My expierence so far,

[#1]

Hi Group
My line went live on the 6th April, On the 5th I was knocked off my motorbike, and hence spent time in Hospital,home now
with a Zimmer for transport,so rather late in  posting my results
I use a Netgear DG834 ver3. with DGteams firmware,My line att is 40 db (but very stable) so don't expect much above 11meg
downstream with 6db s/n, here is my current Routerstats results
      ADSL Link
  Downstream
      Upstream
  Connection Speed
      8392 kbps
  1001 kbps
      Line Attenuation
      40.0 db
      24.7 db
      Noise Margin
      7.3 db
      5.7 db
For the first 2 weeks my router was in ADSL1 mode,with no use as I was not home,Since changing to ADSL2+
I have found that the Dslam tries to hard to get an upstream speed of about 1 meg, at the expense of Downstream speed
I did have once have a downstream of 10meg plus,at 6db s/n, with upstream at 750 odd,and it stayed there all day until we had a power cut that evening
Is there a way I can have upstream capped as I don't really need it ,and prefer the faster downstream my line can handle
TYIA
M Wright

[#2]

Quote

Is there a way I can have upstream capped as I don't really need it ,and prefer the faster downstream my line can handle

now theres a first.
i belive PN can place an order to place you on capped upstream think its fixed at the old rate of 448.
but to date i have only seen orders placed to remove people from capped upstream that were placed wrong when first ordering the line for adsl2+.

[#3]

Sure - I can cap your upstream to 448Kbps if you would like me to do so.

[#4]

Hi
Thanks for your reply.
I ask as my upstream speed that  it sets,  does seem to limit my downstream speed?
DMT  states I am getting 82%  of my available downstream speed, my line should  be able to
handle, My Netgear is well capable of holding on to a  s/n of 3db or less, (with ADSL1 at least )without dropping the line 
I have no need for the extra upload speed, but if you prefer I am willing to wait ,,,to see what happens as time passes,
and reduce it later if downstream stays around 8 megish.
My BT profile has not not moved from 6500 since I have been on 21CN, (although you have manually changed it to 8meg you end,)
is it stuck or just slow to change,I thought this system was rather better in that respect
TYIA
M Wright

[#5]

Not sure whether limiting your upstream speed will improve downstream speed.
As I stopped my line being upgraded to DSLMax I have no previous experience how that system work but from my experience since being upgraded to the ADSL2+ trial from a fixed 2Mb connection are:
1. Negotiated an ADSL2 connection as the line attainable rate never exceed 6500Kbps
2. The sync rate is 80% of the attainable rate when the SNR (not margin) is at it's best.
3. The SNRM is maintained at 6dB with the attainable rate fluctuating.
4. When the SNR is approaching it's worst the 6dB is just about maintained but with a reduced attainable rate and the sync rate will approach 100% of this rate.
5. When the SNR is at it's worst the attainable rate is less than the sync rate, seen mine at 110% and the SNRM go below the 6dB to approximately 3bB.
So not sure from my observations why the SNR margin is increased as it seem to me that the important factor is how much the attainable rate fluctuate during the day and select a sync rate less than the lowest attainable rate with a 6dB margin.

[#6]

Hi
Thanks for your post
All I can say is on the occasions when it has connected at a lower upstream rate say 750 or below,
The downstream has been 10megs+ at 6db s/n .Trouble is if it acts like the upto 8meg line I was on,
giving my router a resync always caused the Dslam to raise my s/n ratio to 12db or even more,
Before I could control this via DGteam or DMT software but I have read here that, that no longer works,
So am reluctant to tinker with it , unless you know better?
TYIA
M Wright

[#7]

snr tweaking does work but dosent seem to allow you to tweak as much.
when i tried routerstats tweaker i set it to 12db down from 15db it only snyc'ed at around 14-13db
so if your using dmt or dgteam drop the percentage a bit lower than you would on adsl to get the same effect

[#8]

Hi Asbo
Thanks for that ,I used DGteam as it was already set at 50% has been for yonks
I needed to turn  it down to 5%!. to get a rise to 8743 down and now at  973 up
seems the lower up ,gives me more down?
      ADSL Link
  Downstream
  Upstream
  Connection Speed
      8743 kbps
  973 kbps
      Line Attenuation
      40.5 db
      24.8 db
      Noise Margin
      6.4 db
      6.0 db
TYIA
M Wright

[#9]

Quote

I used DGteam as it was already set at 50% has been for yonks

do you know what your normal target noise margin is on adsl2+ or have you used the 50% tweak all the time youve been on the trial.
i ask as i am wondering what drop in snr a 5%  tweak got.
if you dont know dont bother trying to find out as i dont want you  at me if your ip profile drops.

[#10]

Hi Asbo
I don't know what my normal target s/n is ,as my router was already set at 50%
when I had the bike crash, so it stayed there all the time I was in hospital,
Today my line has gone up  to
    ADSL Link
  Downstream
  Upstream
  Connection Speed
      8919 kbps
  855 kbps
      Line Attenuation
      40.5 db
      24.8 db
      Noise Margin
      6.4 db
      6.4 db
Seems the Dslam adjust  itself live,  with no need for me to force a Resync am I right
I still believe my BT Profile is stuck at 6500 though (BTspeedtester busy ATM)as my throughput is 6500 and not a byte more
Later