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Bits/Per tone graph - Does it look right?

ComplexP
Grafter
Posts: 98
Registered: 02-10-2009

Bits/Per tone graph - Does it look right?

Hi All
This is kind of a question that has arisen in a previous thread. I've been on the 21CN trial now for quite some time and have yet to see any improvement in my downstream sync rates (upstream seems to have doubled but is currently capped in a unsuccessful attempt to increase downstream rates). I'm no expert in this technology so I was wondering if someone could take a look at this bits/tone graph and let me know if it looks reasonable for a 21CN connection:

Any idea what those light green lines mean?Huh
EDIT: Sorry for the poor quality, I cant seem to get the image to size correctly. A clearer version can be found on the original thread. Just scroll to the bottom
http://community.plus.net/forum/index.php/topic,80005.16.html
Thanks all.
8 REPLIES
scootie
Grafter
Posts: 4,799
Registered: 03-11-2007

Re: Bits/Per tone graph - Does it look right?

the extra green lines will be jus where routerstats is geting its knickers in a twist and reporting them as upstream bits.
the benfit of having the bits/tones graph is mainly comparing what tones have come back in to play or bein knocked out of use say when you try a resync with out a dect phone pluged in ect ect.
as your graph pretty much sweeps down smooth with out any chuncks of tones missing. its a case mainly trying to bring the higher freqency tones it to best possable use. but that can be a losing battle to fight
below adsl2 on 49db atten 12 db noise margin was 51db on 20cn, adsl2 at 15db noise, and a dmt capture of my line on adsl 20cn max preminum (832kbps upsteam).
on all but 1. tone 48 is nxt to useless on my line. am of th opion that the interfence source is outside as on ocassion's it comes into play but follows no pattern what is switched on and off in the house
ComplexP
Grafter
Posts: 98
Registered: 02-10-2009

Re: Bits/Per tone graph - Does it look right?

Quote from: ASBO
the extra green lines will be jus where routerstats is geting its knickers in a twist and reporting them as upstream bits.

Thanks Asbo, but if you look reeeeeally close, you may notice that some of those lines are light green and some are dark green. I wonder why...?
scootie
Grafter
Posts: 4,799
Registered: 03-11-2007

Re: Bits/Per tone graph - Does it look right?

didnt notice but looking closer they indeed are. still think its just routerstat playing up.
i can get it to happen on version 5.0c by refreshing the graph till it happens.
Superuser
Superuser
Posts: 9,761
Thanks: 1,147
Fixes: 62
Registered: 06-04-2007

Re: Bits/Per tone graph - Does it look right?

Light green tones show where bit-swap has occurred since (I think) sampling started. This marking highlights tones/frequencies which are affected by interference though I think without specialist kit trying to identify the cause is a matter of trial and error (and it might well be external anyway).
I was surprised to see significant effect on upstream tones. It's very rare to see an upstream bit-swap on my plot though I'm still on IP stream max. ADSL2+ not due until next year.
As far as (lack of) improvement in downstream sync speed with ADSL2, since tones above 160 contribute little to throughput it is not really surprising benefits from the new protocol are minimal. Sorry, changing threads makes referring back to earlier posts more difficult - are these results with the router connected to the test socket?
David
David
scootie
Grafter
Posts: 4,799
Registered: 03-11-2007

Re: Bits/Per tone graph - Does it look right?

spraxyt u may be on to somthing there.
if keep refreshing the bit tone graph till sum of my downstream tones turn green and then check the bit swap graph it ties in nicely with a bitswaping happing at that moment. strange thoe that they would program this in to the bit tone graph thoe as soon as you refesh again it resets its self  so dosent really tell you much.
As for upstream bit swaps ive never seen any  on max preminum or adsl2. i get a whole lot of downstream swaps thoe but no upstream as you can see below
ComplexP
Grafter
Posts: 98
Registered: 02-10-2009

Re: Bits/Per tone graph - Does it look right?

Quote from: spraxyt
Light green tones show where bit-swap has occurred since (I think) sampling started. This marking highlights tones/frequencies which are affected by interference though I think without specialist kit trying to identify the cause is a matter of trial and error (and it might well be external anyway).
I was surprised to see significant effect on upstream tones. It's very rare to see an upstream bit-swap on my plot though I'm still on IP stream max. ADSL2+ not due until next year.
As far as (lack of) improvement in downstream sync speed with ADSL2, since tones above 160 contribute little to throughput it is not really surprising benefits from the new protocol are minimal. Sorry, changing threads makes referring back to earlier posts more difficult - are these results with the router connected to the test socket?
David

Hi David
Thanks for the info. The filter is indeed currently plugged directly into the test socket and has been for quite a while now since I use a noise cancelling faceplate style but I have no extensions anyway so I don't think that internal wiring could be causing any problems.
I just refreshed my bits/tone graph and those light green lines in the upstream area have disappeared entirely. I'm coming to the conclusion that my connection is simply as good as it's going to get and the speedtest.bt tool is just plain wrong Sad
I've left a ticket open with PN to see if there's anything that can be found to explain things but haven't gotten much more than the stock responses so far.
ComplexP
James
Grafter
Posts: 21,036
Registered: 04-04-2007

Re:Bits/Per tone graph - Does it look right?

Hi,
Have you tried monitoring your graphs whilst using a different filter to see if you notice any obvious improvement?
ComplexP
Grafter
Posts: 98
Registered: 02-10-2009

Re:Bits/Per tone graph - Does it look right?

I do have a 'normal' filter that I could plug directly into the test socket. I could use that to see if there's any obvious differences. I'll give it a shot and let you know.
dick:quote