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SNR/Connection speed wobble.

jab1
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Re: SNR/Connection speed wobble.

@ejs Thanks for your helpful reply. If you had bothered to read my posts on here from, say, the beginning of August, you would see there is a definite, but so far unexplained, pattern of very late night/early morning interference from somewhere. During the rest of the time, things are fairly stable.

This night-time behaviour is what I am trying to fathom - if you have anything useful to say on that, please share.

 

John
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Re: SNR/Connection speed wobble.

I have seen the graphs but do not agree with the conclusion that it must be an interference problem. I think @Townman has just assumed it is an interference problem and then continued to interpret everything under that assumption. Even if it is interference, how do you know the problem is not actually completely normal levels of interference, which may have always been present, now acting on a bad line?

I guess some people have never experienced what appears as an interference problem disappear after poking about in a box of wires, after which the interference is still there but no longer causing any issues.

jab1
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Re: SNR/Connection speed wobble.


@ejs wrote:

I have seen the graphs but do not agree with the conclusion that it must be an interference problem. I think @Townman has just assumed it is an interference problem and then continued to interpret everything under that assumption. Even if it is interference, how do you know the problem is not actually completely normal levels of interference, which may have always been present, now acting on a bad line?

I guess some people have never experienced what appears as an interference problem disappear after poking about in a box of wires, after which the interference is still there but no longer causing any issues.


Re the bolded bit, I find it difficult to believe it is 'completely normal levels of interference', given that it occurs during a specific time period, and then completely disappears outside that period. If it is normal, why does it not happen all the time?

John
jab1
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Re: SNR/Connection speed wobble.

I seem to be unfortunate with RSL - it stopped again last night at around 2230. I have captured the router log as far back as I can, but still lost about 3 hours of information due to the limitations of the said logs.

Log1.PNGLog2.PNGLog3.PNG

@Townman As you can see - turning off the PIR lights has not helped.Sad

John
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Re: SNR/Connection speed wobble.

@jab1 

Well it has eliminated that as a potential source.

Are you up for installing the full version of RS.

If you really want to get to the bottom of this, rather than "living with it" on your "bad line" then it will be a matter of trying to eliminate anything which at the moment you believe to not be the cause.  From my own experience, I finally located the cause of my dusk time REIN by turning off something which "it just could not be" as that was on all of the time.  However during darkness, its power consumption was quite different.

 

@ejs 

Alternative enlightenment is always welcome.  How do you interpret the situation?

  • The whole E-side / D-side circuit has been swapped
  • There has been a lift n shift done
  • There is no general noise on the line
  • The graphs show two distinct events

I concur that the search might turn up nothing or identify something which cannot be fixed and will have to be lived with … my own experience was passing West Coast mainline super pedolino trains.  These graphs do not show any significant variation in SNRM other than the xDSL down events; on a "bad line" surely we would expect to greater variations?

jab1
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Re: SNR/Connection speed wobble.

Thanks for replying so quickly, Kevin.

If it would possibly help, I am happy to install the full version of RS - I'm fairly certain it can't be that hard.

As you say, we have eliminated the PIR as a potential source, but I'm wracking my brain to try and identify anything within my property/control which could have an effect such as this. The only things at home which are 'live' 24/7 are the previously mentioned fridge/freezer, the router, a TV (on standby 99% of the time) and the DECT phones.

John
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jab1
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Re: SNR/Connection speed wobble.

@Townman RS 7.0 now dowmloaded. I know you have produced a set-up guide, which I have looked at, but that was some time ago, and for a Netgear router and quite a while back. Just wish my DG832 hadn't died.Sad

John
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Re: SNR/Connection speed wobble.


@jab1 wrote:


Re the bolded bit, I find it difficult to believe it is 'completely normal levels of interference', given that it occurs during a specific time period, and then completely disappears outside that period. If it is normal, why does it not happen all the time?


What I'm thinking of is: whatever it is only happens at those times during the night. It would have a negligible affect on a normal line, but knocks out your line. There must be plenty of things that people might schedule to only be done during the night. I really don't think that the fact it only happens at night means that the level of interference generated is unacceptably high.

jab1
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Re: SNR/Connection speed wobble.

