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Broadband Related => ADSL Issues => Topic started by: Weaver on October 26, 2021, 04:10:01 PM

Title: Intense Rain and the n+1th "Hollow-Curve Phenomenon"
Post by: Weaver on October 26, 2021, 04:10:01 PM
Intense rain for well over a week, and squally winds. Janet said she saw some of the heaviest rain in her experience the day before yesterday. I slept through that, missed it. We have some happy visitors staying in one of Janet’s shepherd huts. They were warned in advance about the utterly vile forthcoming weather and don’t care, they have their books and have done a bit of cooking and been plying my wife with drink. We have a lounge / kitchen / bathroom for guests’ use in a very big shed that we built originally as an equipment store room.

My line #2 has once again developed a case of ‘SNRM hollow curve’ syndrome, which has knocked the highest downstream tones 49-95 down by four bits, from 11 bits to 7, so that’s something like 300k out of 2.7 Mbps, so now down to 2.4 Mbps after a forced resynch. The d/s SNRM started falling at 1800 UTC yesterday evening and continued falling until midnight. In the early hours I discovered the d/s SNRM was only at 0.5 dB, down from 3dB, with a vast error count downstream, so I forced a resync, back up to 3dB d/s SNRM, and all was again well. This hasn’t happened for a while now. Could it be due to intense rain, water getting in somewhere?

I’m talking to A&A about it, yet again. It’s the same old story. Send for OR engineer; he/she does tests, does nothing that ought by rights to be effective, but the problem is always fixed, by magic. And is fixed somehow either before engineer arrives, or during initial procedures, before test results come in. A visit has never failed to fix it. I can’t remember clearly, but I have some vague notion that A&A may have once fixed it remotely, presumably by the effect of firing up whatever remote tests they can initiate.


The CRC count is still really quite bad this afternoon, so I’ve had to raise the d/s target SNRM up to 6dB to fix it. So even more speed lost.
Title: Re: Intense Rain and the n+1th "Hollow-Curve Phenomenon"
Post by: burakkucat on October 26, 2021, 04:30:56 PM
Could it be due to intense rain, water getting in somewhere?

I suppose it could be a possibility.

A while back I speculated that a burst of AC, at a highish voltage, might fix it . . . purely because that is the one thing your lines never have - the ringing voltage is never applied to the pairs.

(If "The Cattery" was local, I would be willing to visit and give the pair a burst of AC.)
Title: Re: Intense Rain and the n+1th "Hollow-Curve Phenomenon"
Post by: Weaver on October 26, 2021, 04:42:10 PM
I remember that we discussed this, and I myself was very much in favour of it; is it something an ISP can trigger remotely by happy chance ?
Title: Re: Intense Rain and the n+1th "Hollow-Curve Phenomenon"
Post by: burakkucat on October 26, 2021, 04:49:57 PM
Perhaps A&A can give you a customised "Control Panel", one that has a button which causes the standard telephony ringing voltage to be applied to a nominated pair for, say, 60 seconds?
Title: Re: Intense Rain and the n+1th "Hollow-Curve Phenomenon"
Post by: Weaver on October 26, 2021, 05:07:44 PM
Do they just need to call my modem? Or do I need a telephone to do it from my end?
Title: Re: Intense Rain and the n+1th "Hollow-Curve Phenomenon"
Post by: burakkucat on October 26, 2021, 05:20:34 PM
Do they just need to call my modem? Or do I need a telephone to do it from my end?

Ideally the "Faultsman's Ring-Back" would do the job but as you don't have an active telephony service on each of the three pairs it can't be initiated from a telephone at your end.

If A&A have access to the Openreach test access matrix (TAM) at the NSBRD exchange, they should be able to remotely "do something".
Title: Re: Intense Rain and the n+1th "Hollow-Curve Phenomenon"
Post by: Weaver on October 28, 2021, 10:03:54 AM
AA put the downstream target SNRM back down from 6dB to 3dB, which I assume wasn’t intentional, although they did say ‘got a bit more speed’. After that, the modem was reporting ~2k uncorrected downstream CRC errors per hour, which I decided was not good at all, so I put the d/s target SNRM back to 6dB. The downstream sync rate is now 1.8 Mbps, so it has lost about 900 kbps. This could be below the FTR now - I haven’t checked. I proposed to AA that we just keep an eye on it for a while.


