Speeds after removal of Cap

[#1]

For the last three weeks I have seen a change in performance on Monday morning, it would seem that BT run some sort of re-balance between midnight Sunday and 03:00 hrs on Mondays.
My line has been stable at 8600kps/1080kps all week - this morning, with no recorded re-sync, stats are:-

ADSL Link  Downstream  Upstream
Connection Speed 7411 kbps 1080 kbps
Line Attenuation 38 db 10.5 db
Noise Margin 12 db 6 db

Downstream noise margin has increased from 9db to 12db.
Summary, after 4wks on CN21 the only benefit is the increase in upstream speed, downstream is well short of the expected 10/12000kbps and shows signs of being less than the solid 8128kbps which I was getting with MAX.
Conclusion - BT have some work to do to deliver the expected performance.
I would been interested to know if anyone else on an 0121 exchange is seeing a similiar picture.

[#2]

I've no idea what the "configuration changes" referred to represent, but engineering work is planned on the Birmingham nodes in the early hours of 07/04/2009 and 16/04/2009 (link). However the work will lead to a break in service.
It looks like the increased target noise margin is the reason for the reduced sync speed; I guess this is an attempt by the DLM to reduce the number of transmission errors - do your stats show a high number of these?
David

[#3]

Hi David,
No my stats do not show any transmission errors, I have noticed that on a Sunday evening the downstream Noise Margin would reduce to around 6db but would be back up to 9db on Monday with a speed change, this is the first time I have seen 12db and appreciate that that would reduce the line speed. Under Max it used to run at 6db with no fluctuations and had done so for months.
I signed up to the trial because I thought my line was stable and quiet enough to show significant benefits, admittedly with my attenuation of 38db downstream the best I could expect was 12000kps and I would be happy to see 10500kps.
My feelings after 4 weeks are that BT still have a way to go before I will see any significant benefits from changing to CN21, good job this is is a trial and I signed up with an open mind.
Anyway, let see what effect the planned configuration changes have over the next couple of weeks - hopefully the result will be positive!