Hi - on saturday replaced 2600 series ADSL router with new 2820 version.

Old set up (wiring etc) not changed.
Old sync speeds range 2500 to 2800. (download (2000)) Worked OK.

Set up new 2820 box - first seen sync speed was 3400 (looking good)
After first re-boot sync now 2800 ish (hmm...)
2nd re-boot - sync now 2400 ish (eh?)
3rd reboot - sync 2100 ish (oh no)
4th reboot and subsequent re-boots - sync not 1780 to 1980 range (how nice ....)
So - it was OK - wires not changed - so why did it keep dropping ?
Have tried new wirings / and wireless on/off - nothing helps - stuck at low range (I now get 1500 download).
Has the box got a fault or is it software taking a dim view of my adsl phone line ?

Hi,
I too tried a 2829VN and, like you, was impressed with the first sync spped, about 550K faster than my previous router.
However, every time you have to change a setting on the 2820 it has to restart and this I think is where the problems start. I don't think it does a clean disconnect, i.e. a PPP handshake and therefore BT's (and I'm assuming you are in the UK here) dynamic line monitoring software thinks that there is a line problem and so drops the sync speed to try and stabilise the line. if you leave it for a few days (Plusnet say 72 hours) without disconnecting at all then you should see the line speed creep up again? but then again, you may not

It's a theory and it seemed to work for me but I also exchanged the 2820 for a Billion 7800N
Now synchronizing at over 7,000 KBps where the Vigor managed just over 5,500Kbps Don't know what that means in reality but I'm guessing it has to be good

Yep - sure as eggs ... after a week or so the sync crept back up - not as good as the old router (was 2750) but now getting 2580. BRA limit this to 2000 but that is BT for you.
Had new firmware from Draytek - made no difference.
Had Zen (ISP) look at it - made no difference.

Caused by : to set up the 2820 you need to re-boot a few times - but this interacts with the software (a) in the 2820 (b) at BT excahnge. These decide between them that "due to all the recent line breaks the line is very bad - so must slow down to be sure ...." This is akin to a motorway queue when nothing is actually stopping the traffic. Takes time to clear - say a week.

Looks like the Draytek 2820 is very conservative and wants an ideal line - any noise or breaks and it pulls back the sync. to make it more secure (and slow). Eventually the BT side ups the sync. This is 2010 progress folks !

I think the 'R' in RADSL stands for random.

thanks all for your help/comments.