Problem with new line - sync speed drops over time

I wondered if anyone can give an thoughts on a problem im having with my new broadband line...

Recently I moved to the property next door to where i used to live. At the old house I could get around 6.5 meg and Zen quoted the line in my new property should get very similar. The master socket is actually in the loft, on the inside of the gable. There is no internal wiring what so ever, no phone, and I have removed the master socket face plate and plugged directly into the test socket.

I keep finding my equipment will sync at a good speed and then over the course of a few hours will drop real low. The sync speeds keep dropping so low the Bras profile is ADSL500 and im only getting download speeds of around 0.35 meg.

I have tried 3 different pieces of equipment, all with the same results:

Vigor 2820n router - sync (448000 up / 8128000 down) SNR (10) Loop Att (27)
Vigor 120 modem - sync (448000 up / 5216000 down) SNR (6) Loop Att (29)
Netgear DG834G router - sync (448000 up / 7616000 down) SNR (10) Loop Att (27.5)

The above stats are shown when the devices have first connected, then the speed drops signficantly over a few hours. The connection does drop now and again also.

Any idea what could be causing it to sync at a good speed upon start up then decrease over time

What would be typical expected speeds for my SNR & Loop Att figures, typically 10 / 27?

I have also tried different filters & RJ11 leads.

Your SNR/Attenuation should give you around 8128kbps or very close.

Have you plugged a phone in and listened for noise on the line.

You might want to try routerstats from http://www.vwlowen.co.uk/internet/files.htm to give you a view of what happens overtime.

I would phone support if you are out of your 10 day training period - they should be able to see the connection history and check the line. Might be a faulty line card at the exchange.

Thank you for the information.

I will borrow a phone from somewhere and have a listen for noise. I will also get the router stats software running tonight if I can to try and get a bit more detailed information.

I am 6 days into the 10 day training period

Ignore the training period, the line will continue to adapt as it is now for ever.

Unless it settles into a 15dB target noise margin and this makes it immune from the noise bursts

Thanks Andrew

Would you regard it as normal however to sync at 8 meg each time the router is started and then slowly creep down to half a meg? If the line is bad why doesnt it sync at say 0.5 meg straight from booting the router?

The only reason I mentioned training period is that Zen are reluctant to act on faults within this period.

Because the bad stuff is usually random noise.

Some routers are not very good at handling this scenario, and as the noise shifts around do not re-use the non-noisy bins. Classic case of ensuring you have what people consider to be the best firmware for each model.