Downstream sync rate down to 1.647 Mbps, so very much into faulty territory, as always happens: the problem just gets worse over time. Have told AA no engineer before the 8th because my dear wife is in self isolation before going into hospital next week.



Down to 400 k d/s with 13 dB d/s SNRM and many link retrains. Have switched line #2 off for the weekend, as it’s disrupting the quality of the entire bonded pipe since there are still ES in link #2. Will need to switch it back on later for a while so AA can see it.
Title: Re: Intense Rain and the n+1th "Hollow-Curve Phenomenon"
Post by: Weaver on October 30, 2021, 01:58:19 PM
A thought, would it work if one of you good friends phoned the number with a telephone ? The Black Cat has the numbers, which I think may have been updated in the light of new line changes a couple of months ago. I can dig them out from somewhere.
Title: Re: Intense Rain and the n+1th "Hollow-Curve Phenomenon"
Post by: burakkucat on October 30, 2021, 04:13:33 PM
I can certainly initiate a call to each number but, as there is no associated telephony service on each line, I suspect the result will be that I hear a NU tone.

b*cat plods off to one of his telephones . . .
Title: Re: Intense Rain and the n+1th "Hollow-Curve Phenomenon"
Post by: burakkucat on October 30, 2021, 04:34:11 PM
The results obtained --

Tel. No Ending        Service Identifier        Drop / Pair        Result

     70                     @a.1                   1 / 1             ET
     75                     @a.2                   2 / 2             ET
     14                     @a.3                   1 / 2             NU
     44                     @a.4                   2 / 1             ET

Where "ET" is Engaged Tone and "NU" is Number Unobtainable Tone.
Title: Re: Intense Rain and the n+1th "Hollow-Curve Phenomenon"
Post by: Weaver on October 30, 2021, 10:59:40 PM
FYI, my friend, did we update your table a couple of months ago? Because I have a new line (poss #4 replaced, can’t remember) and line #3 is no more, only three in total now.

The drop + pair values are certainly correct, I see that.

I will recheck line 2 later on, as it’s disconnected now since it has become so bad, and Mrs Weaver, my assistant and chief cable puller, is heading for the Land of Nod. Or was until Beileag, sitting on a shelf by the bed, eating cat-crunchies, suddenly sneezed extremely loudly and made Janet jump out of her skin.
Title: Re: Intense Rain and the n+1th "Hollow-Curve Phenomenon"
Post by: burakkucat on October 31, 2021, 12:17:31 AM
FYI, my friend, did we update your table a couple of months ago?

Yes, we did. The line which returned the NU (number unobtainable) tone was annotated with a "defunct" suffix.
Title: Re: Intense Rain and the n+1th "Hollow-Curve Phenomenon"
Post by: Weaver on November 08, 2021, 02:51:49 AM
I never got this fault fixed, because Janet was going into hospital, so I couldn’t have engineers coming to the house, as there’d be no one to let them in.

And then guess what: on Friday night, line #4 went bad. Still usable, but now down to half speed downstream, with a high downstream SNRM too, of ~9dB; upstream is unchanged at the usual 0.39 Mbps sync rate. Upstream isn’t that great on that line, compensated for by line #1’s ~650 kbps. So now I’m running on 1.5 lines downstream with a downstream TCP payload throughput of about 3.8 Mbps which is very roughly ~1.0 OBs, where the new unit of downstream unveiled is one ‘Old (ADSL2) Burakkucat’.

Line #2 has been assumed unusable due to a high error rate and very low downstream speed (~400 kbps poss), so it has been unplugged for the last couple of weeks. Mind you, if it isn’t corrupting downstream packets at the moment, then its upstream would be worth having.

Will talk to AA this morning and finally give them the go-ahead to book engineers to come in asap, since Janet is now back home and recovering.
Title: Re: Intense Rain and the n+1th "Hollow-Curve Phenomenon"
Post by: burakkucat on November 08, 2021, 02:30:24 PM
. . . a downstream TCP payload throughput of about 3.8 Mbps which is very roughly ~1.0 OBs, where the new unit of downstream unveiled is one ‘Old (ADSL2) Burakkucat’.

That DS throughput served me well for many a year. If it wasn't for TalkTalk's plans to get all their users onto VDSL2 connections then I would still be using the ADSL2 service.

Quote
Will talk to AA this morning and finally give them the go-ahead to book engineers to come in asap, . . .

The more I think about this recurring problem, the more inclined I am to believe that it is related to the absence of occasional bursts of AC (ringing current) through the multitude of crimps in the pair(s).

