This is my first post here at thinkbroadband so please be gentle with me
OK so this is a bit of a stumper and because it's intermittent ZEN are reluctant to pass it on to BT just yet!
I'm using a Draytek Vigor 2820Vn on an ADSL 2+ line (G.992.5)
Sync Speed 19.7 Mb DOWN 12.3Mb UP
SNR Margin 3
Loop attenuation 22
Speed Test gives 17MB down and 0.9 Mb Up
From time to time I get no, or very slow throughput trying to load web pages. During this event the router is ramping up hundreds of ATM cell CRC errors every few seconds, even if I am doing nothing on the Internet. A BT quiet line test shows the line has no noise.
During the event the SNR Margin drops to 1
After the event the SNR Margin is back at 3 and no CRC errors and a speed test gives 17Mb up and 0.9 Down again.
The router does not need to be rebooted, but doing so makes no difference.
The effect is almost like a denial of service attack flooding the router with ATM CRC errors.
I'm guessing that it is some kind of noise or crosstalk but have no idea how to get this escalated. Since the problem is intermittent the chances of an Openreach engineer being on site during an event is slim.
Has anyone heard of, or experienced this kind of problem. Any advice or diagnostic help would be appreciated.