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Repeated intermittent failures

Posts: 2
Registered: ‎08-09-2016

Repeated intermittent failures

I have been experiencing a problem with my broadband service for quite a few months, where the connection drops, apparently spontaneously, and then does not return for several hours. Typically, it fails in the mid-evening, and is out for a couple of hours; sometimes, it does not return until the early hours of the following morning.


As a former IT professional, I know my way around the equipment and testing procedures to some degree, and these are some of the things I have done (in roughly the same sequence) to try and address the outage:

  • Establish that the problem is not a local networking issue
  • Disconnect telephony equipment (the telephone line continues to work fine during these ADSL outages)
  • Manually restart the ADSL connection from the router admin page (the main router I use is a Draytek Vigor2760)
  • Reboot the router from software
  • Power-cycle the router
  • Swap out the router-to-wallport cable
  • Replace microfilters (in past); now I use filtered faceplaces, of which I hold a couple of spares
  • Substitute an alternative router

Despite the fact that I know that these actions are not likely to make a difference, I have nonetheless followed them precisely during the first three or four regular outages, invariably with the same result: none of them result in the broadband service returning. 


I adopted a new policy of leaving well alone and simply monitoring, and waiting for the service to return, which it does without any intervention, suggesting that it's not as a result of anything anyone is doing inside the building.

This is becoming increasingly frustrating, though. I often work in the evenings, and my access to the Internet is an essential part of that. I cannot imagine that this can be anything other than a failure at the line or exchange.


From monitoring the router during the outages, it appears that what happens is that it repeatedly attempts to reconnect, and usually gets as far as negotiating some kind of link (it gets as far as reporting up/downstream link speeds), but seems to fail at the point of logging in to establish the next layer.

I am reluctant to go through the usual "report a problem" process every time, because I think I have adequately covered those bases, and I am wondering - especially given that there appears to be others on here who experience the same difficulty - whether I am being affected by a more general problem.

Here's a dump of the ADSL status page when the link is up and working:

> adsl status
  --------------------------- ATU-R Info (hw: annex A, f/w: annex A) -----------
   Running Mode            : ADSL2 Annex A       State                : SHOWTIME
   DS Actual Rate          :  6963000 bps   US Actual Rate       :  1020000 bps
   DS Attainable Rate      :  6856000 bps   US Attainable Rate   :  1020000 bps
   DS Path Mode            :  Interleave    US Path Mode         :  Interleave 
   DS Interleave Depth     :       16       US Interleave Depth  :        4 
   NE Current Attenuation  :       45 dB    Cur SNR Margin       :        5  dB
   DS actual PSD           :    19. 7 dB    US actual PSD        :    12. 5  dB
   NE Rcvd Cells           : 19791230       NE Xmitted Cells     :  1066032
   NE CRC Count            :      180       FE CRC Count         :        0
   NE ES Count             :      145       FE  ES Count         :        0
   Xdsl Reset Times        :        0       Xdsl Link  Times     :       81
   ITU Version[0]          : b5004946       ITU Version[1]       : 544e0000
   ADSL Firmware Version   : 05-07-01-08-00-01 
   Power Management Mode   : DSL_G997_PMS_L0 
   Test Mode               : DISABLE 
  -------------------------------- ATU-C Info ---------------------------------
   Far Current Attenuation :       26 dB    Far SNR Margin       :        5  dB
   CO ITU Version[0]       : b5004946       CO ITU Version[1]    : 544e71c8

So we're picking up a small number of near-end CRC errors, but everything else looks fairly reasonable.

Are there any more tweaks I can do to improve stability, or what's the next step to take?

Plusnet Help Team
Plusnet Help Team
Posts: 13,817
Thanks: 271
Fixes: 78
Registered: ‎27-04-2007

Re: Repeated intermittent failures

Hi there,


Sorry to see you've had issues and thanks a lot for trying what you can to eliminate causes on your side.


have you tried connecting to the test socket (if applicable) to rule out any internal wiring issues?



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 Adam Walker
 Plusnet Help Team
Posts: 2
Registered: ‎08-09-2016

Re: Repeated intermittent failures

Aha, yes, I forgot to mention that one, didn't I? Smiley That was, in fact, the first thing I did. In fact, since I was not 100% sure that the 3 microfilters I have were sound, I tested it with each of them, as well as two brand-new Clarity Pro LJ4F ADSL/VDSL faceplates, both of which have gone on to do sterling service elsewhere. We have no telephone extension cabling to cause issues, as all telephony is done over DECT.

Interestingly, the problem appeared only to surface following the arrival of fibre ADSL in our area, and it did occur to me to wonder if those things were related. One option might be to switch to fibre, though I am reluctant to do that if it does not result in an improvement: for most of the work I do, my bandwidth requirements are usually modest.