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SNR slowly drops

Community Veteran
Posts: 1,653
Thanks: 69
Fixes: 2
Registered: ‎17-06-2007

SNR slowly drops

Im on a Thomson V8 provided by PN as my old V7 seemed to be getting a bit tired. The new one is better but there is something very odd - over time the SNR drops slowly. When I connected over 5 days ago the SNR was about 7 (and I connected at 448 / 5,088 ). The SNR has now dropped to 3,5 and the connection is still holding (even though the FEC is now 165 / NA). 
Previously my SNR dropped in the evening and then rose in the morning  as I'm on an overhead cable but this recent behaviour is very odd.
26 REPLIES
Community Veteran
Posts: 38,460
Thanks: 1,031
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Registered: ‎15-06-2007

Re: SNR slowly drops

It sounds like a bit swapping problem
Community Veteran
Posts: 1,653
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Registered: ‎17-06-2007

Re: SNR slowly drops

So how do I troubleshoot that?
Community Veteran
Posts: 38,460
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Registered: ‎15-06-2007

Re: SNR slowly drops

I have no idea with that router - when I had that problem a reboot fixed it
matt_2k34
Grafter
Posts: 1,300
Registered: ‎09-07-2007

Re: SNR slowly drops

most routers you can turn bit-swapping off..
If the connection doesnt drop, dont worry about it?
Regards
Community Veteran
Posts: 1,653
Thanks: 69
Fixes: 2
Registered: ‎17-06-2007

Re: SNR slowly drops

Well I was sort of thinking that  - the speed is fine and its solid so why worry, unless it screws my profile of course
matt_2k34
Grafter
Posts: 1,300
Registered: ‎09-07-2007

Re: SNR slowly drops

Will only if it drops loads of course Smiley i wouldnt worry just yet
Regards
Superuser
Superuser
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Registered: ‎06-04-2007

Re: SNR slowly drops

Are you aware you can got plots of bit loading and bit swapping activity on this router using RouterStats?
David
Community Veteran
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Registered: ‎17-06-2007

Re: SNR slowly drops

Yes I am aware - and here is a screenshot.
Not that it means much to me ;-)
Community Veteran
Posts: 38,460
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Registered: ‎15-06-2007

Re: SNR slowly drops

does the bit swaps over time tell you anything
Community Veteran
Posts: 1,653
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Registered: ‎17-06-2007

Re: SNR slowly drops

Not sure.
I only powered routerstats up this morning
Community Veteran
Posts: 38,460
Thanks: 1,031
Fixes: 62
Registered: ‎15-06-2007

Re: SNR slowly drops

Usually the bit swapping would have happened earlier in the morning - this is mine (computer on sleep overnight)
However bit swapping is clearly working.
If it continues throughout the day and doesn't settle down then you just have a line with a bit of random noise on it
Do you want to remove your IP address from the picture
Community Veteran
Posts: 1,653
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Registered: ‎17-06-2007

Re: SNR slowly drops

Would it make sense to restart it and then leave Routerstats running?
The SNR has risen slightly this morning to 4
Speedtest shows this:
Community Veteran
Posts: 38,460
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Registered: ‎15-06-2007

Re: SNR slowly drops

The odd thing about that test is that your IP profile should be 4000kbps
You could do a resync and see what happens.
If you want to monitor over night you would need to keep the PC running
Community Veteran
Posts: 1,653
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Registered: ‎17-06-2007

Re: SNR slowly drops

OK I've restarted everything
Maximum Bandwidth (Up/Down) [kbps/kbps]:	908 / 5,280
Bandwidth (Up/Down) [kbps/kbps]:         448 / 5,088
Data Transferred (Sent/Received) [kB/kB]: 0.00 / 440.00
Output Power (Up/Down) [dBm]:                 11.5 / 19.5
Line Attenuation (Up/Down) [dB]:         29.0 / 48.5
SN Margin (Up/Down) [dB]:                 22.0 / 6.5

Routerstats running and I'll leave my computer running for the next day or so
As for the speedtest result - its very odd : I usually get 3.7