Quote
. . . since Janet is now back home and recovering.

That is good to know.  :)
Title: Re: Intense Rain and the n+1th "Hollow-Curve Phenomenon"
Post by: g3uiss on November 08, 2021, 04:36:02 PM
I used to call that a wetting voltage, not heard that term for years
Title: Re: Intense Rain and the n+1th "Hollow-Curve Phenomenon"
Post by: jelv on November 08, 2021, 05:45:20 PM
I presume Weaver's lines don't have telephone numbers associated with them that he could ring - shame as that would definitely be worth a try.
Title: Re: Intense Rain and the n+1th "Hollow-Curve Phenomenon"
Post by: burakkucat on November 08, 2021, 06:36:53 PM
The lines do have telephone numbers allocated to them but they do not carry telephony services.
Title: Re: Intense Rain and the n+1th "Hollow-Curve Phenomenon"
Post by: Weaver on November 09, 2021, 12:32:41 AM
Burakkucat has all the phone numbers. I agree with his thinking on this.

Update: Today Janet plugged line #2 in, the first one to fail, after 9 days unplugged, and - tara[!] - it’s suddenly 100% perfect! I don’t know what has been done to it; maybe AA or someone effectively phoned the line, or initiated a disruptive test sequence. I did mention the wetting ring-ring theory to AA and told them it was only a hypothesis, but maybe they tried it.

So now we still have line #4 ill, at <50% of usual downstream sync - only 1.4 Mbps d/s sync instead of 2.9 Mbps. So that needs fixing by magic remotely or by an engineer visit. I sent AA the visual proof of the illness - an image of the SNR-vs-tones of the link from the Johnson custom firmware ZyXEL VMG 1312-B10A modem’s easy-stats service (as I have termed this Johnson server), image with a horrible shape and a deep hollow where the max downstream bit loading should be, in the tones 40-90; 11 bits per bin down to 4/5.
Title: Re: Intense Rain and the n+1th "Hollow-Curve Phenomenon"
Post by: jelv on November 09, 2021, 09:28:59 AM
I did mention the wetting ring-ring theory to AA and told them it was only a hypothesis, but maybe they tried it.
If that's something they could do, you should be able to do it also. What happens when you dial one of the numbers? If it comes up number unobtainable I don't believe they could do it.
Title: Re: Intense Rain and the n+1th "Hollow-Curve Phenomenon"
Post by: burakkucat on November 09, 2021, 04:47:20 PM
What happens when you dial one of the numbers? If it comes up number unobtainable I don't believe they could do it.

Please review all that has previously occurred in this thread . . . In particular Reply #8 (https://forum.kitz.co.uk/index.php/topic,26443.msg443633.html#msg443633) and Reply #9 (https://forum.kitz.co.uk/index.php/topic,26443.msg443634.html#msg443634).  ::)
Title: Re: Intense Rain and the n+1th "Hollow-Curve Phenomenon"
Post by: Weaver on November 12, 2021, 12:00:12 AM
Engineer came on Wed afternoon and rang Janet ahead to tell her he was one hour’s drive away. I looked at the modem and it was perfect!

ayes, same story again.  Mystery fix, no clue how.

Engineer arrived, Janet and I told him the story, he tested everything as usual and told me he had superb figures for balance etc. We had a chat afterwards and I showed him the old SNR-vs-tones graph, as opposed to the now perfect current picture. He didn’t do anything notable before he came. I asked him about water ingress but we agreed that it had been raining heavily for weeks, so our mutually agreed conclusion was that that day was nothing special. I suggested to him that AA might have run some kind of remote test earlier in the day. Ahead later moaned to Janet about ISPs doing things that they ought not to, not that Janet was to blame for anything.  >:(

Later on I looked in the clueless.aa.net.uk log for the line; there were no relevant events that afternoon.

Emailed AA to tell them the story. engineer sent his notes in, the usual ‘no fault found’ which was quite correct.

So we’re now more bemused than ever. Could it be that unplugging a line from a modem might change things ?

Could it be a modem fault? Mind you, we would have to have two faulty modems, which seems incredibly unlikely, as there were two faults in the same week. Could a now-you-see-it-now-you-don’t modem h/w fault affect only tones 40-90 ?

