Had problems since before Xmas with Broadband connected but random no internet. Anyone help p...

[#1]

Hi Rob,

At first I thought that there was not much interest here, but having looked at all of the graphs, I note the following, which needs to be watched daily to see if there is a pattern

1. There is generally variable noise through out the night
2. Some even happened at circa 4:25 which for a brief while lessened the level of noise
3. As dawn approached the noise variability diminishes markedly - somewhat suggesting continental radio interference

To me this suggests that the line has a marked susceptibility to RFI.  That said the connection appears to remain very stable.  I guess that hard question is where do you want to go with this?  Your title reports random disconnections - for the moment I would recommend that you keep the monitoring going.  If there are disconnections, let's examine the graphs and see if you can correlate the times with something happening nearby.  If we can see a repeated event, either being at a similar time or having a similar shape, that will help point towards what to look out for.

@Gandalf 

Can you access metrics on this line's ac balance please?

As for being only able to add one attachment at a time ... well that looks like something else the forum vendors "who are the best in this field" have broken.  At times it seems like there are more bits which have become broken than still work as originally implemented.  @JonoH  @jaread83 can someone raise a defect report please?

[#2]

Hi @joseph1, thanks for getting back to us. Looking at your noise margins overnight there doesn't look to be any points of concern throughout. When looking over your connection this side I can see currently the speed profile on your account looks to be set to 6.4Mbps despite your sync speed being 7.2Mbps. In which case, I've bumped up the profile on the account which looks to  be limiting some of the download speed.

This wouldn't explain the intermittent drops however and as mentioned there's nothing jumping out as being problematic when looking at your overnight noise margins. As the connection isn't currently dropping 3 times within 24 hour or 6 times within 72 hours then I'm afraid there's nothing we can do to progress this issue further on our suppliers side. I'd recommend then, should the drops look to worsen moving forwards to within our required drop amounts to please get back in touch so we can look  to raise a fault on our suppliers side.
Unless the images are all placed into a zipped folder or something I'm not sure there's away to attach more than one image at a time however edits are always welcome where needed.
 

[#3]

@BD  "In which case, I've bumped up the profile on the account which looks to  be limiting some of the download speed."

My speed is unchanged? Does it need resetting your end or mine to achieve the speed increase?

@Townman @Gandalf  Just to refresh, as the thread title is now a bit misleading! As a reminder, please see my post 91 and 95, explaining my current problem, though haven't seen it yet since new router.

My log from when OR completed the work

After reconnect to NEW line in manhole outside 17 March 2021 @ 1517

6 - Uptime:	0 days 00:01:19
7 - Data rate:	756/8336
8 - Maximum data rate:	1160/9008
9 - Noise margin:	8.5/9.1
10 - Line attenuation:	21.7/39.5
12 - Data sent/received:	152.9K/5.0M

Since then my max speed has decreased in stages

20 March 0916

6 - Uptime:	2 days 16:22:34
7 - Data rate:	756/8193
8 - Maximum data rate:	1176/8904
9 - Noise margin:	8.9/9.1
10 - Line attenuation:	21.7/39.5
12 - Data sent/received:	455.8M/1.9G

23 April 1032

6 - Uptime:	12 days 04:12:09
7 - Data rate:	756/8065
8 - Maximum data rate:	1160/8840
9 - Noise margin:	8.7/9.1
10 - Line attenuation:	21.8/40.0
12 - Data sent/received:	1.5G/3.6G

12 May 0718

6 - Uptime:	1 days 14:23:48
7 - Data rate:	756/7955
8 - Maximum data rate:	1156/8768
9 - Noise margin:	8.8/9.1
10 - Line attenuation:	22.1/40.5
12 - Data sent/received:	714.8M/1.0G

17 May 1702 after restarting router from advanced settings

6 - Uptime:	0 days 00:01:13
7 - Data rate:	756/8178
8 - Maximum data rate:	1156/8852
9 - Noise margin:	8.3/9.1
10 - Line attenuation:	22.0/40.0
12 - Data sent/received:	185.1K/309.4K

7 June 2050

6 - Uptime:	14 days 14:35:11
7 - Data rate:	756/8050
8 - Maximum data rate:	1160/8528
9 - Noise margin:	6.8/8.5
10 - Line attenuation:	22.0/40.0
12 - Data sent/received:	2.6G/594.2M

10 June homehub fitted.

11 June 1110

6. Data rate:828 / 7256

7. Maximum data rate:21215 / 7576

8. Noise margin:10.5 / 9.8

9. Line attenuation:21.8 / 42.0

10. Signal attenuation:21.8 / 40.4

11. Data sent/received:292.6 MB / 2.6 GB

Today, 14 June 0935, still same at 828/7256. Is my download now fixed at this lower level?

