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Author Topic: Curious paper  (Read 15463 times)

konrado5

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les-70

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Re: Curious paper
« Reply #1 on: April 17, 2014, 08:08:04 PM »

  Thanks for pointing it out.  It is an interesting paper revealing some examples of the variability in lines and discussing some of the issues and possible central diagnostics.  I have saved it for future study.
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konrado5

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Re: Curious paper
« Reply #2 on: April 17, 2014, 08:17:51 PM »

It probably explains also why attenuation measurement is slightly depended on power output etc. despire real attenuation is static.
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burakkucat

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Re: Curious paper
« Reply #3 on: April 18, 2014, 12:34:13 AM »

Thank you for the link. I, too, have downloaded a copy of the paper . . .  :)
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konrado5

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Re: Curious paper
« Reply #4 on: April 18, 2014, 01:05:18 AM »

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burakkucat

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Re: Curious paper
« Reply #5 on: April 18, 2014, 01:23:35 AM »

burakkucat: could you reply?
http://forum.kitz.co.uk/index.php?topic=13847.0
http://forum.kitz.co.uk/index.php?topic=13838.0

Now you are hijacking your own thread!  :wall:

I have previously explained to you, in a PM, that I read all the posts that are made to all threads in this forum. I have also explained that I will post to any thread . . . when there is something that I feel I can add to the topic being discussed.

To answer your question "burakkucat: could you reply?", there is absolutely nothing that I can add to either of your two threads that has not already been said elsewhere.

Quite honestly, Eric (roseway) has summed it up precisely in his reply:

Quote
You aren't going to get an answer to that question here. The only answer anyone here can give is "We don't know". The 410-477 gap isn't something we see in the UK, so it may be something specific in Poland, or it may be something which is specific to your ISP. However many times you ask this question, the answer will remain the same: we don't know.
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GigabitEthernet

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Re: Curious paper
« Reply #6 on: April 18, 2014, 12:18:07 PM »

burakkucat: could you reply?
http://forum.kitz.co.uk/index.php?topic=13847.0
http://forum.kitz.co.uk/index.php?topic=13838.0

Now you are hijacking your own thread!  :wall:

I have previously explained to you, in a PM, that I read all the posts that are made to all threads in this forum. I have also explained that I will post to any thread . . . when there is something that I feel I can add to the topic being discussed.

To answer your question "burakkucat: could you reply?", there is absolutely nothing that I can add to either of your two threads that has not already been said elsewhere.

Quite honestly, Eric (roseway) has summed it up precisely in his reply:

Quote
You aren't going to get an answer to that question here. The only answer anyone here can give is "We don't know". The 410-477 gap isn't something we see in the UK, so it may be something specific in Poland, or it may be something which is specific to your ISP. However many times you ask this question, the answer will remain the same: we don't know.

100% this.

konrado5, accept that there's nothing you can do and move on, please.
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konrado5

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Re: Curious paper
« Reply #7 on: April 18, 2014, 03:46:28 PM »

burakkucat:
Quote from: roseway
The 410-477 gap isn't something we see in the UK, so it may be something specific in Poland, or it may be something which is specific to your ISP.
I know also it is not something specific in Poland. Polish engineer confirmed it is not normal. I'd like to explain why it is not something specific for ADSL in genera. If you don't see it in UK, you know it is not specific for ADSL2+. I'd like to explaining why. lI'd like to know how to explain it is not normal. I'd like to persuade my ISP to search for cause of this. Perhaps my ISP mounted 160m band notch-filter and I want my ISP removed this filter or explained me reason for mounting.
« Last Edit: April 18, 2014, 03:59:19 PM by konrado5 »
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roseway

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Re: Curious paper
« Reply #8 on: April 18, 2014, 04:22:47 PM »

We know your reasons.
We don't know the answer.
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konrado5

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Re: Curious paper
« Reply #9 on: April 18, 2014, 04:35:51 PM »

Is it following reply a good reply? It is normal: higher synchronization=slighty higher attenuation=slighty higher interference capacity. On my SNR graph 410-477 tones are significantly more interferenced and tones 478-511 are much small interferenced. It is not normal
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roseway

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Re: Curious paper
« Reply #10 on: April 18, 2014, 04:57:51 PM »

No, it's not normal. We don't know why it happens.
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  Eric

konrado5

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Re: Curious paper
« Reply #11 on: April 18, 2014, 04:59:12 PM »

No, it's not normal. We don't know why it happens.
It implicates I formulated my question wrongly. I question about why it is not normal (not why it happens). My english is not so good.
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kitz

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Re: Curious paper
« Reply #12 on: April 18, 2014, 05:10:43 PM »

I didn't want to respond to this thread because I have nothing new to add that I haven't already covered.

konrado I think perhaps you are getting confused as to what is normal.

From memory your graph displayed some dips that across the adsl spectrum would not be considered normal ie there were gaps.

