ADSL issues

pill

Hi, hoping someone can can share some thoughts on what is causing my ADSL Down Noise Margin SNR being erratic (SNR anywhere between 4db and 14db over a 24 hour period at 3071kbps sync)

Setup:

Sky ER115 router with a 1m cable to a master socket with a bt Mk4 faceplate

BT synergy 5500 also connected to the same socket.

No extensions from this socket.

TP-Link powerline adapter also connected to the router.

Disconnecting the powerline and phone doesn't appear to help - although if I get a phone call on the landline that seems to boost and stabilise the snr for a couple of hours.

I've had openreach out 3 times in the past 6 months and they have found no fault on the line, when they leave everything is fine for a month or so then gradually drops off - I have routerstats logs if that helps.

Thank you.

Neil_Jones

https://kitz.co.uk/adsl/lowSNR.htm - "SNR can vary on an hour to hour basis, not only is it affected by the speed of your connection but there are other things may reduce your SNR. Hot weather can cause a long line to expand. Wet weather on a connection somewhere could cause dampness and deteriorate the signal. Even street lighting and flashing xmas tree lights have been known to affect SNR. Your router or modem can either hear the signal from the exchange or it cant. If it cant "hear", or to put it correctly can't synchronise with the exchange, then your adsl connection is lost and you are said to have "lost sync".

Also see the section "Noise spikes" - you may be surprised.

Change your filter if you haven't done so already.

Heedtheadvice

You are experiencing a variable SNR setting.

Is that affecting your connection such that it is problematic duch as signal loss or speed variations?

As Neil referenced, if the line characteristics vary then the SNR should change to ensure continued sync. That in turn will affect connection speed but is not worth bothering about if insignificant.

If it is significant it suggests an intermittent fault and it would be worth keeping a log of it over time then getting back on to your ISP and making sure that they and Openreach engineers are aware of that and the figures...and do dig you heals in. Just because it is ok at the instance of test is no reason for them not to take it further!!

Jenni_D

You likely have a failing connector on the line somewhere between your property and the exchange, causing a high resistance loop. What you describe is a classic sign of this ... a phone call generates a higher current through the line which temporarily breaks down the high resistance and so stabilises the line for a short while.

Have you tried a Quiet Line Test?

pill

Thank you for all your replies, I haven't tried a quiet line test - will borrow a fixed telephone and try it.

It does impact my connection and I can get several drop offs in the morning (only 1 today however) - my connection is all over the place as you see from the images. Maybe you are right and I need to keep bugging sky/openreach until they can figure out the root cause.

I live approx 2,340m from the exchange and am on an adsl2+ line

JJ_Egan

OR never located the cause of my similar problem .

REIN and sunshine engineers tried .

FTTP fixed the problem .

Heedtheadvice

For comparison at about the same distance to the exchange on ADSL2+ also:

6dB SNR gives 13Mb/s and 1Mb/s upload on rural line (but not overhead)

and it is consistent.

Nearby on overheadline it was like yours very variable. Very weather affected and changing for a spare set of wires from the exchange fixed that for a while.

But as writ above, if available, FTTP will sort it  much better and give better service.

I would suggest working on your ISP and the Openreach engineer (if and when you get a good one) to put in a not fit for purpose report or beyond economical repair (my words) following several costly visits should give you leverage to get a good discount on FTTP.

FTTC  should be a bit better reliability, depending on how far the cabinet is from your property, but for overhead and long distances or old cabling there can still be issues between your and the cabinet's locations.

Laz123

Or you could try changing the channel on the router. Inssider free will tell you which are the strongest. Note, the lower the figure the stronger the signal.

Jenni_D

WiFi channel will have no impact whatsoever on variable downstream SNR. 🙄

pill

I wish that openreach had a FTTC/FTTP offering here - they skipped a couple of cabinets when they were doing FTTC (the joy). Not on the FTTP rollout plans either.

Three keep dropping letters saying that 5G broadband is available, so may give that a try if I continue to struggle with my ADSL line.

WiFi isn't an issue for me, even though the all the 2.4ghz/5ghz channels are crowded.

I reckon this is the cabinet serving me - 550m if i measure distance on google maps.

Heedtheadvice

All the recently installed ones (that I have seen!) are green coloured but that I suppose means nothing!

I would still chase up via ISP and produce the evidence, current and historically.