Old Skool broadband problems ..

Broadband: Old TV signal hit village internet speed for 18 months https://www.bbc.co.uk/news/uk-wales-54239180

18 months though ?!?!

The owner, who does not want to be identified, was "mortified" to find out their old TV was causing the problem, according to Openreach.

Damn right they didn't want to be identified...

18 months doesn't surprise me at all. My experience is that Openreach are incredibly reluctant to check for RF related problems. All too happy to do traditional analogue pair quality tests etc but very, very rarely have I seen anyone consider the RF spectrum that A/VDSL relies on. It's all E-side/D-side swaps, threats of SFI charges, right when tested/it's an adaptive service and it adapted to being [censored], even when you present buzzing radios to them.

Need to get out of the analogue PQ test only mindset and by default start considering the RF environment. Equipping engineers with an ADSL/VDSL frequency aware radio would be a good start.

Equipping engineers with an ADSL/VDSL frequency aware radio would be a good start.

It could be that many carry them already.

Making people understand that not everything that makes a radio buzz affects DSL might help also.

Interesting article. I have an issue with noise on my line dropping the noise margin down from 6db to 2db or less. It's not large enough to cause the line to drop the connection, however does seem household based as it tends to be in mid-evenings and sometimes in the mornings on a weekend. I notice the neighbour also has a very old CRT TV next door and is first in line to the joint box with me second. .

So the only step you might try would be to, at your fuse board, have EVERYTHING switched off apart from the power to your router, and the all other plugs on the same ring disconnected .... then monitor the SNR from your mobile . Cumbersome, but might show if the issue is within your property or not.

‘Guessing’ at probable causes is not worth effort without some equipment to assist in the hunting.

Hunting REIN is a dark art, it requires persistence, determination, and more than a little luck.

After your helpful comments on a similar post on my thread a while back I did try this. I turned off things one by one, and then in the end shut of everything at the consumer unit apart right hand side of the house sockets (making sure everything else was turned off on that ring). Unfortunately didn't appear to be coming from my house (internally at least).

I tried the radio test and do get noise on the 612khz frequency, however unfortunately I also pickup a foreign radio station on this frequency. However, around my house the radio broadcast was making a pulsating noise which reduced as I moved away from my house.

It's interesting because I thought that it was maybe the smart meters. However, the house in question with the CRT is very close to mine with the TV unit on the wall which effectively faces my smart meters, and the area where there is most noise.

I do apologise, I’d forgotten we’d spoken about this before.

Is it possible to have your neighbour unplug the telly for a couple of hours ? Just for testing purposes ?

What your case does nicely demonstrate, is the great difficulty of accurately hunting such things.

I am sure that would be possible as my partner is very friendly with her. Would the noise margin increase immediately after turning the offending device off?

I do notice that when the noise margin drops it doesn't do it instantaneously (like the article seems to suggest their TV did) but drops 0.1-0.2db every 10 seconds or so linearly down to c.2db. (refresh time of the stats page)

I’d suggest taking a ‘screenshot’ of all the router stats when it isn’t happening to start with ... to have baseline as such. Then have the suspect switched on at an agreed time and then watch the stats.

Some sources don’t kick straight in either, they need while ‘warm up’.

If you get a positive result .... low SNR, heavy corrected errors ... turn the suspect off again, see if things stabilise on the stats, then see if you can repeat the issue by switching it back on.

I believe you have said it doesn’t cause you any service affecting problems. More evidence that it might be nigh on impossible to locate.

like the article seems to suggest their TV did

I had read this as the faulty telly in the article was causing loss of sync to those nearby. Prompting my comment of why it took so long to find ... it being a fairly black and white case.

Unfortunately my Now TV Broadband router doesn't show any error information. However, I think my theory has been blown out of the water as the noise margin has gone down to 2.2db from the 6.1db it was at earlier when I posted. I've meandered past her house (being a nosy neighbour) and the TV isn't on .

In reply to a post by gary333:

Unfortunately my Now TV Broadband router doesn't show any error information. However, I think my theory has been blown out of the water as the noise margin has gone down to 2.2db from the 6.1db it was at earlier when I posted. I've meandered past her house (being a nosy neighbour) and the TV isn't on .

Noise has increased, if margin decreases. Of course the noise could be anywhere on the copper between you and the DSLAM. Do you have a guess route of the cable? Any industrial premises? Any schools or shops?

I do indeed have a strong idea of the route to the cabinet which is c.1060m away. Due to the geography it cannot really go any other way and historic Digital Region and BT council planning applications show the majority of the route back to the cabinet. There are no significant business premises in the area. The cable bundle(s) to the street including my address are ex. exchange only lines that have been intercepted to a new FTTC cabinet being underground all the way.

Any "radio ham" aerials around?

Or taxi businesses?

Edited by RobertoS (Tue 22-Sep-20 11:53:38)

Radio hams spend a long time ensuring their equipment is ‘quiet’ Bob, likewise, taxi firms are, in my experience, rank (geddit) outsiders.

