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Author Topic: Death of my line #4  (Read 2572 times)

Weaver

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Death of my line #4
« on: February 15, 2021, 03:50:09 PM »

My line #4 is going on and off constantly, losing sync all the time. Started yesterday at around 18:00. Has been reported to ISP, A&A, who are waiting for Openreach to come back to them with an engineer appointment date.



Meanwhile line #3 is a bit slow due to hollow curve malaise, that is: a misshapen SNR-vs-tones graph where there is a depression or hollow where the highest point of the curve should be. It’s down at downstream sync rate of ~2400kbps whereas it should be around 2900-3100 kbps compared to its previous state and compared to lines 1 and 2.

I think it’s very suspicious that line #4 failed when the thaw here began. Everything has been frozen solid here for week or so, and we have no water as there is ice in the pipes. Even though the thaw started seriously on Saturday it’s taking a long time for the warmth to reach certain parts of the plumbing system. What if water had got into a connection somewhere, then had frozen solid, and on Sunday it finally turned into liquid water again. The speed of line #4 downstream has been an all time record.

These are the sync rates before things went bad this weekend, and before line #3 went really bad (although line #3’s hollow curve phenomenon was evident already at that time and was responsible for line #3’s lower speed compared to lines #1 and #2)

Live sync rates:
  #1: down 3165 kbps, up 531 kbps
  #2: down 3154 kbps, up 586 kbps
  #3: down 2869 kbps, up 409 kbps
  #4: down 3392 kbps, up 582 kbps

That high sync rate was unheard of, scarily fast, and the link was completely stable, holding up at 3dB target SNRM for a couple of months (very roughly).
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burakkucat

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Re: Death of my line #4
« Reply #1 on: February 15, 2021, 05:15:20 PM »

Hmm . . . I'm not sure what could be the cause. Please provide an update when something occurs.
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Weaver

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Re: Death of my line #4
« Reply #2 on: February 15, 2021, 05:31:19 PM »

Openreach SFI engineer booked for the crack of dawn tomorrow morning, ie Tuesday.
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Alex Atkin UK

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Re: Death of my line #4
« Reply #3 on: February 15, 2021, 08:06:04 PM »

What if water had got into a connection somewhere, then had frozen solid, and on Sunday it finally turned into liquid water again. The speed of line #4 downstream has been an all time record.

When your lines are so bad that ice is a better conductor than the phone line itself? ;)
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Weaver

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Re: Death of my line #4
« Reply #4 on: February 16, 2021, 08:38:16 AM »

@Alex I agree, it doesn’t make sense. More like, it could be someting to do with the alteration of the electrical environment around the conductors, changing impedance or who knows what, when it’s surrounded by ice. Or could be a change in the interference-shielding capabilities of the system, so maybe ice screens off rf interference. Speculating wildly. But something has been pushing up the downstream sync rate to such an unheard of high value.
« Last Edit: February 16, 2021, 08:44:33 AM by Weaver »
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Weaver

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Re: Death of my line #4
« Reply #5 on: February 16, 2021, 01:34:25 PM »

Our excellent BT OR engineer was examining things outside, decided to replace the NTE for line 4, so he told Janet.

Downstream sync speed now is absolutely unbelievable, even higher than before, passed the 3.4Mbps mark: 3403 kbps ! New all-time highest record for any line.

Latest stats:

xdslctl: ADSL driver and PHY status
Status: Showtime
Last Retrain Reason:   8000
Last initialization procedure status:   0
Max:   Upstream rate = 521 Kbps, Downstream rate = 3692 Kbps
Bearer:   0, Upstream rate = 579 Kbps, Downstream rate = 3403 Kbps

Link Power State:   L0
Mode:         ADSL2 Annex A
TPS-TC:         ATM Mode(0x0)
Trellis:      U:ON /D:ON
Line Status:      No Defect
Training Status:   Showtime
      Down      Up
SNR (dB):    3.1       5.9
Attn(dB):    63.0       39.7
Pwr(dBm):    18.7       12.4

         ADSL2 framing
         Bearer 0
MSGc:      52      13
B:      39      62
M:      4      1
T:      3      1
R:      10      14
S:      1.4831      3.4222
L:      917      180
D:      2      8

         Counters
         Bearer 0
SF:      236536      236077
SFErr:      0      12
RS:      10289344      186863
RSCorr:      189      2624
RSUnCorr:   0      0

ReXmt:      74      0
ReXmtCorr:   71      0
ReXmtUnCorr:   0      0

         Bearer 0
HEC:      0      19
OCD:      0      0
LCD:      0      0
Total Cells:   30803284      5243132
Data Cells:   246681      201958
Drop Cells:   0
Bit Errors:   0      1542