For some reason, Janet talked me into swapping two of the modems: those labelled #3 and #4. This was a bad idea but I was very fuzzy, being bombarded, and agreed to something that I shouldn’t. When my mind cleared, I made Janet put the modems back the way they were. Now anyway, this involved possibly removing power from the modems, certainly unplugging each from its cables to the MUX/DEMUX VLAN switch that they’re connected to (between modems and the router).

So:
1. the line was disconnected from the modem (twice) - so a possible effect on the line, and
2. (possibly) the modem was rebooted (twice); in fact I’m pretty sure I remember seeing evidence that it did get rebooted because some of my network state overview programs moaned about not being able to access a modem.

So it just might be that some of those actions affected either the line or modem in some beneficial way. I can rule the modem out by swapping it for a new one, but I’m not remotely expecting to find anything as it just doesn’t feel like that kind of bug.

Perhaps we should go cargo-cult: have a fake engineer visit to fix the next fault - get a friend to drop in pretending to be an OR engineer and save AA some money.
Title: Re: Intense Rain and the n+1th "Hollow-Curve Phenomenon"
Post by: burakkucat on November 12, 2021, 04:56:52 PM
I am unable to think of any rational train of events that can account for the problems you are, quite clearly, experiencing at random times.  :-\
Title: Re: Intense Rain and the n+1th "Hollow-Curve Phenomenon"
Post by: Weaver on November 12, 2021, 08:53:21 PM
I’m wondering if the ‘cure’ is even correlated with any events happening around the time of the engineer coming out, or earlier, or while he/she is here. Is it possible that the problem is in some sense ‘fixed’ at an earlier time but I don’t know about it until some action is performed? - such as unplugging the line from the modem, or forcing a retrain, or even forcing a reboot. That is, the problem actually becomes ‘fixed’ earlier but I have no way of knowing about it/realising it until someone happens to do a certain something later.
Title: Re: Intense Rain and the n+1th "Hollow-Curve Phenomenon"
Post by: burakkucat on November 12, 2021, 10:41:46 PM
Yes, that is a possibility. But how can one test that scenario?  :-\

The next time you notice the problem, perhaps --
(Notice that I have deliberately suggested performing the first two steps the "wrong way round".)
Title: Re: Intense Rain and the n+1th "Hollow-Curve Phenomenon"
Post by: Weaver on November 13, 2021, 06:59:02 AM
Will definitely do exactly that. Thank you.

Title: Re: Intense Rain and the n+1th "Hollow-Curve Phenomenon"
Post by: Weaver on November 20, 2021, 07:17:28 AM
And guess what. On Thursday, the line #4 went back to its bad old ways but far far worse than ever before. A magnificent 242 kbps downstream. I now claim the title of slowest line of any kitizen! Can this be officially confirmed now please ;)

Have informed AA. Next I will follow Burrakucat’s procedure above.
Title: Re: Intense Rain and the n+1th "Hollow-Curve Phenomenon"
Post by: burakkucat on November 20, 2021, 04:20:40 PM
A magnificent 242 kbps downstream. I now claim the title of slowest line of any kitizen! Can this be officially confirmed now please ;)

Certainly.  :)

I have just had a sudden memory of using a remote full-screen editor, at 300 bps, way back in the 1980s.  :D
Title: Re: Intense Rain and the n+1th "Hollow-Curve Phenomenon"
Post by: Weaver on November 21, 2021, 11:54:47 PM
[ Dear admins, could we perhaps split off this recent slice of intense nostalgia for the horrible speeds of the Pre-Cambrian Era? ]

[Moderator note: Done. See Nostalgia - Networking in the "Early Days" (https://forum.kitz.co.uk/index.php/topic,26546.0.html).]



Have now completed the Burakkucat Procedure. Did indeed:
So modem is now back on. And once again it’s now perfect!!   :no: ;D

Sync: 3027 kbps down / 399 kbps up
Attainable: 3396 kbps / 328 kbps
SNR: 3.3 dB / 5.8 dB
Attenuation: 64.0 dB / 40.3 dB
CRC: 2 / 0
ES: 1 / 0
SES: 0 / 0
FEC: 161 / 38
Link Uptime: 2 hours, 3 minutes, 16 seconds


So many thanks to Burakkucat, whose instinct proved once again correct.
Title: Re: Intense Rain and the n+1th "Hollow-Curve Phenomenon"
Post by: Weaver on December 12, 2021, 06:05:28 PM
Discoveries:

1. I’ve found that a reboot does not clear the problem. ie using the modem’s command line reboot command via telnet.
   
2. A power-cycle does cure the problem! This is physically pulling out the dc for a very short time. I have not tried the modem’s on/off switch. Is that a simple mechanical switch? - as opposed to a reboot interrupt button which causes a controlled shutdown.

