SNR Reset and long dodgy rural lines

[#1]

I've attached what I can see.
In my opinion, your line is erroring, you may be able to see these as CRC Errors on your line stats? An update on your router stats would be helpful, if at all possible?
Your sync rate is very, very low, potentially caused by the high rate of errors and high SNR alongside with the slight increase of your Line Attenuation.
Your line is erroring every 45 seconds and from time to time, drops sync to the exchange which isn't good. On Monday, for example, your connection dropped 8 times at least that the DLM has recorded, for what reason? I'm unsure, something we need to look at though.
Your Line Quality is red as a result of the above which is a tell tale sign of a poor line. The move from 20CN to 21CN *may* help but if it's a cabling issue you may see no improvement. For that reason, I would certainly ensure there is nothing internally that could be causing the fault, if all is clear internally, I wouldn't hesitate in getting a fault raised.

[#2]

Quote

All extensions are wired as "plug ins" to this socket, just two which is to a sky box and a phone handset, both of which are filtered at the end of the extensions as well as having a pigtail filter plugged into the socket.

@Uncle_Meat - This is quite possibly the source of the problem, however, can you confirm the wiring looks something like this?

                           / double phone adaptor - extension cables running to micro-filters - phone handset / Sky box
(1) Socket - micro-filter -
                           \ ADSL modem/router
Or this - 
                                   / cable running to micro-filter connected to phone handset and ADSL modem router
(2) Socket - double phone adaptor - 
                                   \ cable running to micro-filter connected to Sky box

If the set up is like (1) then you have double filtering, and you should just set it up like (2) instead.
If there is some other configuration, can you do a diagram or even attach photo(s) of your set up so we can advise?

[#3]

Cheers for that Chris.  As before, I'll get the heavy stuff out on the internal wiring first. Deffo a line fault somewhere, just need to eliminate internal wiring before I get BTO and their chargable natures onto the case..
Jaggies..    My current wiring is essentially 1 at the moment, however this was to try and test for any potential additional noise on the line.  My landlord has recently (before this problem started happening, to be fair) bought a plasma TV. Now, I'm aware that plasma TVs can play havoc with by radiating RF interference, but saying that I had not noticed any via my HF sets, but just to be sure I tried double-filtering, judging that the filters will be acting essentially as low pass filters along the transmission (extension) line.

Previous to all this testing and playing around, back when things were working properly, it was wired up as

                                 /Double phone adaptor running to sky box and telephone
Socket -> Filter ->  --
                                 \ Router

[#4]

Quote from: Uncle_Meat

Previous to all this testing and playing around, back when things were working properly, it was wired up as                                   /Double phone adaptor running to sky box and telephone Socket -> Filter ->  --                                   \ Router

I presume that the "socket" above is the MASTER socket?
How practical is it to return to this configuration until we can "see the wood for the trees"?  This puts the router in the ideal position - next to the master socket - and is the correct foundation from which to get BTOR to address any external issues if there are any.  Once they have been resolved, you can revisit your preferred internal arrangements.
If you need Ethernet / WiFi closer to you than placing the router at the master socket permits, you could consider utilisation of a pair of Ethernet over Power adaptors.  For example I use a Devolo 200 WiFi pair which work very well.

[#5]

Yep, no problem.  That is the only socket in the house.  What I assumed was a master socket upstairs was, on investigation, just a plain old junction box.
On my last round of testing, where I was getting no sync, I did try everything disconnected apart from the filter and the router, and still no dice.  I'm almost tempted to, with the curtains closed so no wiremen can see me ;), temporarily disconnect the junction box where the drop comes in and whack it straight into a spare NTE5 I have here, see if that makes a difference.  I'm tempted to temp disconnect at the junction box anyway so I can put a meter across the internal wiring and measure for resistance from junction to socket.

I'm not a big fan of Ethernet over Power adaptors, I've come across many of them which radiate sproggies all over the HF band which, as you can imagine, knackers up my shortwave radios. 

[#6]

Evening all. Again.
At last!  I have a suspect, and that suspect is an iffy joint/crimp somewhere.  I've noticed that my connection quality appears to vary depending upon how much the landline phone is in use, the more phone is off the hook the happier my ADSL appears to be. I noticed a cracking example of this the other day, I had routerstats running on my laptop with a poor but working connection. I went upstairs to chat to my landlord, showed him how to do a quiet line test on the handset and when I came back downstairs my SNR had jumped over 6db to the good in the time I showed him. 
So, tonights task was some monitoring.
See the two graphs attached.
As you can see, I have a steadily declining SNR up to the point where it loses connection altogether.  The second is just a zoomed in version of the second. This is to help clarify my reasoning.
I finally got home again and set routerstats to monitor my connection. As you can see, I had a slow, but working connection from kickoff at 5.30 or so, but with things steadily worsening until I lost things altogether at around 7.15.  Then, it connected again at around 8.20.
So, what happened at 8.20 to perk things up again?  The phone rang..  Bingo!  Current on the line, making a high-resistance joint I thought.
Then, as you can see more clearly on the second graph, things slowly deteriorated again until I lost connection at 11.05.  So, about 5 mins later I crept upstairs and took the phone off the hook for a moment and, Bingo again!  A connection.

