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[jeffbb]

Hi

I am not sure what you are trying to achieve . You are connected at the maximum you can be ,if as you say you are capped to 8 megs . The SNR margin spikes you are talking about are not a  problem , they do not indicate noise . The higher the spike the more margin you have . Because you are artificially capped then you will have tones available for data but will not be fully populated as you are at the max connection speed possible . So the SNR margin is approaching or even equal to the SNR.

If you imagine the SNR margin graph upside down then that would be the approximate plot for noise .

Regards Jeff

edit
quote : if I do that then my Downstream Bitrate will drop

you cannot improve your bit rate above the number required to give you your capped synch rate .

[solorize]

Thanks Jeff for your explanation / informaiton.


Just had a look this morning and Ouch! where have all my tones gone!
Now I only have 268 available.

Am I correct in thinking if the tones above 320 are made up with lots of
noise then the router just does not display them as there are of no
use? Therefore in my screenshot they are not displayed as there was
noise on these over night?

Sorry for all the questions, I just want to get a fuller understanding 


I have now tweaked up my SNRM to as high as I can get it as my router
had reset over night =( and I want to have a stable connection. So would
rather sacrifice some speed to keep the router from resetting.

[jeffbb]

Hi
quote:
 Am I correct in thinking if the tones above 320 are made up with lots of
noise then the router just does not display them as there are of no
use? Therefore in my screenshot they are not displayed as there was
noise on these over night?


Because you have increased your target SNR margin you have lost some tones , the SNR on those Higher frequencies is not sufficient to be populated and maintain the target SNR margin you have set .

Remember each 3db SNR margin above 6db can cost anything up to 1200Kbps in synch speed .

What makes you think your line is unstable . It was synchronising at the max for your capped line  set up .

If you want to investigate your line I would Reset your tweak to the default  target .Let it settle for a day
then run routerstats  for a couple of days this will show  the SNR /SNR margin trends + all the stats over your monitoring time .

Then we can see how your line is behaving .

Regards Jeff

[solorize]

Hi Jeff,


Thanks again for your reply and explanation for the loss of tones.
I was wrongly thinking that noise had knocked out those frequencies.

I will take your advice and put my SNRM back to the default and run
RouterStats and will post the results up.

FYI.
My line had been ok for over a year with it on "G.992.3 ADSL2 Annex A"
with my previous provider "Be*"(8meg connection). But since I have switched
provider to "O2" (as it was a lot cheaper) and am now on G.992.5 ADSL2+ Annex A,
I have started to have the router reset every now and again.

I run a webserver and a shoutcast server from my home so need to have
my connection up and running as near to 100% as I can.


Regards,

Mark

[jeffbb]

Hi

quote But since I have switched
provider to "O2" (as it was a lot cheaper) and am now on G.992.5 ADSL2+ Annex A,
I have started to have the router reset every now and again.

Sometimes you get what you pay for .

How often do you lose synch . No line will stay up for ever . Are you losing Synch or connection to o2 ?

Anyway when you run RS we will have a better idea about your line .

btw what router are you using ?

Regards Jeff

[HPsauce]

My line had been ok for over a year with it on "G.992.3 ADSL2 Annex A"
with my previous provider "Be*"(8meg connection). But since I have switched
provider to "O2" (as it was a lot cheaper) and am now on G.992.5 ADSL2+ Annex A,

That's really quite strange as you would be connected to exactly the same exchange equipment.
Could your BeBox have been faulty; presumably you changed to the O2-supplied router?

[solorize]

Jeff;

My Router is a "Speedtouch 780"


DTM Tool, tells me that I have had 2 resets since
it has been rebooted the other day. Therefore I guess
I am losing Sysnc? not connection.

Once I have run RouterStats, will I need to post up the
contents of my routerstats.txt log file? or is there
another file I will need to look at?


HPSauce;

I am still using my previous BeBox which is the
"Speedtouch 780", as this allows me to run DMT Tool,
where the O2wireless speedtoch 585 wont allow it to
run.

I did set it up the O2 router and had it running for a day when I
1st got it, but thought it would be better to just use the  BeBox
as it was a higher spec' router. Plus I could see exactly what was
going on with my connection.

I know I could use RouterStats, but it does not show the bitloading
graph, as does the DMT TOOL.

[HPsauce]

Jeff;I am still using my previous BeBox

It should be sent back (freepost address) at end of contract, unless you pay for it (£50 or £100 depending when your contract started I think) as it's not "given" to you, just loaned.

