really been able to test that; I am stuck on 3072/9.2 (atten/snr)

The first day of the ADSL2+ upgrade with a forced SNR of 6dB I got 5783/5.9 and this seemed stable even in the evening when my SNR dropped down to 3dB but the line resynced atl 5am he next morning.

I have been running routerstats to monitor my SNR for the last 3 days and it's been almost a constant 9.x but obviously this is a low sync speed. If it's no better by the weekend I will force a G.DMT connection.

entanet
Standard User IamQ
(committed) Thu 08-Apr-10 00:01:14
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Re: ADSL2+ SNR and Max rate


[re: stephen79] [link to this post]
 
So here is stats from one of my better lines that got migrated yesterday onto ADSL2+

NOTE The DS Attainable rate is *lower* that my sync rate and is wondering about all over the place at the moment. Down as low as 8000.

This is off a Draytek 2820 with the Alternate UK modem code on.

> adsl stat
--------------------------- ATU-R Info (hw: annex A, f/w: annex A) -----------
Running Mode : ADSL2+(G.992.5) State : SHOWTIME
DS Actual Rate : 9081000 bps US Actual Rate : 963000 bps
DS Attainable Rate : 8076000 bps US Attainable Rate : 964000 bps
DS Path Mode : Fast US Path Mode : Fast
DS Interleave Depth : 1 US Interleave Depth : 1
NE Current Attenuation : 35 dB Cur SNR Margin : 7 dB
DS actual PSD : 20. 7 dB US actual PSD : 12. 3 dB
ADSL Firmware Version : 232201_A
-------------------------------- ATU-C Info ---------------------------------
Far Current Attenuation : 17 dB Far SNR Margin : 6 dB
CO ITU Version[0] : 00004946 CO ITU Version[1] : 0000544e
DSLAM CHIPSET VENDOR : < IFTN >

Edited by IamQ (Thu 08-Apr-10 00:41:56)

Standard User stephen79
(fountain of knowledge) Sun 11-Apr-10 18:20:58
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Re: ADSL2+ SNR and Max rate


[re: IamQ] [link to this post]
 
Mine seemed to clear after a week but it quickly went back to a capped speed again.

I have just force ADSL1 G.DMT and the stats are much better, I just need to wait for the connection rate cap to be removed crazy

Noise Margin: 14.5 dB
Connection Rate: 3072 Kbps
Line Attenuation: 42.0 dB
Power: 19.7 dBm
Max Rate: 6784 Kbps

entanet
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