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Disconnects/Noise margin problems after dark

ReedRichards
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Registered: ‎14-07-2009

Re: Disconnects/Noise margin problems after dark

Yes, that is something switching on and off.  If it stops switching on ad off overnight that should help to track it down.  Even so, the change in SNR is not too severe; no reason to think your line would not sustain a 6dB target going down to 4dB overnight. 
Anotherone
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Registered: ‎31-08-2007

Re: Disconnects/Noise margin problems after dark

The effect of whatever was switching on/off is only about 1dB. Is this pattern being maintained 24/7?  It's difficult to tell whether such a pattern existed in the graph in reply #12 as it would have been masked by the other events there.
Ongoing plots are needed to make any further deductions.
Palmski
Grafter
Posts: 84
Registered: ‎21-01-2010

Re: Disconnects/Noise margin problems after dark

OK here's the plots from the past few days. Not sure it tells me an awful lot! No drops at all though which is good.
Edit: to add I tried a resync this morning and I'm still stuck on 6655 downstream, how soon would you expect that to change?
Anotherone
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Re: Disconnects/Noise margin problems after dark

Interesting, in that whatever is "switching" appears to cause the Margin to be reduced for much longer periods than not. I've phrased it that way just in case for some strange reason it's not "on" for very long periods and "off" for shorter periods. On Sunday's plot (posted twice!) there strangely seem to be an additional reduction, one about 0930 and another at about 1015. Anyway have a look at the timings of each of the events over the last few days and see if it fits any pattern of any (electrical/electronic/lighting/computer/tv etc) equipment usage.
Other than that the "switching" seems to be causing about a 1dB reduction in margin, and day to night is around a further 1dB reduction in margin.
Palmski
Grafter
Posts: 84
Registered: ‎21-01-2010

Re: Disconnects/Noise margin problems after dark

It is strange. The only thing I can think of which might be coming on at these times could be the Sky boxes calling back. There was no one in the house between 8.30am and 6pm on Tuesday and Wednesday yet still there are some events occurring. It certainly does not tie up with the central heating times, I'll try watching carefully when the dishwasher/washing machine go on and off in the next few days to see if that is in any way related as those are certainly not switched on at regular times. Other than that I am at a bit of a loss.
Nevertheless it is still a vast improvement on where we were before in terms of reliability for which I am very grateful.
Anotherone
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Re: Disconnects/Noise margin problems after dark

If you've got a spare filter, try double filtering the sky boxes.
Palmski
Grafter
Posts: 84
Registered: ‎21-01-2010

Re: Disconnects/Noise margin problems after dark

I'm still stuck on 6655 sync speed after a week of solid connection, when will this get updated? It should be 3-5 days as I understood it. I've just resynced this morning with no change.
ReedRichards
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Re: Disconnects/Noise margin problems after dark

Quote from: ReedRichards
I would have thought the best thing to do now is to leave things alone for a few days to see if everything is stable then, if it is, ask Plusnet to set your line to retrain.   

As you have not asked Plusnet to set your line to retrain, I would expect you will see an improvement after 400 hours of stability and then another improvement 400 hours later.
Palmski
Grafter
Posts: 84
Registered: ‎21-01-2010

Re: Disconnects/Noise margin problems after dark

So roughly a couple of weeks? That's fine, I can wait for that, would rather have the stability than everything up and down as it retrains. Thanks!
ReedRichards
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Re: Disconnects/Noise margin problems after dark

Yes, about 17 days per 3dB change.  I know this because I timed it for my own line (when I was on 20CN).
Oldjim
Resting Legend
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Re: Disconnects/Noise margin problems after dark

If you are lucky.
But if there are seen to be a relatively high number of errors (I know - relatively could mean anything) it doesn't drop at all - like mine
ReedRichards
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Re: Disconnects/Noise margin problems after dark

Yes, my line is very stable with few errors, except when it goes wrong.  So 17 days probably represents the best case. Still, you could wait a few weeks then ask for a retrain if nothing happens.
Anotherone
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Re: Disconnects/Noise margin problems after dark

Quote from: Palmski
I'm still stuck on 6655 sync speed after a week of solid connection, when will this get updated? It should be 3-5 days as I understood it. I've just resynced this morning with no change.

You're getting muddled up there between your sync speed changing and your Profile (BT or Plusnet Current Line speed) updating   Wink
On 21CN your BT Profile will update immediately but the PN one may take 12hrs if BTw systems send your Delta report out promptly.
Anyway it's not a Target Noise Margin change that's required as ReedRichards has incorrectly implied, because your sync speed is banded. I'm sure we can get Plusnet to retrain your line on Monday if you wish.
Palmski
Grafter
Posts: 84
Registered: ‎21-01-2010

Re: Disconnects/Noise margin problems after dark

Well strangely I have just looked and the sync speed has jumped up to 10746 since I last checked, with noise margin between about 11 and 9.5. Confused? Yes, unhappy? No. I'll keep an eye on it in case it drops too low and I start getting disconnections again but it all looks very positive.
Anotherone
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Re: Disconnects/Noise margin problems after dark

Well, well, well! The Exchange DLM has obviously decided that as your dropped connections have ceased and presumably your error rates have dropped to a more acceptable level, that it has unbanded your sync speed. I can't say that I've come across this before, but then I don't read every thread on this board. Mast users I've come across with banded connections have to request the banding be removed! It does all look quite positive as most that have moved from 20CN to 21CN and have enough knowledge about DLM say that it's more aggressive on 21CN, so it must be more happy with your connection Smiley  In time it will drop the Target SNRM as well as long as things look stable enough and the error rate is low enough.
How's it been going with these steps up/down in the SNRM? Any signs of potential causes?
Edit: Forgot to say check your Current Line speed (Login required).
It should match the BT IP profile, run the BT speedtester. If not, someone from the DCT will probably update it for you tomorrow if it hasn't done automatically.