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[Bald_Eagle1]

PM Sent.

[NewtronStar]

I find when comparing line to others on MDWS the Hlog gives somes clues and it's SNR over the frequency tones bands.

the higher the SNR during it's journey from the lower frequency's to higher frequency's 69 Khz all the way upto 17112 Khz (17Mhz) the full D3 band) -75dB seems to be the cut-off point when FTTC ignores tones lower than -75dB

Always look at the -dB on the left hand side of the graph as the signal starts to become weaker as it travels into the higher frequency's

and you can use my hlog as a guide you will see the D3 is close -75dB and can't use these tones



 

[Bald_Eagle1]

FWIW, I have attached a copy of the snapshot montage for skynewb's connection as obtained 1st March.

We can see that DS Interleaving depth is 933, DS INP is 3.00 & DS delay is 8.

Those values will be affecting sync speed compared to attainable rate & will be adding to latency to some extent.

QLN does depict a very 'noisy' line (crosstalk and/or background noise???).
It would have been nice to know if it had always been like that.


I see from your other forum topic that you are planning to switch ISPs in the near future.
That would hopefully start you off on a wide open profile again where you could see the stats for what your line could actually achieve, unless DLM very quickly decides otherwise...........

EDIT:

Just for interest, I have also attached the Bits with SNR graph for reference


 

[skyeci]

A very big thanks to Paul. Has been a huge help in helping me find out what was going on. Even if it involved switching the neighbours modem off to identify a cross talk issue, it was nice to see my line jump all be it not for long.
Cheers

[Bald_Eagle1]

No prizes for correctly guessing when his neighbour's modem was offline & when it went back online again:-

[Bald_Eagle1]

Also see the attached animation that shows the small changes in QLN/SNR that gave fairly significant increase in DS sync speed (until DLM no doubt sees that DS SNRM is now down to around only 4.4 dB since the neighbour's line went online again.

[burakkucat]

Just a quick comment after looking at the animation.

I have never seen such a change in an Hlog plot as that which is visible at the high frequency end of the top (third) DS band. 

At present, I am unable to rationalise what we can see. 

[burakkucat]

As a result of a recent PM, I have taken another look at the Hlog plot that is currently visible on MDWS. A screen-scrape is attached, below.

Notice how the attenuation rapidly drops off just before tone 4000 ?   

I have never seen that effect before and am puzzled as to what could be the underlying cause. It looks as if there is some form inductive filtering effect taking place . . .