ES:      24784      986
SES:      10027      0
UAS:      122318      114065
AS:      3838

         Bearer 0
INP:      26.00      2.00
INPRein:   0.00      0.00
delay:      8      7
PER:      16.12      16.25
OR:      28.76      9.35
AgR:      3417.30   586.79

Bitswap:   483/483      7/7

Total time = 36 days 6 hours 3 min 10 sec
FEC:      109827      992005
CRC:      3439      610
ES:      24784      986
SES:      10027      0
UAS:      122318      114065
LOS:      1040      0
LOF:      2047      0
LOM:      310      0
Latest 15 minutes time = 3 min 10 sec
FEC:      6      64
CRC:      0      0
ES:      0      0
SES:      0      0
UAS:      0      0
LOS:      0      0
LOF:      0      0
LOM:      0      0
Previous 15 minutes time = 15 min 0 sec
FEC:      61      298
CRC:      0      0
ES:      0      0
SES:      0      0
UAS:      0      0
LOS:      0      0
LOF:      0      0
LOM:      0      0
Latest 1 day time = 6 hours 3 min 10 sec
FEC:      191      2655
CRC:      373      12
ES:      55      14
SES:      50      0
UAS:      11001      10951
LOS:      5      0
LOF:      44      0
LOM:      0      0
Previous 1 day time = 24 hours 0 sec
FEC:      0      0
CRC:      0      0
ES:      12707      311
SES:      5475      0
UAS:      75857      71605
LOS:      398      0
LOF:      1092      0
LOM:      167      0
Since Link time = 1 hours 3 min 57 sec
FEC:      189      2624
CRC:      0      12
ES:      0      8
SES:      0      0
UAS:      0      0
LOS:      0      0
LOF:      0      0
LOM:      0      0
NTR: mipsCntAtNtr=0 ncoCntAtNtr=0
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jelv

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Re: Death of my line #4
« Reply #6 on: February 16, 2021, 02:18:39 PM »

When your lines are so bad that ice is a better conductor than the phone line itself? ;)

There's another solution that might prove more reliable than Weaver's lines!  ;D

https://www.revk.uk/2017/12/its-official-adsl-works-over-wet-string.html
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Weaver

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Re: Death of my line #4
« Reply #7 on: February 16, 2021, 09:44:43 PM »

It all started this time last year. There are quite a few joints in such a long 7300m / 4.54 mi line.


In this photo line 4 is on the left. There are labels on the top surface which you can’t see because of the unhelpful angle of the shot.

I doesn’t look like the engineer changed anything at all because the label that Janet put on the back saying "line 4" is still there, and that would have gone if the back had been replaced. So I’m confused. Perhaps when the engineer’s notes come back then there will be some clarification.
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Weaver

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Re: Death of my line #4
« Reply #8 on: February 17, 2021, 12:04:52 PM »

AA has called in OR for line 3 slowness, waiting for a date for SFI. Engineer’s notes for line 4 are below, but very unhelpful :

Note Below are the engineer notes: 11:36:54 16/02/2021 11:36

(No manually entered closure notes)
2021-02-16T11:36:00 -

(no closure notes!)

Did you remove one or more amber parameters on a pair quality test ? - Yes
Have you successfully demonstrated connectivity to the NTE ? - Yes
Did all the connections, extensions and DSL filters meet the minimum standards ? - Yes
Have you conducted a sync test (modem light on) ? - Yes
What was the result of the initial pair quality test ? - Pass
Did you complete the Frames module ? - No
Did you complete the Network module ? - No
Did you complete the Base module ? - Yes
Did you complete the end customer Premises Wiring Module ? - No
Did you complete the end customer Premises Equipment Module ? - No
===QBC Summary Start===
Customer Report: End customer informed us that broadband is not stable intermittent. Initial test results: PQT test performed at NTE back plate. The test passed with amber parameters on 2021-02-16T09:00:54. Actions to uplift Openreach customer network: Engineer has uplifted the OR network to improve speed / stability by replacing NTE or NTE micro filters. Identified and improved PQT amber parameters. Advice given to end customer: Length of line (short / long line) causing the slow speed. Final test results: Final PQT performed at the NTE back plate. The test passed with amber parameters on 2021-02-16T09:19:23. Final FastTest completed. The test passed on 16/02/2021 11:28:42.
===QBC Summary End===



Engineer is booked for Line 3 tomorrow morning (Thursday).
« Last Edit: February 17, 2021, 08:42:23 PM by Weaver »
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Weaver

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Re: Death of my line #4
« Reply #9 on: February 18, 2021, 04:41:38 PM »

The same OR engineer came back to sort line 3 this morning with an excellent result, full speed restored.

Sync speeds at 3dB target SNRM:

  #1: down 3165 kbps, up 531 kbps
  #2: down 3154 kbps, up 586 kbps
  #3: down 2982 kbps, up 399 kbps
  #4: down 3403 kbps, up 579 kbps
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