In reply to a post by RobertoS:

Any "radio ham" aerials around?

Or taxi businesses?

Don't think any of those people are knocking about - at least no obvious massive aerials. .

Noise Margin has returned back to 6db so I think this is a mystery we might never solve. Luckily line has been up for over 35 days now without any restarts / disconnections and hits 39,999Kbps so I suppose I should count myself lucky and stop being OCD as I'm not in the same poor situation as these guys in Wales .

Edited by gary333 (Tue 22-Sep-20 12:54:04)

In reply to a post by Zarjaz:

I had read this as the faulty telly in the article was causing loss of sync to those nearby. Prompting my comment of why it took so long to find ... it being a fairly black and white case.

It must have been a really old TV then

In reply to a post by Zarjaz:

I’d suggest taking a ‘screenshot’ of all the router stats when it isn’t happening to start with ... to have baseline as such. Then have the suspect switched on at an agreed time and then watch the stats.

Is an overall wider picture of the event not possible by examining the DSLAM logs ?

I'd be looking at the shielding of...well everything really. Shielding and proper grounding / termination of anything electrical or comms related might not deal with the interference, but it might minimise it.

There's always this - https://fishofgold.files.wordpress.com/2014/06/13964...

In reply to a post by broadbandjockey:

In reply to a post by Zarjaz:

I’d suggest taking a ‘screenshot’ of all the router stats when it isn’t happening to start with ... to have baseline as such. Then have the suspect switched on at an agreed time and then watch the stats.

Is an overall wider picture of the event not possible by examining the DSLAM logs ?

Does the Now Broadband router have this ability? It seems very limited in terms of it's logs for example here is alll I can see.

Sep 22 12:55:41 syslog: Lease renewed 3600 ip *.*.*.*
Sep 22 12:55:42 syslog: VCOP agent started.
Sep 22 13:30:46 syslog: Lease renewed 3600 ip *.*.*.*
Sep 22 13:30:46 syslog: Send out NTP request to ntp1.isp.sky.com
Sep 22 13:30:46 syslog: Received NTP Sync Reply from ntp1.isp.sky.com
Sep 22 13:30:46 syslog: System time is up to date
Sep 22 13:30:45 syslog: VCOP agent started.

In reply to a post by camieabz:

I'd be looking at the shielding of...well everything really. Shielding and proper grounding / termination of anything electrical or comms related might not deal with the interference, but it might minimise it.

There's always this - https://fishofgold.files.wordpress.com/2014/06/13964...

Unfortunately (from a fix point of view) 95% of the electrical wiring is brand new (including meter tails, consumer unit, all light fixtures, all sockets). It was all wired by my father who's a spark with my supervision to ensure it meets my OCD standards which includes much better spacing than required and decent kit.

In addition all the network cables and coxial cables are brand new and kept away from power ). The NTE5 is brand new and wired directly from the underground cable.

In reply to a post by broadbandjockey:

In reply to a post by Zarjaz:

I’d suggest taking a ‘screenshot’ of all the router stats when it isn’t happening to start with ... to have baseline as such. Then have the suspect switched on at an agreed time and then watch the stats.

Is an overall wider picture of the event not possible by examining the DSLAM logs ?

Though possible, I doubt the poster has access to such info.

I was talking about BT using the logs as an aid to solve the original problem, to assess the likely spread of the affected punters,

In that case, Openreach, have a few systems that can be used to show its evidence in a location, but not to pinpoint it. That requires good old fashioned legwork.

In reply to a post by Zarjaz:

In that case, Openreach, have a few systems that can be used to show its evidence in a location, but not to pinpoint it. That requires good old fashioned legwork.

Reminds me of a problem I had with ADSL when I lived in a different village many years ago.....

I noticed the SNR dropping from 8dB to 1dB at regular intervals for up to an hour at a time, then returning to perfect levels. The ISP were helpful and checked everything out - no fault found. This drop was being handled so well by the OR adaptive kit at the exchange that the connection never dropped, but of course the speed was lower than it could be.

I went into detective mode over the course of a week……

What could be the source of the interference? Sure enough with a SW radio I could clearly hear the interference (coinciding with the drop in SNR), but where was it coming from? Street lights? No. Neighbours? No. My equipment? No. Over two weeks my net widened, with considerable 'leg work'....

Eventually I went for a long walk and stumbled across a sewage processing plant over two miles from my property and that of any other village property. I noticed the plant machinery ran to roughly the same timing. I returned the next day, armed with my laptop, VPN connected to the live SNR output of the modem, the SW radio and a six pack of beer, and made myself comfortable on the grass by the fence outside the site. With only one can of beer (maybe two / three...) down - Bingo - as soon as the machinery started up, the SNR went down to almost zero and the radio nearly blew my ears off with the noise! When it stopped the SNR went up by at least 6dB.

I contacted the sewage processing company, who to my surprise, were very helpful and quickly setup a site visit. I showed the Engineer my data, both historic and live, and we went inside the plant control room.