Apologies if all those older logs are irrelevant, I thought better to submit them and let you decide.

Regarding the degradation overnight, if it is due to MW interference, how can it be filtered out if it is actually co-channel on the frequency of broadband?

Many thanks, Rob

Here are the overnight logs.

[#4]

@joseph1 wrote:

@BD  "In which case, I've bumped up the profile on the account which looks to  be limiting some of the download speed."

My speed is unchanged? Does it need resetting your end or mine to achieve the speed increase?

Yeah you'll need to reboot your router to accept the new change in profile we've made on our systems

Just to refresh, as the thread title is now a bit misleading! As a reminder, please see my post 91 and 95, explaining my current problem, though haven't seen it yet since new router.

Thanks for the heads up. 

Today, 14 June 0935, still same at 828/7256. Is my download now fixed at this lower level?

We haven't actually changed your sync speed, Ben's increased a profile on your account from 6.4mbps to 7.2mbps which may had been limiting your throughput although I believe 6.4 was correct because it should always match the IP profile of a line, which is normally around 88.2% of a sync speed.

With the new router, what does your throughput look like on a speed test? I'd run one Here.

Also I can't remember if this has been suggested but have you considered upgrading to fibre broadband? The speeds you can get are a lot higher and you likely wouldn't experience the problems you're having now. Looking at the estimated fibre speed range for your line, you should be able to get a speed of around 32.4mbps or more. 

[#5]

---

@BD wrote:

When looking over your connection this side I can see currently the speed profile on your account looks to be set to 6.4Mbps despite your sync speed being 7.2Mbps. In which case, I've bumped up the profile on the account which looks to  be limiting some of the download speed.

As the connection isn't currently dropping 3 times within 24 hour or 6 times within 72 hours then I'm afraid there's nothing we can do to progress this issue further on our suppliers side.
 

---

@BD 

Hi Ben,

For a line sync'd at 7.2mbps a profile of 6.4mbps would be quite appropriate.  Does this user have a static IP address?

The elevated SNRM might well be making other issues, giving rise to the perception of increased stability at the expense of sync speed.  The stats history clearly shows a degradation of sync speed with a rising SNRM.

The router stats noise margin plots graphically show an increased susceptibility to noise during the hours of darkness, abating with sunrise, SNRM rising a little and becoming much more stable.  Previous experience might infer an AC balance issue.  Has such been eliminated?

@joseph1 

Rob, you might care to restart the router around midday.  That will establish the best attainable sync speed and set a new benchmark for review.  If the target SNRM is indeed 6dB you should see more sync speed and during the hours of darkness, you'll get a true measure of the impact of noise, possibly leading to disconnections ... and BTOR exposure to action.

Edit: Anoush's comment was not there when I started my post!

[#6]

@Townman wrote:
Edit: Anoush's comment was not there when I started my post!

I'm always one step ahead of you

[#7]

 @Gandalf @Townman 

Thanks again both of you. Really appreciated.

Just done the BT speed test and it gives 6M D/L, 0.59M U/L

I remember when the BT/OR guy was here working he did say something about made a change from 6dB to 9dB. You probably know what this was.

I will restart shortly after 1200.

FTTC is something we never really considered as until the problems started everything was fine. Not ones for lots of streaming, just usually a bit of itv hub & iplayer the wife uses time to time. Otherwise, email and browsing. Rarely use youtube though.

Just been looking up some terms I am unfamiliar with, such as profile.

Am I on ADSL2+ and is DLM applied?

BTW, I much prefer radio communication repair work. I have done it 55 years!

Thanks, Rob

Latest stats added.

[#8]

Ah OK, no problem Rob. 

I remember when the BT/OR guy was here working he did say something about made a change from 6dB to 9dB. You probably know what this was.

Moving the signal to noise ratio from 6dB to 9dB would artificially compensate for any noise on your line

Just been looking up some terms I am unfamiliar with, such as profile.

https://kitz.co.uk/ is a good resource of information

Am I on ADSL2+ and is DLM applied?

Yep to both. We can't actually turn off DLM

[#9]

@Gandalf 

"Moving the signal to noise ratio from 6dB to 9dB would artificially compensate for any noise on your line"

Does this mean it is used as a form of trigger level for reducing my max speed using DLM if my noise margin drops too low to sustain the higher speed? When problems were bad around Xmas, my speed would often change, sometimes to over 10M, but the noise margin would be around 5dB. Then often overnight it would drop out. When I reset the router, it might then be 1M or so lower for a while.

The big problem for me was needing to manually reset the router nearly every time it dropped out as it would not do it automatically most of the time. Do you know if my hub one will reset automatically if it drops out due to noise on my line?

Or am I misunderstanding? As I said, these terms are all a new learning curve.

