Going back to basics (was help with dsl router)

[#1]

I have started a new thread as I think the old one was a little misleading in its subject.
In an effort to establish some facts, I have gone back to the start and have my router plugged in to the test socket directly (no phone at present, so no filter)  I have previously tried a different modem (the dsl borrowed from plusnet) plugged into master socket and still got line drops but it has only lost synch once since last Thursday, with the noise margin at 15.
Currents stats attached. Speedtest with plusnet speedtester is 3364kbps, profile is set at 4000 at present, so that's about what I'd expect. Noise margin has been set by BT to 15 because of line drops and I want to try and find out what is causing big swings before requesting it be changed again.
Attached is the routerstatslite graph from yesterday, before I moved router to the test socket. The two evening blips weren't actually loss of synch, just that routerstats was unable to log for a short time.
So far today, the noise margin graph has been steady on 15.
The other attachment shows errors from yesterdays router stats. It will be interesting to see what happens this evening, when I would expect the noise margin to fall, but it does seem to vary quite a lot, more than 1/2db, not sure why.
Any other advice/comments on the screenshots would be appreciated.

[#2]

Yuk, as regards the routerstats noise plots, your internal wiring would seem to need sorting!
Let's see what this evenings looks like now you are at the test socket.
(I'll have to re-read your other thread as well).

[#3]

I left routerstats plotting all night and attached is the graph. This is with the router plugged directly into the test socket, without filter/phone. I do need to have the phone working again today, so will move it in a bit (turning power off at router first and leaving for a short time is best, I believe?) Then reconnecting with a rat-tail filter, into the outside part of the master socket.
Support have replied to my open ticket saying that they think the problem is sorted as the line hasn't dropped for three days, but I'm still not totally convinced. It does look like noise is introduced from internal wiring but we had previously tried a different (adsl modem from Plusnet) plugged directly into master socket with no phones attached and still had a couple of line drops. The line hasn't dropped in the last few days though, which may/may not mean that problem has been sorted. One thing, it probably does rule out rain or wind as we had both on Tuesday night.

[#4]

Now plugged in, still to test socket, with corded phone via filter. Router stats now 6368kbs, Noise 15db and attenuation is 31.7.   
I'll put routerstats to monitoring again.

[#5]

The profile has now gone up to 5500, with noise still at 15db after a restart.
I have had to move the router back into study, as daughter and husband need to use that pc and it has no wireless card. I think we have done all we can reasonably do to improve things here... new router, filters and cabling. Maybe whatever the BT engineer did at the exchange did some good as the line hasn't dropped since the 26th Feb.
I am happy with that speed, even though it is a fair bit lower than what we used to get (6500+) as long as it remains stable. I realise from reading other threads that a lot of people would be happy to get that!
Attached are the latest stats. There do seem to be more errors when it is in here but I don't understand those figures, so not sure if they are particularly bad or problematic or if anything can be done to stop them.
@ Jameseh. Do you think it would be a good plan to leave it as is for a few more days, then maybe request that the snr be set to 9db? I suspect 6db might take me full circle and be too low in the evenings again, causing disconnections.

[#6]

Something is definitely not right. Have you still got only a corded phone plugged in? What is the new cabling?
Unfortunately your profile will drop with that sync speed.

[#7]

Morning Chris. I have been tearing my hair out over this but I am hoping we may have had a breakthrough. My husband isn't really interested in computers and listens to my tale of woe over the connection but doesn't really *listen*    I had mentioned the extension sockets (one in kitchen, one in study and one upstairs and commented on bell wire but he said it wasn't connected in the master socket. However yesterday I did query whether that wire was still connected on the extensions and he agreed to look. It was and has now been removed and has made a 3db difference to the noise margin graph on routerstats lite.
I am hoping this means that in the evening when it all started to go madly up and down, that it won't... if you follow. Looking at it right now, after a router restart, it is on 15db, as that is what it is set at by BT.
Now I can only wait and see what happens this evening.
To answer your other question, yes, the corded phone is still plugged in to the filter on the master socket with the cordless one disconnected. The new cabling was a piece about four metres long to the first extension which was the oldest in the house and ran under the carpet (had been here since we moved here, about 26 yrs ago, so just thought it was a good idea to renew it, in case)
This mornings stats attached.