Janet doesn’t think the OR engineers turned off my modem. Indeed, she has a point: why would they.

So we ought to also test the following: 

3: test whether or not just pulling out the phone line alone fixes the problem. 
4: swap out the modem for one that has never been in use.

This way we can find out whether it is a modem gone bad or weirdness in the phone line. I think that when the big lightning strike happened in jan-feb 2020 (I forget the date, would have to look back) it is possible that all the modems got mildly ‘cooked’ so that even though they appear ok, there is actually something wrong with them, and this something causes the hollow curve phenomenon every once in a while. So will perform those tests as soon as I can procure the services of my beloved wife, who is knee-deep in govt paperwork.

So test 4 is important; it has to be a new modem, one that was not affected by the great lightning strike. I can’t just use modem #3 which was in use from before jan 2020 until summer 2021, and so was exposed to the strike.

So anyway, more tests to do but at least we have a fix now, one that we ourselves are in control of.
Title: Re: Intense Rain and the n+1th "Hollow-Curve Phenomenon"
Post by: tubaman on December 12, 2021, 07:13:22 PM
If a power cycle fixes the issue but a soft reboot does not then that suggests the soft reboot does not fully clear all memory etc.
I doubt it's a hardware fault but there's no harm in trying a different modem to be sure.
The power switch on the VMG1312-B10A is a mechanical switch that disconnects the 12V power so will perform the same function as removing the power adaptor from its 13A socket.
 :)
Title: Re: Intense Rain and the n+1th "Hollow-Curve Phenomenon"
Post by: burakkucat on December 12, 2021, 07:31:20 PM
I would be interested to know if number (3) resolves the problem . . . before progressing to number (4).
Title: Re: Intense Rain and the n+1th "Hollow-Curve Phenomenon"
Post by: Weaver on December 12, 2021, 10:18:16 PM
More news: total strangeness, and an answer to (3).

5) When modem #2 was power-cycled, it triggered an immediate hollow-curve phenomenon in modem #4 !!  I can see the hollow curve now. There was a burst of #4 FECs and CRCs at the exact power-cycle time followed by a linear rise over the next 90 mins of the observation period. The downstream #4 SNRM plunged vertically from 3.0 dB to 0.1 dB. BT forced a line #4 re-sync after nearly 5 hr at 0.1 dB downstream SNRM and correspondingly high error rates.

Modem #1 was fine; why one modem was cross-triggered and not the other is unknown.

6) Later this evening, Janet pulled the DSL line out of the afflicted line #4. This cured the hollow curve phenomenon (HCP). So that gives us an answer to another of our questions.

So seeing that pulling out the mains can cause HCP as well as curing it, is it a dangerous idea? A cure that we had discussed might aggravate the disease?

I believe that HCP was completely unknown before the great lightning strike. ( - is that correct ? ) A search through the forums might be very helpful but difficult.

We urgently need to swap out these modems to get some answers. I’ll see if I can arrange a modem swap-out tomorrow. I have a mountain of modems in my store. For some reason Janet calls my equipment store-chest or chests "Bert’s Barrow" - because we don’t know anyone called Bert and it doesn’t look like a barrow, so I’m stumped.
Title: Re: Intense Rain and the n+1th "Hollow-Curve Phenomenon"
Post by: burakkucat on December 12, 2021, 10:35:13 PM
Thinking scientifically, I have to ask the question: Do the experiments produce repeatable results?  :-\
Title: Re: Intense Rain and the n+1th "Hollow-Curve Phenomenon"
Post by: Weaver on December 12, 2021, 10:48:06 PM
I agree. I don’t think that some of the results are repeatable, yet to me it doesn’t matter in one sense, because a positive result proves that something is possible, and that is very interesting to me. For example, the difference between modem #1 and modem #4 behaviour is, I would expect, just due to random stuff.


Am I right in thinking that the HCP is a recent thing, completely unknown before 2020 ? Have I ever reported it, and have any other kitizens seen it ever? To qualify, someone has to show their bits-vs-tones or SNR-vs-tones (aka ‘vs bins’), and they only have to have a small hollow. Do not confuse the required shape with that caused by a pilot tone, or very narrow band interference from eg radio stations. The HCP only needs to be of modest width, say 15 tones, in the very early stages, but will be developing rapidly to cover tones 40-80 or 40-85 in the case of ADSL downstream. I have absolutely no idea if such a thing as VDSL2 HCP exists or is even possible.
Title: Re: Intense Rain and the n+1th "Hollow-Curve Phenomenon"
Post by: burakkucat on December 12, 2021, 11:16:43 PM
. . . to me it doesn’t matter in one sense, because a positive result proves that something is possible, and that is very interesting to me.

