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[konrado5]

I've noticed there are always short peaks at my downstream SNR margin. There is no day without peaks. It happens once per few hours. Example is on the attached graph nearby the end.

What can be cause of it? Is it short absence of REIN or rather any little line fault eg. poor joint somewhere? SNR margin for upstream seems perfect and on this forum I've read poor joints cause considerable fluctuations on upstream.

Best regards
konrado5

[burakkucat]

I have looked at the right-hand end of your SNRM graph and can see nothing that is out of the ordinary. All of the small peaks and dips, both DS & US, are well within the expected range for minor, transient variations. I appreciate that your graph is for a two hour period but please take a look at my typical SNRM graph for a one hour period, below. There is no cause for concern . . . whichever one of the graphs is considered, yours or mine.

It is sudden, erratic changes in the SNRM, with wild swings, in both ways, that can be an indicator of a defective joint. Note the words "can be" . . . Such a suspicion is augmented if audible noise is noticeable when the telephone is in use. 

[konrado5]

All of the small peaks and dips, both DS & US, are well within the expected range for minor, transient variations.

Once per few hours two times very short raisements eg. from 0.7 dB to 1.2 dB are normal? I know peaks and dips 0.7-0.8 dB are normal. I know it is normal at night SNR margin raised from 0.3 dB to 0.8 dB and it keeps many hours. I doubt about very short and regular raisements about 0.6 dB.

Best regards
konrado5

[konrado5]

It is sudden, erratic changes in the SNRM, with wild swings, in both ways, that can be an indicator of a defective joint.

I don't understand? Do you say about my or rather your graph?

Best regards
konrado5

[kitz]

I think I may have just wasted the past year trying to explain to you what SNR is and how it works. 

This is something Ive gone over time and time and time again with you,  and you insist you understood. 
But If you had read what Ive said in the past.... or if you even in anyway shape or form took on-board what has been explained to you many many times, then you would not have even bothered asking the question. 

If you read the main site, you will see that it repeatedly states that fluctuations in SNRm is normal.  EVERY single line will show fluctuations.

I didnt know whether to laugh or cry or go smash my head against a brick wall when I saw you ask this question again.


There is NOTHING wrong with your SNRm in those graphs...  in fact its what would be called rock steady.   Fluctuations of up to 3dB are considered NORMAL - this is why adsl2+ needs an SNRm of 3dB to work.  Even 6dB fluctuations on some longer lines are considered normal.


THERE IS NOTHING WRONG WITH YOUR SNRM - in fact its perfect.   

[burakkucat]

No, I am not referring to either of our graphs. I consider them both to be normal.

I am thinking about what Kitz experienced, as shown in this post or what renluop has recently noticed, as reported in this thread.

[konrado5]

I apologize if my question seemed to be questions about typical fluctuations. I know fluctuations are normal. I question about one type of fluctuations. 0.7-1.2-0.7-1.2 during few minutes once per few hours. I don't see it on burakkucat graph.

Thank you very much for your help
konrado5

[kitz]

It is sudden, erratic changes in the SNRM, with wild swings, in both ways, that can be an indicator of a defective joint.

I don't understand? Do you say about my or rather your graph?

Best regards
konrado5

Neither - b*cat said both yours and his graphs where good. 

Below is a sample of a graph showing a bad joint - see how it swings between 0dB and 18dB  - that is what we call a spike.