Thanks, Rob

[#10]

@joseph1 wrote:

"Moving the signal to noise ratio from 6dB to 9dB would artificially compensate for any noise on your line"

Does this mean it is used as a form of trigger level for reducing my max speed using DLM if my noise margin drops too low to sustain the higher speed? When problems were bad around Xmas, my speed would often change, sometimes to over 10M, but the noise margin would be around 5dB. Then often overnight it would drop out. When I reset the router, it might then be 1M or so lower for a while.

Sort of. DLM's active on a line all the time and if there's noise, errors, drops etc it'll increase the noise margin to try to artificially combat them which in turn would lower your speed down.

The big problem for me was needing to manually reset the router nearly every time it dropped out as it would not do it automatically most of the time. Do you know if my hub one will reset automatically if it drops out due to noise on my line?

Really odd. The router should automatically start back up again if the connection drops. 

Having to continually reboot the router to get a connection back could be indicative of a router issue.

As I said, these terms are all a new learning curve.

No problem Rob. 

I'd also take another thought at fibre as there are other reasons for upgrading not just for faster speeds but greater reliability. I can't guarantee this particular problem won't follow you across to fibre but there'd be a very good chance it won't. 

[#11]

Rob,

FTTC - all very much depends on where your green cabinet is and which side of your current circuit is picking up the noise. For ADSL the max speed is limited by the total distance between the exchange and your home. With FTTC it is between the cabinet and home. FTTC speeds fall off more markedly over shorter distances. If you are more than 1.5km from the cabinet FTTC might not be significantly faster than ADSL.

If the noise ingress is on the cabinet to home leg of the circuit it will probably impact FTTC similarly.

The question on susceptibility and AC balance needs to be considered and eliminated for consideration.

Answering your general question: where a line is susceptible to noise ingress, if when the line resyncs there is no noise and the target SNRM is say 6dB then 3dB or more of noise occurring later (for example at night) might be enough to drop the connection. Changing the target to 9dB (at lower speed) might avoid such instability.

[#12]

OK.

Using google maps /distance, the total distance from my house to exchange following the cable route by street is 1.85km. From my home to the cabinet is 655m. The only above ground is from base of the pole at front of my house to where it enters at the back, a run of approx 35-40M. The cable was replaced from top of pole to indoors during earlier problems around 10 years ago.

Electric supply is underground and is run on the opposite side of the road.

Using an old portable radio tuned to 612KHz (I checked exactly using a digital signal generator) near my old type electric meter in garage wall box, you need to be within half a metre to pick up noise. I am happy that I have checked my own rensonsibilty regarding noise generation from electrical items. There is far more noise when near the capping that runs up the OR pole at the top of the drive. This noise is apparent in a large area of the footpath out front, but difficult to determine what it is, it is of a pulsating buzzing level. There are 5 other dropwires to neighbours as well as mine. Placing my radio on top of the OR concrete cover in the path, very faint varying tones can be heard, which I assume is the BB signal below. I'm pretty sure the OR guy commented on noise locally, but cannot be more specific.

"The question on susceptibility and AC balance needs to be considered and eliminated for consideration." How is this achieved? Anything I can do?

Thanks, Rob

2 RS screens attached.

[#13]

Hi Rob,

That line attenuation suggest a line length more like 3km - which might infer an issue!!

AC balance, no nothing you can do, I'm hoping a staffer will take the bait, but the are [wisely?] ignoring it.

If this line is not banded, I'd like to understand why the resync came back up at circa 9.8 dB, which is not a recognised SNRM target.

Can you please share the sync speed plot for the router restart - I anticipate that it showed the same sync speed before and after the router restart!

It would also be helpful if you can find the xDSL session start record from the router log file.  That will contain the line's profile and SNRM targets.

Does you RFI "detector" provide an objective means of measuring the level of RFI?  If yes, it would be interesting to measure the levels during day light and during the hours of darkness.  That said the level of noise being plotted ought not to cause xDSL drops with a 6dB target SNRM, so I suspect that there must be another source of FRI which we have not yet seen on the plots.

[#14]

@Townman 

"It would also be helpful if you can find the xDSL session start record from the router log file.  That will contain the line's profile and SNRM targets."

Any ideas where that is please? google didnt help!

Sorry, unable to measure the rfi as my equipment needs a calibrated standard as a reference and is matched to a 50 ohm impedance. Most suited to bench measurements, not field as it is mains powered and quite large.

Connection speed at reset as attached as first screen.

Been two strange RS screens of UPloads since the reset! See the 2 noise margin screenshots attached.

Thanks, Rob

[#15]

@Townman 

Yes, that line loss is excessive.

Info here suggests a lot lower would be expected:

https://www.increasebroadbandspeed.co.uk/graph-ADSL-speed-versus-line-loss-distance

Thanks, Rob