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[burakkucat]

For completeness and the entire 'back story', I provide the links to Matt's four threads in the ThinkBroadband fora --

Slow internet/low IP profile/high noise margin on Tesco
Slow internet/noise margin questions on Tesco Broadband
Reduced sync speeds on Tesco Broadband
Will switching ISP get me a better sync?

I did read each and every post, more or less in 'real time', as they were made 'over there'. As to be expected, things did start to get a little bit confusing, what with certain people just wanting to 'have their say'. 

[kitz]

>>>  Another difference between your problem and mine is that with mine, after the fault my target snr was put at 15db,

Your fault had been present for a while, therefore during the fault period the DLM will have had chance to go through all the profiles - ending up with the highest - in an attempt to stabilise your line.

My problem occured after just one brief power outage, therefore it will recover quicker - my line wasnt unstable enough to go any further than interleaving and was still on the default 6dB SNRM profile. 

The only point I was trying to make in this thread.. is that for some reason something seems to trigger a cut back of power to fit the SRNM ie leaving no surplus SNR margin like you would normally see.   I'd only dug out that thread so that you could see my stats also showing SNRm at the same rate set on the DLM, with power cut restricting the speed.

Bear in mind the thread I pointed to you was just one of many instances over a 3 year period when my line would do silly things that the DLM is just not supposed to do.   Its why I got so fed up of the BTw maxdsl profiling system and jumped off it as soon as I possibly could.

Switching to adsl2+ should hopefully start a new retrain on your line.   
Why this didnt happen after your line fault was repaired is another matter, and one that I would be pushing my ISP for now, if it wasnt for the fact that you are moving over to a new product in a few days.

>>>> I provide the links to Matt's four threads in the ThinkBroadband fora

I hadnt realised that it had been topic of conversation over there too..  I chipped in purely because I noticed the power cut back which will without doubt be what is restricting your speed. 
Unfort I just dont have time atm to read through those threads, but there are some very knowledgeable people over there who are also capable of providing correct information, it may be just that no-one noticed the power cut back.   I only knew to look for it because Ive seen it happen before on very short lines.

[matthewcl375]

Kitz that is true, I am surprised that I and others didn't notice the output power stats earlier on, I think we were so busy looking at the SN Margin and Sync Speed to notice 

Also, not to start a forum war here  but a lot of people on TBB did just want to have their say and many times I didn't get concise answers, whereas here you have all been very helpful and straight to the point, I didn't have to keep asking for clarification or getting 3+ conflicting opinions every time I asked a question which only confused me more 

[kitz]

TBH the thing that really should have been done is a full retrain of your line after the fault was fixed rather than you having to go through the long slow process of waiting for the DLM to slowly go back down through each profile.  From the information provided its obvious that this hasn't been done.

Most of the 'decent' ISPs should have been able to have arranged this for you after a line fault fix. 
I just had a very quick look at one of the TBB threads, and although I didn't get to the end - it's getting late and bedtime for me - I was surprised at how long this had been going on.

I'm not quite sure if it's worth perusing a retrain now since you are soon to go adsl2+ and by the time you get through to someone to action your request it may be too late anyhow.   I'm not quite sure are you staying with tesco or going elsewhere?

[burakkucat]

I'm not quite sure are you staying with tesco or going elsewhere?

I can quickly answer that before I, too, go and find my warm and sleepy spot! 

On the 25th of this month we are having BT Broadband activated . . .

From the very first line of the post by Matt, at the start of his fourth thread over at the TBB fora. 

[matthewcl375]

That's right! It's with BT and I have just phoned them now, order is all good and the MAC code was according to the CS staff 'not needed now' which I take to mean they have entered it/stored it on their system and it is valid  However she also thought I was on cable, presumably because my ISP is Cable and Wireless 

I have little doubt that the migration will fix a lot of the slow line problems we have been experiencing over the last month or so 

[kitz]

Good luck and I hope it all goes well for you

[matthewcl375]

Thanks Kitz, I was wondering if you would know what kind of speeds I should see on ADSL2+ in the unlikely event of my downstream output power not rising and staying near 13.8?

[kitz]

>>>  in the unlikely event of my downstream output power not rising and staying near 13.8?

no idea TBH, but obviously no where near the full 24Mbps you should be near getting.

Mine now runs at about 18/19dBm on a 3dB SNRM

[matthewcl375]

I have a niggling feeling it will improve  but we shall wait and see, as I say it's getting activated monday, will report back then 

[matthewcl375]

OK, BT Broadband was activated earlier this afternoon, my stats are below, output power has increased but not syncing at full speed YET:

Connection Information

Line state:   Connected
Connection time:   0 days, 01:22:12
Downstream:   15.7 Mbps
Upstream:   888.9 Kbps
 
ADSL Settings

VPI/VCI:   0/38
Type:   PPPoA
Modulation:   G.992.5 Annex A
Latency type:   Interleaved
Noise margin (Down/Up):   9.3 dB / 12.0 dB
Line attenuation (Down/Up):   6.2 dB / 3.3 dB
Output power (Down/Up):   20.0 dBm / 10.6 dBm
FEC Events (Down/Up):   14 / 0
CRC Events (Down/Up):   0 / 32
Loss of Framing (Local/Remote):   0 / 0
Loss of Signal (Local/Remote):   0 / 0
Loss of Power (Local/Remote):   0 / 0
HEC Events (Down/Up):   0 / 11
Error Seconds (Local/Remote):   4 / 0

[kitz]

9.3 dB SNRM is taking away some of your sync speed (default is 6 dB)...  and it also appears that the line is interleaved, which will also be costing you some sync speed. 


Edited to add.
May be worth monitoring the line with Routerstats to check that the SNRM isnt fluctuating.

[Black Sheep]

Would the margin not be expected to be higher than that, given the very, very near proximity to the Exchange ?? I usually see them up at 18dB when they're so close ?? 

[matthewcl375]

I have no idea why the SNR Margin isn't higher, this is a problem I've seen before, Kitz suggested that my output power was too low to supply that extra SNRM, but now it's gone up to 20dbM I can't see what's causing it 

[kitz]

Would the margin not be expected to be higher than that, given the very, very near proximity to the Exchange ?? I usually see them up at 18dB when they're so close ?? 

The weird thing though BS,  the line isn't syncing (yet) to full potential.  It's only syncing at 15.7 Mbps, yet it's running at full 20dBm power.   I'd expect the power to run at about 18dbm. 

My attenuation is slightly higher, and I can sync higher than that.  Iirc when I first went on adsl2 + my sync was around 18 / 19 mbps when interleaved on default 6db SNRM.  Moving to FAST increased my sync quite a lot.. to 24 mbps with 3db SNRm.  Harder to compare now cause I'm on annex m.


The line also seems to be displaying some errored seconds. But not many...  But worth keeping an eye on.