S/N Margin
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S/N Margin
16-12-2011 5:53 PM
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Re: S/N Margin
16-12-2011 6:31 PM
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In my case on ADSL2+ the downstream SNRM drops from about 7.8 during the day to sometimes around 4.5 and doesn't cause any problems. Yours is obviously dropping more than that which is probably causing the disconnections. If you have tried the test socket and get the same results you could try re-synching just after the dropping SNR causes a disconnection and then leave the router switched on continuously in the hope that you will "force" a higher range of SNR which will accomodate the lows at the expense of some speed (you shouldn't really have to do that though and it's possible you do have a fault which needs investigating.)
Re: S/N Margin
16-12-2011 7:33 PM
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Quote from: custos I was moved over to ADSL2+ a few weeks ago and on the whole am pleased with it. My upload speed has more than doubled and the download is up a little. There is one problem though which is rather annoying. During the day everything is fine but by late afternoon and evening the download S/N Margin starts to reduce and eventually drops to almost zero. Once it gets below about 2.5 - 3 dB, page loading starts to slow down and eventually as the evening progresses stops altogether. Rebooting the router usually sorts it out although the S/N still remains around only 3dB or just over. By 8 the next morning the S/N is up to around 5.5 - 6dB and everything is then fine until later in the day when the whole process is repeated. It seems to me that the target S/N is a little on the low side but nothing I do seems to make any difference. I have tried rebooting at different times of the day and even leaving the router off all night on one occasion but all to no avail. Any suggestions would be welcome.
I have this, however i have via telnet forced my router to sync with a higher snr level although doing so lowers the downstream connection speed. I have gone from 6mb to 5mb but my snr at present is 7db where it would normally be down at around the 2db mark this time of night. During the day my snr will be over 9db and i have a rock solid connection now so it appears.
Re: S/N Margin
16-12-2011 8:13 PM
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To answer JayG, yes I have tried connecting to the test socket - that makes no difference.
I will see what happens during the next 24 hours and report back.
Cheers all....
Re: S/N Margin
16-12-2011 8:20 PM
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Re: S/N Margin
17-12-2011 8:45 AM
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Quite why it took so long to stabilise I don't know, but I do get the impression that the DLM isn't so eager to ratchet up the SNR target as it was under ADSL.
Re: S/N Margin
17-12-2011 9:40 AM
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dick:quote
Re: S/N Margin
17-12-2011 10:16 AM
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Quote from: custos After the re-boot last evening it is up to 9dB this morning with a reduced connection speed of 6,872.
If you really want a bit more speed, wait until your SNM drops to 7dB and then reboot your router. Assuming your Target SNM is 6dB this should give you a small speed increase. Just don't try this more than once a day otherwise you're likely to trigger DLM to take 'undesirable' actions.
Re: S/N Margin
17-12-2011 4:22 PM
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At any given moment in the universe many things happen. Coincidence is a matter of how close these events are in space, time and relationship.
Opinions expressed in forum posts are those of the poster, others may have different views.
Re: S/N Margin
17-12-2011 11:14 PM
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I had great download speeds (> 7MB), but once evening came the SNR dropped to zero (or even into the minus range) and the only way I could get a usable connection was by rebooting the router. Sometimes I had to do this four or five times an evening.
I raised a problem ticket. I'm not quite sure how it was sorted out in the end (I think they had to do something to my base SNR). I've only had two disconnections in the last eight weeks (one of them manual), and am currently synching at 5.4MB with an SNR of 1-2 db. Not ideal, but better than before.
Re: S/N Margin
23-12-2011 7:41 PM
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Re: S/N Margin
23-12-2011 7:52 PM
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Once it realises it's not stable (either though high error rates or too many loss of sync), it should automatically put it back to 6dB or higher, with an associated drop in sync speed and hopefully better stability.
If that doesn't happen you may be able to get Plusnet to override DLM with a fixed line profile, which will set your target noise margin to say 6dB or 9dB, but I believe it is usually only done as part of the faults process. If DLM doesn't undo its changes automatically, I think it's reasonable to raise a fault with Plusnet.
Re: S/N Margin
23-12-2011 8:21 PM
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Re: S/N Margin
23-12-2011 8:37 PM
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Re: S/N Margin
23-12-2011 10:22 PM
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