It doesnt display the tail off you would normally expect to see for long lines - thats because your line isnt particularly long.   To me it displays signs of some sort of interference.  Now I refuse to discuss that again, because over the past few months, several people have advised you what those possible causes could be. You have dismissed every possible cause - and there have been numerous suggestions made. You dismissed local radio hams, but how do you know there isnt one for sure..  Ive seen a case where a taxi CB radio cause similar symptoms to someones line.   My own line on adsl2+ had a notch cut out that was supposedly down to maritime frequencies.   
 

What I think you are missing the point on is that because of the way adsl works it is pretty normal for most lines to see some tones that are affected by something or other.   In fact its far more common to see some tones missing or dipped, its rare that there is a straight line decline without some sort of interference or other.  It only usually happens on the very short and good lines.  Even just normal background noise mush causes peaks and troughs. 

Unless you can find a specific cause then you are out of luck...  I think even a qualified REIN engineer would tear his hair out trying to diagnose your line & symptoms..  there's too much background noise about irrelevant concerns.   We have tried to explain to you many many times all we know and I refuse to keep going round in circles.

If your ISP has notched certain tones then there would be a good reason for it and you wont be able to get it removed. I had a notch at tones 476 - 499 were no bits were loaded.  I had to live with it and just be thankful that I had a good line with good performance and a good internet connection.

B*cat has repeatedly shown you his graphs, and how they arent a normal straight line, but the behaviour was normal and it was as good as he is going to get.

We have repeatedly tried to assist you, but you are getting hung up on the wrong aspect of normal.  This is why now we feel that we cant help you any further.   We cant give you an answer to something when we dont know what exactly is causing it.    :(
« Last Edit: April 18, 2014, 05:12:47 PM by kitz »
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c6em

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Re: Curious paper
« Reply #13 on: April 18, 2014, 05:18:54 PM »

OK,

There will indeed be people who know the answers.
These people work for the DSLAM manufacturers and will be prohibited by their contracts of employment from making any comments about their work on any public forum, or indeed to any person outside the company.
You will not find these sort of answers on the web.
Indeed if you read my contract of employment literally when I worked full time it was doubtful whether I could even tell people who I worked for let alone what I did or what the firm made!
So all of this tech info is confidential propriety information secret to the suppliers.

In the UK the DSLAM manufacturers supply to BT the network operator and BT supply the resulting product to the ISP. I doubt even BT know how it works in great depth.  They will supply parameters to the DSLAM manufacturers which they require to be met and the DSLAM makers/designers will meet that spec.  How they do it they certainly are not going to share with anyone else.

As regards your ISP,
They are not tech experts - they will not know the answers.  They buy in the product and sell it on to you and me.
In the world of bespoke low volume high cost industrial sales yes, the sales people know about the product and are expected to be able to talk technical details to their customers.   Invariably both sides will be educated to university degree plus level.
 
But in the field of mass market consumer sales like this where your customer base may number in the millions of subscribers the world is different. 
It is a case of here is the product, we are not going to change it just for you, the world does not revolve around what one subscriber wants, we have no one able to discuss it with you, you are just one of millions of subscribers, and we really do not care if you go and buy it from someone else.
That is how mass market consumer products work and that is why they are cheap.

Contrary to expectations on forums everywhere on all subjects we as consumers do not have some right to know how something works or why some setting is set as it is.

Digressing briefly on onto the subject of attenuation.
I have two different routers of slightly different make from the same manufacturer, The line Hlog curve reported by one is different from the Hlog reported by the other as is the overall quoted line attenuation figure by 2dB. The line does not change and I can swap the routers over back and fro and the reported attenuation changes with the routers.
This is not the line changing its characteristics, it the the calculation/measuring methods used by the different routers internal firmware that is resulting in different attenuation's being reported.

Finally, I do not frequent forums where my own sector of expertise is on rare occasions discussed. It is a total waste of my time.  Trying to explain to someone how something is and why it is and the compromises necessary both theoretical and manufacturing to arrive at the best overall solution when that person does not already have a technical background in the subject is impossible.  Much as say someone trying to explain to me about postgraduate level particle physics!

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konrado5

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Re: Curious paper
« Reply #14 on: April 18, 2014, 05:42:53 PM »

kitz: I thought burakkucat excluded external interferences becaufe of my QLN graph. Anomalous region is lowered on QLN graph (and not raised). Moreover, I've still didn't get reply if deliberated DSLAM setting excluded because of:
Quote from: kitz
However I notice a slight dip in snr both before and after which could point to radio/EMI interference being the cause.
Moreover, SNR on unused tones is negative. Is it possible with DSLAM delibareted settings? Moreover, sometimes tones 410-415 are used, sometimes not, sometimes tone 478 is used, sometimes not.

Thank you very much for your time
konrado5
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