[#8]

That's starting to look better . As long as that new cable was CW1308 standard or better, that should be ok. Fingers crossed for the evening & night stats.

[#9]

Ok    That is looking a lot better overnight. Noise only varied between 15 and 13db, graph attached.
Apart from me switching off to move it, there have been no disconnections since 26th Feb, so another couple of days and things should improve.  Latest on my open ticket was that it needed to be stable for 48+ before they'd request a change.

[#10]

It has now been a week and it has been steady. I have had a reply to my ticket saying Plusnet will now request that the noise margin be dropped to 9db. When this happens will it re-synch automatically or do I need to reboot the router?
The IP profile has been on 5000 but hoping this may go up at little more once the noise margin has been lowered. All in all I am happy with the speed I am now getting and thank goodness, after a lot of testing and trying to locate the problem it does seem as it is has been sorted, thanks to the good advice received here.
I see many more threads with similar problems and would say, heed the advice to check your internal wiring, particularly removing the bell wire from ALL extension sockets.

[#11]

Interesting. I was going to suggest this on another posting last week but I thought that it was an overkill. The reason being is that the extension sockets have no electrical path between the ring wire and the A/B pair. But as soon as the adsl splitter is plugged in then a path is established. Naively I thought there would have been a filter in the splitter stopping high frequencies getting from the ring wire to the A/B pair.

[#12]

I had previously thought that because the bell wire wasn't connected in the master socket that there couldn't be any interference picked up on the internal wiring. However after my initial problem with line dropping was sorted, the noise margin showed big swings and couldn't be lowered until we had found the cause (strangely it hadn't affected my connection prior to the other problem) 
I was actually watching routerstats when my husband removed the bell wire from the extension socket nearest to the master and saw it go up by three db, so it was definitely causing trouble.

[#13]

To bring this up to date, in case anyone is ever searching for similar and comes across it and wonders what happened.
My stats are now as per below. At last router restart synch was 7104, noise margin 12db. It now only varies between 12 and lowest I've seen, 10.2, so that seems ok.
I've had a couple of seemingly random drops, one in early hours of the morning (around 1am) and one midday'ish, neither of which I can attribute to anything in particular, so will just have to see how it goes.
I have asked in an open ticket (28257840)  whether the target noise margin will get lowered automatically in time but the reply wasn't very helpful to say the least, the person just stated that the line estimate for our line is 5mb so 6mb is a good speed. 
I'm not complaining about the speed at all, I am quite happy with throughput of around 5500 most of the day, I was just interested, for furture reference and generally trying to understand the process, in what happens with the noise margin. Before all this started it had always been 6db. This jumped to 15db with the dropped lines and router restarts during testing and has now been put to 12db.
Any comments welcome.

[#14]

The SNRM target is set automatically by BT equipment based on line behaviour.
The default is 6dB but it can go up very quickly. It comes down very very slowly, usually in 3dB steps.
I've seen examples reported (after a serious problem has been fixed) where each 3dB step takes 30 days, others have reported 14 days.
So, sit tight (for months!) and don't meddle, especially don't turn your router off or reboot/resync any more than absolutely necessary.
And if you can be bothered monitor when it changes and report back on the timing.

[#15]

Thanks for that info. I can't quite get my head round which comes first, the chicken or the egg problem.
Which would be likely to happen first, if at all, an snr change or a profile change? I presume the profile wouldn't change further unless it synchs at a higher rate, so unless I restart the router, this wouldn't happen... or am I wrong?
Should I need to reboot on occasion to see a difference, or *should* either change cause the router to restart on it's own. I ask this as when the profile changed a while ago, my router was 'stuck' showing it wasn't synched with the exchange and I had to manually power off and on again to get reconnected. I asked in a ticket but again, the reply wasn't exactly helpful 😞
I'm happy to just leave the router powered on 24/7 but equally if I need to restart periodically for anything to change, I will.
Currently data rate in router is 7104 and noise 12. Speedtests at this time of day show around 5000, a little higher first thing in the morning, which is fine.