Recent sync drop on my line

[#1]

Hey folks, first post so hello all!
A bit of background, moved here 4 years ago or so (from my parent's house, who still have their constant 8 meg sync, grrr!) and even though I stay quite a distance from the exchange I was really happy with my 4600-4700 sync speeds, my attenuation always sat at 47dB. Over time this rose to 48dB and my sync tended to hover around 4200-4400 but I was still happy.
The other night I happened to look at my router stats and noticed the attenuation had gone back down to 47dB. "Great!" I thought and powered down my router and left it a wee while and powered it back up, but all I got was a nice 3200 sync?! I left it a while and tried again, but over the next few days all I could get it to was around 3500.
Anyway, my question is ("finally!" I hear you cry) my attenuation is still solid at 47dB but my noise margin is now sitting between 13dB and 15dB, is there any way I can convince the exchange to give me a lower noise margin again and get back up to the speeds I was seeing before this? I'm not even sure why the exchange has decided to do this. My connection has never been unstable, in fact I'd got so far as to say apart from 2 instances over the years where I got stung by the blip thing and ended up at 250Kbit for 3 days it has been rock solid since setting up.
Cheers
Gordy

[#2]

raise a ticket asking for your snr target to be reduced and PN will get onto BTw who should set the snr at the phone exchange for you.
but if there is a fault on your line causing low sync events the snr target will raise again.
you can also try the dmt as i adviced on this post. http://community.plus.net/forum/index.php/topic,73266.0.html

[#3]

Your attenuation figure should normally never change, so it could be that there was some temporary interference on the line which led to a high error count or connection dropping, and the exchange automatically put your noise margin up to compensate. If it was a temporary issue then your noise margin should go down bit by bit over time and get you old sync rate back. Try restarting your router every day or two (no more often) and see what happens. It could take a week or so to come back up. If you reconnect too often it can be counterproductive as the exchange will see it as a high disconnection rate and will keep your noise margin up.
Edit: Asbodog beat me to it! I would question raising it with BT at this stage, as they can be reluctant to lower the margin more than occasionally. Give it some time, and if it doesn't come back up then raise a support ticket.

[#4]

I think the blip thing got me 

[#5]

Hi Gordy,
Are you wired directly into your master socket?  Are all of your used telephone sockets filtered?
Have you had a look to see what your noise margin is currently sitting at.  Has this changed since you last looked?

[#6]

Hey folks, thanks for the replies!
James, yeah I only have one splitter directly into the master socket, router is fed direct from there along with a single phone feed into my cordless phones. That's all I have connected to the phone system, no extensions at all.
My noise margin is still hovering between 13 and 15dB, attenuation still solid at 47dB, hasn't changed since I noticed is coming down from 48dB last week. Sync speed is still 3552kbps but then it wouldn't normally resync without a reboot and I'm not at home just now so can't power cycle the router, just checking the admin page remotely till I get home tomorrow night.
My line has always been stable with a much lower noise margin as I say so not sure what has prompted the exchange to up my limits.
Cheers!

[#7]

PN may ask you to supply some line stats via  ticket showing the status of your line. Look at them for sudden random dropped connections.
PN have recently been assisting me with changing my SNR, so far this if is the 3rd reset and going well judging by tonights stats.
Try routerstats and use the log file to monitor you line stats over a period.
Router stats http://www.vwlowen.co.uk/internet/files.htm
podman