Sync Speed keeps dropping

[#1]

Hi,
I have raised a fault call for my routers sync speed. Up until the begininning of may this year it was very stable at 3400 to 3600. Now it randomly drops to around 1800 and then goes back to normal.
Nothing has changed in the house and the router is same as it was before. The devices connected to the router are also the same with no config changes.
I am a bit worried that the fault call is starting to go off track as I am being asked to do BT speed tests which don't seem to have any bearing on the fault. It is not the speed my PC / laptop connect to the internet that is the issue , it is the sync speed on my router.
Could someone have a look and advise.
Thanks for your help
Thanks.

[#2]

Can you run a bt speedtest at http://speedtester.bt.com/ and a speed test at http://www.mybroadbandspeed.co.uk and post the results.
Also the stats from your router would be useful, how to get these can be found here http://www.kitz.co.uk/adsl/frogstats.php

[#3]

Hi,
thanks for responding
currently
Modem Status Connected
DownStream Connection Speed 3296 kbps
UpStream Connection Speed 448 kbps
VPI 0
VCI 38

ADSL Link Downstream Upstream
Connection Speed 3296 kbps 448 kbps
Line Attenuation 57.0 db 31.5 db
Noise Margin 8.3 db 20.0 db
Will add BT speed test when can next do one

[#4]

Hiya - Just to say, those stats look good for the length of your line.
What do you get from http://mybroadbandspeed.co.uk ?

[#5]

Is it the sync speed that is dropping to 1800 or your speedtest ruselts?
If it's your synch then there might be some kind of interference that causes it.

[#6]

As requested speed test results
Date Download Speed Upload Speed 
Today 19:45 1621 kbps (203kB/s) 382 kbps (47.8kB/s)

In answer to the second question it is my sync speed that drops, which then leads to my IP profile dropping to about 1500. My sync speed then recovers to 3400 -3600 roughly giving me an IP profile of 2500 or 3000 once things catch up again. I have not really bothered with speed test results as they just match my IP profile at the time.
Until the sync speed drops started I normally had 3400 to 3600 with 2500 or 3000 IP profile. Nothing has changed in the house or the room my broadband router is in. I was wondering if it was a BT fault of some sort.

[#7]

Yesterday I powered of all electrical devices in the room except for the PC, screen and router.
Also configured a spare router to use instead of the existing one.
After a reboot the router sync'ed at 3200
Today at 16:30 the router was still sync'ed at 3200.
Today at 17:30 it had dropped to 2400.
Changed both micro filters and also the ADSL cable which is a short one the same as before.
Rebooted router and the sync speed in 3200 as before.
This does not look like an interference fault as nothing has changed from before except I have powered off more electrical devices.

[#8]

I have now plugged my router into the test socket to see what happens. All phones etc are now disconnected.
Will now wait and see what happens.
Trying the following made no difference so far :-
Different routers
New microfilters
Powering off all nearby devices
New ADSL cable
Routed ADSL cable well away from any other cabling etc
There are no devices near to the router or cabling.
Nothing has changed in the house in May to cause the issue.
Until the begining of May I did not have any sync issues at all and always had a very stable sync speed.
This is starting to look like a fault external to the house ie BT.

[#9]

A word of advice. Before you go changing any more filters, disconnecting the modem/router from the filter or unplugging the faceplate etc. ie anything that will cause the modem/router to lose sync, power it down and wait a few minutes before disconnecting the line in any way. I'd also avoid doing this more than about 5 times in any hour, and then leave it alone for the rest of the day. This is to try and avoid the exchange DLM thinking you have a line problem and raising your Target SNRM which will result in slower sync speeds.
Can you post the current ADSL link data from the modem/router? Do you leave it on 24/7?
Based on your earlier reports can you advise whether the sync speed recovered "by itself" or did you reboot, or was this the next time you switched on if not on 24/7?
When you mentioned that the speed had dropped to 2400 at 17:30, was there a thunderstorm?
Can you hear any crackling or other intermittent noises on your phone line?
If neither of those last 2, have a think about any electrical equipment that may have come on around 17:30 ie boiler for hot water, fluorescent or energy saving lighting, etc etc.