I will never forget the look of horror on his face when he discovered that the racks had never been Earthed since installation - there was the fault! Ironically, he even said that they wondered why in the office, their ADSL connection to the plant dropped out when the machinery ran.

A couple of weeks later, the problem went away, for not just me, but everyone in the village (about 500 properties), most of whom were probably unaware.

So the moral of this story? To find interference often requires time, a SW radio and as Zarjaz says 'leg work' (and, perhaps, a six pack of beer....:-))

Mendip.

Edited by deleted (Tue 22-Sep-20 15:34:08)

An excellent and amusing tale about the sewage plant, now the problem has been solved. Certainly not amusing while it was present.

What is does still illustrate is that even where electrical and electronic equipment has many regulations and standards to prevent such problems, we can never rule out human error or subsequent undetected faults in such equipment or preventative measures.

How was the person to know that they where doing anything wrong? How do you know that there is no faulty equipment in your house that is not impacting broadband performance? I am sure you would be similarly mortified if an apparently perfectly good appliance was causing your neighbourhood such problems.

Personally I would invest in a SDR (software defined radio) USB dongle, plug it into your laptop/computer and start monitoring the RF environment if you think you have a problem. They are not expensive, prices starting at 25USD. I personally have one of these

https://www.rtl-sdr.com/buy-rtl-sdr-dvb-t-dongles/

In direct sampling mode it does 500kHz to 24MHz so ideal for VDSL, but you will miss some of the bottom bands of ADSL. There are other dongles that will cover that for you.

It is in effect a very cheap spectrum analyser. I note it would have been cheaper for Openreach to have posted one of these out along with a raspberry Pi to a customer in the village on a none return basis and just collected the stats and analysed remotely than paying for engineers for overnight stays and being out at the crack of dawn.

It is in effect a very cheap spectrum analyser. I note it would have been cheaper for Openreach to have posted one of these out along with a raspberry Pi to a customer in the village on a none return basis and just collected the stats and analysed remotely than paying for engineers for overnight stays and being out at the crack of dawn.

..... and these remotely gathered stats would have pinpointed the exact faulty equipment/culprit ? (sigh)

They would have pinpointed that the problem was RF noise, potentially months earlier to then justify sending a full team out to pin point the dodgy appliance.

My guess is not investigating RF noise earlier is down to the cost factor in doing so. When they sent the expensive team out to look for RF noise they had no idea if this was a problem, it was by Openreach's own admission a last throw of the dice.

In reply to a post by Mendip:

So the moral of this story? To find interference often requires time, a SW radio and as Zarjaz says 'leg work' (and, perhaps, a six pack of beer....:-))

Nope you just need two SDR's with rotating directional antennas and GNSS receivers Admittedly that would put the cost up a bit. Probably still less than sending a team out to walk about looking for it though.

The only leg work needed is for final pinpointing of the dodgy equipment.

In reply to a post by jabuzzard:

In reply to a post by Mendip:

So the moral of this story? To find interference often requires time, a SW radio and as Zarjaz says 'leg work' (and, perhaps, a six pack of beer....:-))

Nope you just need two SDR's with rotating directional antennas and GNSS receivers Admittedly that would put the cost up a bit. Probably still less than sending a team out to walk about looking for it though.

The only leg work needed is for final pinpointing of the dodgy equipment.

(my bold) but that’s the point .... or rather isn’t. Your half arsed guess finds an area, maybe even a building ..... what do you do then, turn the buildings power off, telling the the owner they must vacate ? Since Openreach have no authority, can only advise ... so, with diligence, you find the exact culprit, tell/show the owner the issue and ask that they don’t use/replace. And hope they heed your advice.

In the good old days the Radiocommunications Agency’s RIS Team (and the Post Office/BT equivalents that predated them) would have been asked to have a look see and had the hardware & skills to track this down very quickly. Ofcom may not be so willing to help, but they do still have some form of interference tracing capability. Of course this assumes that someone had asked the question about whether the interferer being an RF source.

Team, what team ?

it was by Openreach's own admission a last throw of the dice.

Where did it say that ?

In reply to a post by jabuzzard:

How was the person to know that they where doing anything wrong? How do you know that there is no faulty equipment in your house that is not impacting broadband performance? I am sure you would be similarly mortified if an apparently perfectly good appliance was causing your neighbourhood such problems.

My post was written light hearted with a very big smiley grin at the end, Seems it went straight over you're head enough for you to get you're panties tangled.

In reply to a post by Zarjaz:

Team, what team ?

it was by Openreach's own admission a last throw of the dice.

Where did it say that ?

On the ISPreview web site there is a quote from a "Michael Jones, Openreach Engineer " which says

As a final resort we decided to bring in a crack squad of engineers from the Chief Engineers Office who where based in other parts of the UK to investigate

So clearly and expensive last throw of the dice.

Ah, so I am supposed to sense which other web sites you have read the same story on ..... I am clearly at fault, I do apologise.