Whilst I now completely understand what you mea, @ejs , I can't quite see what that may be. I am well away from any industrial location, train services around here are not electric and only run three times in each direction per night, and the only facility I can think of that could be a culprit - a large electricity substation - only has work done on it during the day, barring a failure.

John
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Re: SNR/Connection speed wobble.

One of the shapes seen on the DS SNRM graphs looks much the same as the ones in this previous thread:

https://community.plus.net/t5/ADSL-Broadband/Erratic-U-S-SNRM-and-resulting-DLM-interventions/td-p/1...

 

If it's getting increasingly difficult to imagine what source of interference could be responsible for the observed effects, maybe there is no source of interference and the problem is something else.

jab1
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Re: SNR/Connection speed wobble.

Again, I agree with you Smiley - but what the blazes could it be?UndecidedUndecided

John
jab1
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Re: SNR/Connection speed wobble.

I now these posts are getting boring, so if you want me to stop, say so.

Last night/early this morning:

NOTE: this is with PIR lights still off

ConnectionSpeed-2019Aug16-2324.jpgNoiseMargin-2019Aug16-2324.jpgConnectionSpeed-2019Aug17-0124.jpgNoiseMargin-2019Aug17-0124.jpgConnectionSpeed-2019Aug17-0324.jpgNoiseMargin-2019Aug17-0324.jpg

 

John
jab1
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Re: SNR/Connection speed wobble.

@LordFoul , @RandallFlagg Can you please 'undo' whatever it was your CSC analyst did Saturday morning 17/08/19 at around 0920.
Whatever it was has upped my SNR to 15 and reduced my connection speed to 7.8 Mbps.
He did this without confirming with me it was OK - not good practice!
Unfortunately, nor did he create a ticket on my account to explain his actions (more bad practice), so you will have to listen to the phonecall, which started around 0915, and his callback to me around 0927?

The above SNR margin and connection speed was maintained flawlessly until the event in the graphs below, so his action has obviously undone the pinning of my margin - not happy, again.

Unfortunately, RSL threw an exception at the time of this interference and I had to restart the machine, so there is no plot showing exactly when this occurred.

I will not maintain these levels, and am going to be subject to more wild, unpredictable swings during the day. I didn't object to the xDSL changes overnight particularly as they didn't disturb my browsing, but when they occur at times I am using the machine, they are extremely annoying.

ConnectionSpeed-2019Aug19-0603.jpgNoiseMargin-2019Aug19-0603.jpg

John
jab1
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Re: SNR/Connection speed wobble.

Further to my post above - it has started! Had a re-sync at 0803 which has upped the SNR to ~15dB and reduced the connection speed to 8.9Mb/s.

John
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Re: SNR/Connection speed wobble.

Hi John,

There is some possibility that the DSLAM just did its own thing here.  Aside from the transients, your line looks fairly stable at 12dB therefore an attempt to change the target SNRM is not entirely unexpected … but your line should have been glued to 12dB.

That said, there has been some marked variability in the US SNRM, which was a key characteristic of your line earlier.  I think it would be very helpful if you can get the FEC monitoring working please.  You might also care to lose the average line as they add nothing to the story.  Can you please check the axis settings on all graphs to ensure that both US and DS values are plotted on both the SNRM and sync speed plots. 

How well do you know  your neighbours?  Is there any chance of you getting RS monitoring set up with them to monitor their lines as well as your own?  Seeing the issue on several lines in the area might be helpful in seeking to get BTOR "out of bed" on this one.  If this is viable, you could look at using a shared drop box folder as the storage location for the graphs … so you can see what is happening without needing to go visit them every day.

Who is the local power supplier?  Have you put a report into the local power network supplier advising that you suspect that their equipment might be interfering with telecommunications services?  I have found SPEN (in my area) to be exceedingly helpful.

@RandallFlagg @LordFoul @Mads 

Could answers be provided please to the technical questions asked a few posts back please?

What are the next steps on this please?  A BT engineer visit has been suggested, but even if you can get a REIN specialist on the case unless they are prepared to attend through the night, there is very little chance of locating the cause of the interference.