I expect this to deteriorate overnight as usual, I'll post another graph if I remember but I think I might have nailed something here, but would I be best reporting this to the line provider or to plusnet?

[#7]

Line provider in the first instance - I would report a noisy line, but don't mention ADSL to them or they'll just try to fob you off back to Plusnet.
Have you done the Quiet Line Test? On a wired handset, dial 17070 and choose option 2 - listen for noise/crackles/pops on the line. If you do this at a time when your ADSL connection has dropped, and if you should hear any noise, get on to your PSTN provider. Don't call them on your landline, as that will clear the fault when they test it.

[#8]

Quiet line test is OK, all the times I've tried it and when I took the phone off hook last night to kick things back into shape, the dialtone was nice and clear with no obvious noise or distortion.
If I was to report it as a noisy line to the provider, I suspect I'll get the "it rings in and out and you can hold a clear conversation" thing, as the act of just using the phone masks the fault.
Anyway, this mornings plot. No telephonic activity so far, and the line is trying gamely to stay up at a whopping sync of 160kbps.
Would a line test from PlusNet reveal anything different from what the line provider would show?

[#9]

I've just run a few checks on your line and we're seeing a very sporadic connection here.
<img src="http://community.plus.net/visualradius/generated/image13994502333273.png"/>
The graph shows a large number of disconnects, on some occasions, the connection doesn't come straight back. From the DLM records, I can see that the quality of your line is ever changing - slowly getting worse. I've run a Copper Line Test which shows everything to be pretty much fine, I think we should be looking at a broadband issue here.
That said, we've got an automated order in place due to complete in the early hours of Monday morning to move you to 21CN, so this will see you be moved from the equipment you're connected at your Local Exchange and onto new, this will rule out a potential exchange issue, to a certain extent.
If you'd like for us to investigate a fault, you can raise on at http://faults.plus.net but I think you'd be best off waiting for the order to complete in the first instance, however, I appreciate that having such poor speeds can be and is very frustrating.

[#10]

Thanks for that Chris. I did think that, if I was to report a fault, that I should wait until that order goes through and see how things behave from there.
The copper test you run, would that "emulate" the same voltage on the line as would taking the phone off hook? As, if so, is there a chance that this might mask a line fault to a certain extent as using the phone seems to do?
As for frustration, I've been digging out some of my old books to read and I'd forgotten just how good Issac Asimov's Foundation series is so it's not all bad.

[#11]

Haha You can't beat a good book, back to basics.
I'm not actually 100% sure on that. The Copper Line Test disconnects the PSTN momentarily and checks for any AC voltages which shouldn't really be there, this is why a lot of the time you will hear/see us asking customer to disconnect equipment from power sockets around the house as they can case a few problems.
The Copper Test also checks for 'Battery Contact/Earthing' this basically checks to ensure that another line/pair isn't causing disruption to your service. The test will also check for any short circuiting, there are a number of different tests that it does, and it will come back showing as a 'Pass' if the tests all pass and/or are within acceptable limitations.

[#12]

Ta for that Chris. Being a curious sort it's good to learn how things work from your side of things.
Anyway. Last night I kept my connection relatively stable by popping up to take the phone off the hook periodically and, as before, like magic my SNR improves dramatically when I do so.
As an aside, I noticed BT are doing some work on my line when I came into work this morning. 6 poles or so down the road and thereon into the E-side pit in town there are temp traffic lights and BT vans lurking with intent.  I know this work is unrelated to my particular issue, but I wonder if I might find myself inadvertently fixed due to them having a good fiddle around.
Here's hoping!  As before, let's see what happens after next Monday.

[#13]

Evening all.  More to the saga.
Well, my ADSL2+ regrade went through sometime on Friday, I came home on Saturday morning to find myself connected on ADSL2+ with a sync of 1400kbps and 13db SNR.  Unfortunately, I was away from Saturday morning until now and I came home to no sync whatsoever.
After rebooting the router a couple of times I eventually got a 288kbps with 4db or so SNR, so back to usual behaviour.  I tried resyncing a few times in ADSL1, then 2 and then 2+ mode to see if owt helped, but no joy.
Right. I asked my landlord if the phone has been working OK for them, and they said they've not had to use it today and possibly never even used it yesterday.
So, with RouterStats running on a 5 second sample, I took the phone off the hook and tried a quiet line test. Listened for a minute or so.  Nice and quiet, no obvious crackles, pops or static.
Anyway, see the attached graph and see if you can guess the exact moment I dialled out..

Another graph there, if it's of any use.
Current router stats.
       
     
      ADSL Link     Downstream     Upstream    
      Connection Speed       288 kbps       763 kbps  
      Line Attenuation       65.5 db       41.0 db  
      Noise Margin        11.3 db       6.6 db        

[#14]

And again!
I woke up early to see my SNR was bouncing along at about 1db at 4am or so this morning, so I rebooted the router, which then gave me 2db and then went and took the phone off hook for a couple of seconds, which then restored things to 12db or so. Again, see graph and see if you can spot it!
Next stop, faults I suppose!  Just putting this here as a reference for whoever picks it up so they can see the various logs and graphs on here.

[#15]

<img src="http://community.plus.net/visualradius/generated/image13999711795944.png"/>
Our Faults Team will be in touch ASAP, generally within 48-72 hours.