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Author Topic: Odd-shaped SNR-vs-tone graph - line #2 now  (Read 1641 times)

Weaver

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Odd-shaped SNR-vs-tone graph - line #2 now
« on: June 11, 2020, 01:43:40 AM »

Nightmare. I have noticed that line #2 is now showing the symptoms that line #4 exhibited. Can’t tell when this started.
The downstream sync rate has dropped from 2.7Mbps to 2.593Mbps following a resynch. Live sync rates:
  #1: down 2807 kbps, up 519 kbps
  #2: down 2593 kbps, up 547 kbps
  #3: down 2964 kbps, up 389 kbps
  #4: down 2861 kbps, up 528 kbps

Here is the SNR-vs-tone graph for line #2. Note that for some reason the upstream (in green) values are all zero in this graph.



I have reported this to AA and they are looking into it. They ran some tests which gave now-you-see-them-now-you-don’t error reports.

Here are the line #2 detailed stats:

xdslctl: ADSL driver and PHY status
Status: Showtime
Last Retrain Reason:   8000
Last initialization procedure status:   0
Max:   Upstream rate = 499 Kbps, Downstream rate = 2800 Kbps
Bearer:   0, Upstream rate = 547 Kbps, Downstream rate = 2593 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):    2.8       5.8
Attn(dB):    65.0       41.6
Pwr(dBm):    18.3       12.4

         ADSL2 framing
         Bearer 0
MSGc:      55      12
B:      28      62
M:      8      1
T:      3      1
R:      16      14
S:      2.8182      3.6235
L:      704      170
D:      1      8

         Counters
         Bearer 0
SF:      2433900      361928
SFErr:      99      15
RS:      55675468      569814
RSCorr:      85423      4270
RSUnCorr:   100      0

ReXmt:      89281      0
ReXmtCorr:   89276      0
ReXmtUnCorr:   110      0

         Bearer 0
HEC:      109      18
OCD:      0      0
LCD:      0      0
Total Cells:   240910173      50935074
Data Cells:   91903637      10195572
Drop Cells:   0
Bit Errors:   3868      1572

ES:      171      18
SES:      26      0
UAS:      124      99
AS:      39456

         Bearer 0
INP:      28.00      2.50
INPRein:   0.00      0.00
delay:      8      7
PER:      16.11      16.30
OR:      30.27      8.83
AgR:      2612.76   554.19

Bitswap:   9547/9882      132/132

Total time = 22 hours 5 min 59 sec
FEC:      156127      7357
CRC:      1155      21
ES:      171      18
SES:      26      0
UAS:      124      99
LOS:      1      0
LOF:      9      0
LOM:      0      0
Latest 15 minutes time = 5 min 59 sec
FEC:      894      2
CRC:      4      0
ES:      3      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:      1989      12
CRC:      2      0
ES:      2      0
SES:      0      0
UAS:      0      0
LOS:      0      0
LOF:      0      0
LOM:      0      0
Latest 1 day time = 22 hours 5 min 59 sec
FEC:      156127      7357
CRC:      1155      21
ES:      171      18
SES:      26      0
UAS:      124      99
LOS:      1      0
LOF:      9      0
LOM:      0      0
Previous 1 day time = 0 sec
FEC:      0      0
CRC:      0      0
ES:      0      0
SES:      0      0
UAS:      0      0
LOS:      0      0
LOF:      0      0
LOM:      0      0
Since Link time = 10 hours 57 min 35 sec
FEC:      85423      4270
CRC:      99      15
ES:      96      13
SES:      0      0
UAS:      0      0
LOS:      0      0
LOF:      0      0
LOM:      0      0
NTR: mipsCntAtNtr=0 ncoCntAtNtr=0
« Last Edit: June 11, 2020, 02:16:13 AM by Weaver »
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burakkucat

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Re: Odd-shaped SNR-vs-tone graph - line #2 now
« Reply #1 on: June 11, 2020, 05:14:01 PM »

Oh, yuck.  :yuck:

Acknowledging the current problem but there is nothing new I can add.  :(
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Weaver

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Re: Odd-shaped SNR-vs-tone graph - line #2 now
« Reply #2 on: August 24, 2020, 03:30:32 PM »

The line 2 problem has worsened slightly, by about 2dB is my best guess.

Speed is currently : 2.362 Mbps downstream @ 3.1 dB SNRM, 544 kbps upstream @ 5.9 dB SNRM. Should be around 2.8 Mbps downstream if not more.

Here’s the SNR vs tones graph for line 2:





Full stats:

xdslctl: ADSL driver and PHY status
Status: Showtime
Last Retrain Reason:   8000
Last initialization procedure status:   0
Max:   Upstream rate = 502 Kbps, Downstream rate = 2572 Kbps
Bearer:   0, Upstream rate = 544 Kbps, Downstream rate = 2362 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):    3.0       5.9
Attn(dB):    65.5       41.9
Pwr(dBm):    18.1       12.4

         ADSL2 framing
         Bearer 0
MSGc:      51      12
B:      27      62
M:      8      1
T:      3      1
R:      16      14
S:      2.9860      3.6450
L:      643      169
D:      1      8

         Counters
         Bearer 0
SF:      145774      142846
SFErr:      20      3
RS:      3115940      2570288
RSCorr:      9258      204
RSUnCorr:   20      0

ReXmt:      11049      0
ReXmtCorr:   11048      0
ReXmtUnCorr:   21      0

         Bearer 0
HEC:      21      9
OCD:      0      0
LCD:      0      0
Total Cells:   13012448      3005373
Data Cells:   235369      82893
Drop Cells:   0
Bit Errors:   1448      164

ES:      6595      721
SES:      113      0
UAS:      524      430
AS:      2345

         Bearer 0
INP:      26.00      2.50
INPRein:   0.00      0.00
delay:      8      7
PER:      15.95      16.40
OR:      28.57      8.77
AgR:      2380.51   550.93

Bitswap:   532/557      2/2

Total time = 58 days 18 hours 11 min 44 sec
FEC:      1385583      370765
CRC:      14238      1102
ES:      6595      721
SES:      113      0
UAS:      524      430
LOS:      6      0
LOF:      27      0
LOM:      32      0
Latest 15 minutes time = 11 min 44 sec
FEC:      2736      52
CRC:      4      0
ES:      4      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:      3599      132
CRC:      8      3
ES:      8      2
SES:      0      0
UAS:      0      0
LOS:      0      0
LOF:      0      0
LOM:      0      0
Latest 1 day time = 18 hours 11 min 44 sec
FEC:      353952      2108
CRC:      6496      3
ES:      4332      2
SES:      0      0
UAS:      59      59
LOS:      0      0
LOF:      0      0
LOM:      0      0
Previous 1 day time = 24 hours 0 sec
FEC:      203696      2718
CRC:      369      3
ES:      359      3
SES:      0      0
UAS:      0      0
LOS:      0      0
LOF:      0      0
LOM:      0      0
Since Link time = 39 min 3 sec
FEC:      9258      204
CRC:      20      3
ES:      20      2
SES:      0      0
UAS:      0      0
LOS:      0      0
LOF:      0      0
LOM:      0      0
NTR: mipsCntAtNtr=0 ncoCntAtNtr=0


The current attenuation figures are : 65.5 dB downstream ; 41.9 dB upstream. Notice how much they have increased (worsened) since the time when the previous stats were captured: 65.0 dB ; 41.6 dB
« Last Edit: August 24, 2020, 03:46:16 PM by Weaver »
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burakkucat

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Re: Odd-shaped SNR-vs-tone graph - line #2 now
« