Any way to cap my broadband speed on ADSL2? (over ambitious profiling!)

[#1]

Adam - that's been suggested once already - for some reason he didn't chose to do that.

Quote from: Anotherone

Have you tried an alternative modem/router and filter at the Test Socket to try and eliminate those possibilities?

[#2]

Are you running the latest firmware version - ref http://www.draytek.co.uk/support/download/readme_v2820.txt
Reference:
******************************************************************************
Release Notes for Vigor2820 series
Firmware Version : 3.3.7.1 (Release)
Release Date : 10th April 2012
Build Date : 29th Feb 2012
Applicable Models : Vigor2820, Vigor2820n, Vigor2820Vn, Vigor2820Vsn
ADSL Modem Code : 232201
Locale : UK Only / Annex A Only (inc UK Annex M)
******************************************************************************
NOTE: ADSL Modem Codes
For general purpose usage on UK lines, modem code 232201 is recommened
For ADSL2+ Annex M lines, the latest modem code 2471201 is suggested
For line speeds of less than 4Mbps, on lower quality lines a modem code with more conservative paramaters, 211801 is suggested

[#3]

I have had a similar problem for a couple of months and Plusnet have adjusted my line profile to have a target noise margin of 6db, but it took a long time to become a permanent feature.  In reality, this results in noise margin that fluctuates between 3db and 9db but the main thing is, the connection is stable.  Previously, the exchange and my modem would aim for 3bd or even 1db at which point, the line became unusable.
Might be an idea to run routerlite on your PC to monitor noise margin and connection speed.  It handles a larger number of router/modems. Set it to capture graphs to jpegs (and maybe data to a logfile).  You then get a visual indication of the ups and downs of your noise margin over time and can cross reference with the disconnections reported by Plusnet.

[#4]

fwiw, I've been trying to get the target noise margin raised on my line from 3dB to 6dB.
Unfortunately, it fails to stick at 6dB following an SNR reset, and eventually reverts back to 3dB after a few days.
PN now trying to apply an banded profile to my line to limit the line speed to no more than 6,656kbps for past week, but so far it has not worked at all and line speeds continue to hit as high as 7,800kbps during the day if I have to resync the router.  Next review of my ticket is tomorrow.
If a banded profile is successfully applied, I am wondering whether DLM will eventually remove it after a few days given the above experience with the target noise margin failing to stay at 6dB over the past fortnight....

[#5]

Quote from: zzZzz

Unfortunately, it fails to stick at 6dB following an SNR reset, and eventually reverts back to 3dB after a few days.

That was the problem Plusnet/BT were having with my line. Fingers crossed they have sussed it this time.  Have been at 6db for over a week.

[#6]

Quote from: ClashcityRocker

It's an annoyance that my broadband is useless until I reboot it again because of the silly profile it's given

What do you mean by the silly profile? Where are you seeing this profile?
Jojo

[#7]

I think he's talking about the sync speed - when it is "too high". From the few stats that have been posted, the "bad" is showing an SNRM of 2dB.
I suspect that when the margin drops this low the error rate goes through the roof and slows the throughput - but that's only a guess as the OP hasn't posted any CRC or other error figures for us to look at, just made a comment.
As the OP hasn't posted for 4 days, perhaps he's getting round to trying some of the suggestions that have been made days ago, like checking in the Test Socket, checking he's got the latest firmware, comparing error figures when it's "bad" with another modem/router, resyncing late in the evening and leaving it connected. There again, maybe the builders have cut him off altogether!

[#8]

First time I've seen router stats with a connection rate higher than the attainable (max) rate, although nothing in computing suprises me anymore.
From the two sets of data posted this is the BAD scenario. When reporting a GOOD link, connection rate < attainable rate.

[#9]

Oh surely not  and you must have seen the ones where the download information is shown as the upload and visa versa and the Line attenuation is shown as the Noise margin and so on 

[#10]

Commonly referred to as a feature rather than a bug 
I would go along with your thoughts but in this case the figures do seem to correlate.

[#11]

Could it be another firmware bug then? - I didn't read the bug fixes in the latest firmware info - it may be one that's been fixed, or been introduced by that update perhaps?

[#12]

Could well be a firmware issue, as this particular model has had at least 12 updates (which seems rather alot).
Without knowing the OP's version we can only guess.