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[jeffbb]

Hi
Looking at the bitswap/tone graph the biggest swaps correspond to the most noisy channels

Tone 211 is almost certainly radio 5 (910 KHz).
tone 185  could be Classic Gold or R Ulster (Foyle)  if you are within range of either of these
see   mw radio stations

the higher Tone  at about 280 I cannot get its frequency on mY adsl1 line

these tones on the bitswap graph would show low bit loading (difficult to see on Post) .They would show a low  SNR/ SNR margin on the appropriate graph  ,indicating Noise The exact opposite to your first worry about the SNR spike .

Most of the other tones(not all)  on the bitwsap/tone  graph are the (good swaps) the tones that took the data that could not be handled by the tones with high noise .

Next time you start RS its worth looking at that graph ASAP . you should notice the swaps more or less happening in pairs .

What does the RS stats tell you about YOUR actual connection (ADSL 2+ G.992.5.?)

Regards Jeff

[solorize]

Jeff,

Thanks for all the info on the frequencies, very interesting.



Please see my Router Stats below:

[solorize]

After letting RouterStats run for 5 days
I have the following Stats.

Does this look ok? or are the amount of Bitswaping high?

The FEC Erros (down) seem to be very high at 639,181,353
I know its ok to have a high'ish amount but this figure does seem
very high.

I also noticed that the SNR for the downstream varies between
min 6.5dB to max 9dB. (as shown in the last image), does the router
automatically adjust the SNRM? even tho my ISP has set it to 6.dB.


Bitswap:



RouterStats:




Min Max SNRM:

[geep]

Hi,
I calculate your CRC error rate as 1.9 CRCs per minute.
This compares with my router's error rate of anywhere between about 0.2 and 7 per CRCs per min.
Seems an OK figure.

Your FEC error rate is about 82,000 FECs per minute.
My router currently registers about 4,000 FECs per minute, and usually in the range between 3,000 and 10,000.
I guess your router is just working away happily correcting errors - maybe others know more on this.

It's interesting that your HEC errors are a very small value.
I always see HEC errors about 10% less than the FEC errors.

The SN Margin range between 6.5 and 9 dB seems pretty typical.
Mine drifts down every evening from a nominal 9 to about 6.5, and whilst I'm abed drifts back up to 9 again.

No particular comment about the bitswapping. I found the RouterStats visualization a bit difficult to digest so
invented my own views - http://tinyurl.com/39dgbrd , http://tinyurl.com/3xgm2sl & http://tinyurl.com/mxstld

Cheers,
Peter

[solorize]

Hi Peter,

Thanks for your reply.

I have had a stable line for 5 days now, so guess that the FEC errors
are not effecting the router too badly.

I have to admit that looking at my ADSL stats is starting to get adicitive lol.

The visualizations you have are great! was it easy to set up? and does it pull
the data straight from your router or do you have to have RouterStats running
and saving the info to a data file which then can be read by the visulizations?

Mark

[geep]

Hi Mark,

Initial visualization was straightforward to setup, but grew over time and is now a bit complex to maintain.
Uses cronjobs, bash scripts, Perl, flot, gnuplot, ImageMagick and PovRay.

RouterStats didn't support ST546, so made own Perl scripts for logging - 99% from Jason Lassaline's work - and own scripts to drive gnuplot, flot and PovRay. Only took a couple of days to support a different router - 2Wire 2700HGV. Logging runs on either Linux or Windows

RouterStats now supports ST546 so could use RouterStats log files, not sure if bitloading logged. But doesn't run natively on Linux - a prerequisite.

Postprocessing only on Linux. and is heavy on cpu, PovRay 3d graphics especially. Ought to 100% rewrite this for portability / maintainability.

Cheers,
Peter

[jeffbb]

Hi
Quote :"does the router automatically adjust the SNRM? even tho my ISP has set it to 6.dB."

The router does not adjust the SNRM as such.
Very basically . When a connection is negotiated the amount of available data bits is calculated from the total SNR - target SNR . This gives the max synch attainable (some bits to spare for bitswapping ).

At that point (immediately after synch the SNRM ~= target SNR ). The SNRM will then fluctuate depending on the increase / decrease of the noise  on the line . Its not your  Router or DSLAM actually changing the SNRM it is the result of the changing conditions of the connection .

So if noise on the line increases by 3db then the SNRM deceases by 3db and vice versa.

If the noise in particular tones  increases then the first step to maintain the connection may be to swap data to another tone (bitswapping ). If the noise gets too bad in a particular tone ,then that tone will be marked as unusable . Obviously if the noise gets so  bad that many tones  are unable to be used  then there won't be enough tones to maintain connection .

a much more comprehensive explanation
Regards Jeff