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QLN Graph

jafreer
Rising Star
Posts: 832
Thanks: 49
Registered: 13-10-2012

QLN Graph

Looking at the attached QLN graph, there seems to be a large chunk marked as 'other' (in blue).
There is a small amount of upstream at the start (in green), but the rest is blue.
Does anyone know what this 'other' refers to? I could understand better if it was a flat line, but it actually looks like it is captured data of some sort.
There is nothing after 3100 as there are no tones carrying data after that, but there is no data being carried where the 'other' part is graphed either (according to the bitloading graph).
So I just wonder why this 'other' part is showing any graph at all - I would expect nothing to be there, just like above tone 3100.
Thanks for any input.
4 REPLIES
Community Veteran
Posts: 1,412
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Registered: 29-01-2009

Re: QLN Graph

IIRC, DSLstats has to guess at whether a frequency is downstream or upstream - and it uses data from some of the other graphs to figure it out.
If a frequency is marked as "other", I think it means that it couldn't work out that the frequency was a definite upstream or a definite downstream, so it just labels it as "other".
Plusnet Customer
Using FTTC since 2011. Currently on 80/20 Unlimited Fibre Extra.
jafreer
Rising Star
Posts: 832
Thanks: 49
Registered: 13-10-2012

Re: QLN Graph

Thanks for that reply. What is curious is that there is no upstream data used where that part of the graph is, just like there is no downstream data used above tone 3100. So why does it show anything at all, irrespective of whether it knows if it is upstream, downstream, or other.
There is no graph line above tone 3100, presumably because no data is carried above tone 3100. But no data is carried from about 2050 up to 2800, yet a line is shown. There is a tiny amount of upstream shown from just below tone 2000, to about tone 2050, yet that line carries on marked as 'other'.
The blue line is in an upstream allocation.
Don't get me wrong, I am not having a problem with this, I am just curious and wish to understand it Wink
Community Veteran
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Registered: 10-06-2010

Re: QLN Graph

I think the advanced data, for the HLog and QLN graphs, is collected while the VDSL2 connection is being established. It would be measured for all possible frequencies, the measuring is probably done before which frequencies are usable to carry data and which aren't has been determined.
jafreer
Rising Star
Posts: 832
Thanks: 49
Registered: 13-10-2012

Re: QLN Graph

ah ok EJS, that makes sense. Thanks for the explanation - much appreciated.