[jeffbb]

Hi
quote I know I could use RouterStats, but it does not show the bitloading
graph, as does the DMT TOOL.

If your router is compatible with the full RS as opposed to the RS lite then You would have BETTER Bit loading info  graphed in real time .

quote  Once I have run RouterStats, will I need to post up the
contents of my routerstats.txt log file? or is there
another file I will need to look at?

No you should just post the SNR margin graph .

Regards Jeff

[kitz]

You mean the pilot tone - on adsl1 tone 64 is reserved for the downstream pilot tone by BTw.   
But I too have noticed that since going on adsl2+ with an LLU provider (Be), that the pilot tone does on the odd occasion use different channels, but have never been able to ascertain why this happens.

Im not certain but Im assuming that this must be something that is determined by their MSANs...  and no there is no way which Im aware of that it can be pre-determined by the router.

I wouldnt worry about it too much - at the very very most (and very highly unlikely) it will be costing you 40kbps MAXIMUM.

After having a very quick look at your bit loading.. more likely in the region of about 4/8 kbps even if you could shift it.

TBH it looks like to me its actually at about the best frequency for your line anyhow.  Move it any higher and youd loose a tiny bit of more speed.   Move it any lower and those frequencies could become unstable.  The pilot tone for very obvious reasons needs to be in a range where it is going to get a decent signal.

[solorize]

HPsauce;

Be will let you keep the BeBox for a sum of £35, which is what I
will be doing. https://help.bethere.co.uk/help/support/bebox_return

Jeff;

My Speedtouch 780 is not fully compatable with RS, therefore I
can't see Bit loading info.

My O2 router is a Speedtouch 585 which I think is compatable,
thefore I may try it out again this weekend and see what happens.

I have set to schedule the option to "ALWAYS" to capture the SNR margin graph
is that the correct way to save the graph? as it just captures one screen
at a time and I am now building up a set of .jpg files.

Kitz;

Thanks for your info and explanation.

[HPsauce]

Be will let you keep the BeBox for a sum of £35

That's a "fairer" price, it was £100 when I joined them.
Not that I use it - lives in it's original box - I run a DG834GT. 

[kitz]

>> My line had been ok for over a year with it on "G.992.3 ADSL2 Annex A"

Both Be + O2 use ADSL 2+ G.992.5.  In fact as already mentioned, you will be connected to exactly the same MSAN at the exchange, as O2 use Be's equipment.

Be doesnt use G.992.3. Are you sure thats what your router displayed? 
However it is possible to over-ride the adsl standard (in a down-wards direction) using ST routers.. and I wonder perhaps if this is what you had been unintentionally doing if you are sure it was adsl2.  ADSL2 will limit your speeds to a max of 12Mbps as it shuts off tones after 255. 

Do you know what your target SNRM is set with at O2?  Im wondering if perhaps with Be you had a slightly higher target SNRM than what you do now, which may have been giving you slightly more stability.

Routerstats is the way to go really to see how much your SNRM varies throughout the day/week.. in order to be able to judge the best target SNRM.

You should be able to run RS + DMT tool -  I do if needed.

[solorize]

OK, after a bit of messing about lastnight I have switched over
my BeBox to my O2wireless box.

Which has now allowed me to use RouterStats, and shows the bit loading
etc. I have now started loggin stats, so I will let it run a couple of
days then post up details.

Kitz;

I had asked Be to switch me to G992.3 to see if that would make my line
more stable, which they did, and this did improve my drop-outs / resets.
I had been advised by someone else on the BE forum that it was worth a try
to get my line more stable.

My default SNRM with be was 6dB, but I had also pushed it up (using DMT TOOL)
up to the maximum SNRM it would allow, as I wanted to get the line as stable
as possible, and would rather sacrifice a bit of download speed to get that.


FYI.
Over the past couple of years we did keep getting power cuts due to dodgy
cabling in the street. Which has now been re-laid so that may have had
something to do with the phone line and affecting my connection. Thus why
I had to push up the SNRM to try to avoid the problems.

I am hoping now that with the O2 router I will get less drop-outs, I will just
have to wait and see.

I have attached two screen captures from RouterStats today just to show you what
it looks like.

Bits / Tone Graph:




Bitswapping graph:





Mark

[orainsear]

My default SNRM with be was 6dB, but I had also pushed it up (using DMT TOOL)
up to the maximum SNRM it would allow, as I wanted to get the line as stable
as possible, and would rather sacrifice a bit of download speed to get that.

You are most likely already aware of this; BE can set the default SNR margin for you if you raise a ticket.