In that case, I must say "be aware of chasing your own tail" . . . for I have been in that situation. :graduate:
Title: Re: Intense Rain and the n+1th "Hollow-Curve Phenomenon"
Post by: Weaver on December 12, 2021, 11:21:41 PM
Heard and duly warned. It depends on what predicates you’re interested in, no?
Title: Re: Intense Rain and the n+1th "Hollow-Curve Phenomenon"
Post by: burakkucat on December 12, 2021, 11:38:48 PM
It depends on what predicates you’re interested in, no?

Absolutely, yes.
Title: Re: Intense Rain and the n+1th "Hollow-Curve Phenomenon"
Post by: Weaver on December 13, 2021, 04:49:01 PM
Have told AA that we now have a fix / workaround. I assume that they’re very relieved. I’m hopeful that swapping modems out altogether will make this whole issue go away, but that is just my optimism plus a desire for a plausible rational answer.

Luckily I have a huge stash of VMG 1312-B10A modems. AA once sold me one, whose config I used as the basis for all the others. I intend to label all the current four modems as “working:suspect / lightning: HCP: 2020 - 2021-12” and configure fresh ones out of my stash.
Title: Re: Intense Rain and the n+1th "Hollow-Curve Phenomenon"
Post by: Weaver on December 13, 2021, 10:42:03 PM
I am now told by my dearest that the source of the name is that there was originally a jute shopping bag which had "Bert’s Barrow" printed on it. Then it became full and so we had to get a large storage trunk made of willow which sits on the landing upstairs. This is the main equipment store. But original name stuck firmly. I never knew it’s meaning until today.
Title: Re: Intense Rain and the n+1th "Hollow-Curve Phenomenon"
Post by: Weaver on January 07, 2022, 07:24:52 PM
After, what, about four weeks, there has been another outbreak of hollow curve disease, on line #2 this time. Noticed this afternoon by Janet, who got an automated email from A&A saying line 2 had gone down a couple of times. Immediately cured by power cycling the modem. This was with very short off-time. The DSL line was plugged into the modem the whole time during this, not disconnected.
Title: Re: Intense Rain and the n+1th "Hollow-Curve Phenomenon"
Post by: burakkucat on January 07, 2022, 07:27:17 PM
Noted.
Title: Re: Intense Rain and the n+1th "Hollow-Curve Phenomenon"
Post by: Weaver on January 07, 2022, 09:21:29 PM
And I’m ashamed to say that I still haven’t replaced the current modems with new ones out of my store, my assistant having been so very poorly, the project has been postponed until better times.
Title: Re: Intense Rain and the n+1th "Hollow-Curve Phenomenon"
Post by: burakkucat on January 07, 2022, 09:32:32 PM
Would it, perhaps, be a more interesting experiment to replace just one of the modems? Keep notes over a, say, three month period of which circuits that show the "hollow-curve phenomenon".

If the circuit with the replaced modem still shows the phenomenon then it cannot be due to equipment malfunction.
Title: Re: Intense Rain and the n+1th "Hollow-Curve Phenomenon"
Post by: Weaver on January 07, 2022, 09:36:07 PM
Good point. Will do so. And NB: Recall that this never happened before 2020-01, indeed was completely unknown to science.
Title: Re: Intense Rain and the n+1th "Hollow-Curve Phenomenon"
Post by: Weaver on January 07, 2022, 10:22:56 PM
How long has line 2 been good for? I note that line #2 or is it line #4 that is the most recent line to have suffered from the disease? When was it ? - 2021-11-11 approx?

Note that unlike before, switching off line #2 has not triggered the disease in a different line.
Title: Re: Intense Rain and the n+1th "Hollow-Curve Phenomenon"
Post by: burakkucat on January 07, 2022, 11:25:08 PM
How long has line 2 been good for? I note that line #2 or is it line #4 that is the most recent line to have suffered from the disease? When was it ? - 2021-11-11 approx?

If it is not documented, earlier, within this topic then a search of your previous posts will be required.  :-X