Drop of SNR in working hours

[#1]

I have recently had to work from home a couple of times recently and noticed (sometimes) very slow loading of web pages.
On checking my router I have seen the SNR margin at 1.5, this presumably means lots of errors (you don't want to see my error count, honest) which means that things slow down due to having to re-transmit.
I ran Routerstats and on most (but not all) weekdays there is a drop in SNR margin over about half an hour around 9:30 or 10:00 then it instantly rises back to normal at some time between 17:00 and 18:00
My router is currently showing sync at 8439 Down (with uptime of 35 days), in the evening and weekend the connection performance is good, only during weekdays does it start to run really slow.  I do not want to re-sync to reduce the errors as this will mean slower performance during the evening and weekend when the kids want to surf and game.
I only have a master socket an there is absolutely nothing in my house that operates on a time pattern matching the 'interference'.
Evening / nighttime SNR is currently between 4.5 and 5.5, in the day when this 'interference' occurs it drops to 1.5 to 2 and stays there until whatever time it  decides to suddenly rise:
I'm not sure about how to attach an image but hopefully a routerstats capture will be on here.

[#2]

Dropping again this morning.
I think this is obviously external interference on the line - I assume it is commercial / industrial due to the timing.
I am not located near any industrial area but I guess the line may pass some between here and the exchange.
If something / someone is causing interference on my connection, am I entitled to have this investigated / rectified Free of Charge?

[#3]

Stats from Router @ 9:50 3rd March:
DSL Connection
Link Information
Uptime:35 days, 7:40:52
DSL Type:G.992.5 annex A
Maximum Bandwidth (Up/Down) [kbps/kbps]:19,666 / 6,516
Bandwidth (Up/Down) [kbps/kbps]:928 / 8,439
Data Transferred (Sent/Received) [GB/GB]:173.82 / 21.36
Output Power (Up/Down) [dBm]:12.5 / 20.0
Line Attenuation (Up/Down) [dB]:24.0 / 40.0
SN Margin (Up/Down) [dB]:5.5 / 1.5
Vendor ID (Local/Remote):TMMB / TSTC
Loss of Framing (Local/Remote):0 / 0
Loss of Signal (Local/Remote):2 / 0
Loss of Power (Local/Remote):0 / 0
Loss of Link (Remote):0
Error Seconds (Local/Remote):47 / 0
FEC Errors (Up/Down):435,720 / 0
CRC Errors (Up/Down):60,667,949 / 14,237,140
HEC Errors (Up/Down):NA / 73,376,207

[#4]

Interesting distribution of FEC/HEC errors for the upstream/downstream! Is your line supposed to be on interleaved?

[#5]

Not interleaved.
I get pings to bbc.co.uk at 12-13ms so definitely not interleaved, even now with the reduced performance it's pinging bbc.co.uk at 18-19ms 🙂
I have NEVER trusted all the stats given by a router, look at my Sent Data volume: 173GB!!
Each router shows a different Attenuation for the same line and several give a different sync speed (though only be a small amount) than BT Speed checker.
By the way, my line is on the 'Fixed' SNR margin following a trial some time ago so I always get 6dB target margin and non-interleaved connection (me 1 - DLM 0), the connection has been excellent except for these current anomolies during working hours.
Edit: spelling/typing

[#6]

Those stats suggest your upstream is interleaved!

[#7]

I believe you are correct - I seem to remember that it was for some reason - maybe because it's uncapped?

[#8]

Any PN staff care to comment on this?
I am trying to work from home as my wife is ill but it's taking ages for web pages to load and my 'Log Me In' connection keeps dropping out.
I repeat, the connection is excellent in the evening and at weekends, just next to useless while I'm trying to work.

[#9]

HI walker23,
Is it particular web pages or all webpages? Is 'log me in' a VPN connection? Are you using a wired or wireless connection?
Jojo

[#10]

Hi Jo,
all webpages are slow, the forum pages for example can take 30 seconds or a good few minutes to load, this pretty much returns to normal after abot 6pm when the SNR margin recovers.
Log Me In is an encrypted remote connection, it's not VPN, more a remote desktop via the web.
I'm wireless but I'm pretty certain that's not the issue.
Some webpages time-out and require one or more reloads, there's no noticable pattern to this.
The main question is whether this should be investigated as an 'intermittent line fault' or something like that.
Thanks,
Alastair (walker23)

[#11]

HI Alistair,
Could you try it wired? Have you performed the firmware upgrade for this router?
Jojo

[#12]

OK Jojo,
I'm quite convinced that it isn't a problem with the wireless but I'll give it a go wired to rule it out (once I finf an ethernet cable).
Router firmware
Product Name:TG585 v8
Software Release:8.2.7.8
I assume this is still the latest.
-  Alastair

[#13]

Yes, it is the latest. If you don't mind trying the cable, just so we don't go barking up the wrong tree.
Thanks

[#14]

Not sure how wireless could possibly affect the noise margin!

[#15]

Quote from: jelv

Not sure how wireless could possibly affect...

Agreed but I've now tried on Ethernet (no difference), I have now disabled wireless on the router (just in case that could be causing interference).
I have also tried a silent line test 17070 option 2 on the telephone, there is some background noise but I will need to compare after the router margin picks up again.
Pages are still very slow to load and SNR margin is no different.
I just noticed - on this very page (post reply) half of the icons above the text box are missing (page appears not fully loaded but the windows 7 'spinner' has stopped so I guess I don't get the full page