Why does it do this :((

Despite being up for 4 days+, my router was rebooted this morning at 12:30 and when it came back up my sync speed had dropped ~100k. Its done this several times despite the SNR not dropping below 8.5db even at night. It seems that every time the router reboots, the sync rate drops despite not appearing to suffer a SNR problem. Does this indicate a hardware issue or something dodgy BT are doing (DLM?)

I've attached screenshots from RouterStats Lite of (1) SNR dropping to its lowest at night and (2) what happened this morning.

SNR at its lowest

After reboot

Edited by deleted (Wed 16-Mar-11 18:07:53)

Jon

Did you mean 12:30 this afternoon or just after midnight? Midday is the best time

Your default noise margin has been set to 12dB, if your ISP could be persuaded to reset the noise margin to its (if BT based) default of 6dB you could gain about 1Mbps.



Ian

I meant 12:30 this afternoon (just after mid day). I'm 9 days into my second 10 day training period. I persuaded my ISP (Plusnet) to start the 10 day period again as I'd had a years worth of line faults which were finally fixed last month.

Its rather odd that the default SNR margin has been raised to 12db as the line had been happily syncing at 2.000 for several days, then the router was accidently rebooted and when it came back up it resynced at 1.600ish. I'm quite surprised that the DLM took action to raise the SNR margin after just one reboot, the line hadn't been up/down at all.

Should it reset itself back to 6db after a period of stability or will I have to ask Plusnet to do this?

Regards

....... then the router was accidently rebooted and when it came back up it resynced at 1.600ish

That can happen if the reboot was between 3.30pm and 10.30am (especially so on some long lines), it's best to leave the router on 24/7 and avoid a router reboot although one in 24hrs shouldn't be too detrimental unless the line is flaky.

It can also be raised if you have lots of errors

Yes nuber of errors can increase the target noise margin.

IAN