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Effect of mains or something else interference on sync speed

Community Veteran
Posts: 38,460
Thanks: 1,031
Fixes: 62
Registered: ‎15-06-2007

Effect of mains or something else interference on sync speed

Router stats just after a short (5 – 10 sec) power cut
Noise Margin:    2.5  dB (default noise margin 6dB)
Connection Rate:  5536  Kbps
Line Attenuation: 51.0  dB
Power:            19.5  dBm
Max Rate:        5824  Kbps
No way is that going to hold up so  Sad
Resync with 5dB default noise margin
Noise Margin:    5.1  dB
Connection Rate:  4928  Kbps
Line Attenuation: 51.0  dB
Power:            19.4  dBm
Max Rate:        5216  Kbps
Much better  Grin
7 REPLIES
quelquod
Aspiring Pro
Posts: 544
Thanks: 66
Registered: ‎31-07-2007

Re: Effect of mains or something else interference on sync speed

Quote from: Oldjim
Router stats just after a short (5 – 10 sec) power cut
Noise Margin:     2.5   dB (default noise margin 6dB)
...

I've just shifted to fibre but for the last year or so I've been running consistently with a margin of 3dB.
For some time my default had been 6dB but after BT fixed a noisy line problem it reduced to 3 without any input from me.
I don't think a low margin is necessarily a killer (and another 3dB gives you just that bit extra) as long as it's steady.
Perhaps your resync coincided with a particulary quiet period?
Democracy - 3 wolves and a lamb voting about what to have for lunch!
Community Veteran
Posts: 38,460
Thanks: 1,031
Fixes: 62
Registered: ‎15-06-2007

Re: Effect of mains or something else interference on sync speed

Nope - it always does that after a power cut and there is no way my line is stable at that speed or noise margin
It actually clocked up 3000 uncorrected errors in the minute or so before I initiated the reync
Community Veteran
Posts: 19,102
Thanks: 443
Fixes: 21
Registered: ‎31-08-2007

Re: Effect of mains or something else interference on sync speed

I think he meant your resync coincided with a quiet period, which actually it undoubtedly was, albeit very brief. You no doubt resynced ahead of many of the other local modem/routers so the crosstalk from their lines and hence background noise was lower, so the margin would have been greater if you'd been connected at your normal speed. Once the others came back on line, down goes the margin.
Community Veteran
Posts: 38,460
Thanks: 1,031
Fixes: 62
Registered: ‎15-06-2007

Re: Effect of mains or something else interference on sync speed

Just to rub it in
My exchange is fibre enabled and guess who's cab isn't on the list  Sad
quelquod
Aspiring Pro
Posts: 544
Thanks: 66
Registered: ‎31-07-2007

Re: Effect of mains or something else interference on sync speed

Quote from: Anotherone
I think he meant your resync coincided with a quiet period,

Yes, that's what I meant of course.
I used to monitor noise fluctuations and it was surprising how much they could vary.
I managed to persuade BT that my line's noise was very weather-dependent and they found (I think) a faulty surge arrester on my pole.
Democracy - 3 wolves and a lamb voting about what to have for lunch!
Community Veteran
Posts: 19,102
Thanks: 443
Fixes: 21
Registered: ‎31-08-2007

Re: Effect of mains or something else interference on sync speed

Never mind Jim, at least you've got 21CN and we haven't a cat in hells chance in the near future  Cry
BRABUS
Grafter
Posts: 660
Registered: ‎12-01-2010

Re: Effect of mains or something else interference on sync speed

Why haven't you got a cat in hells chance?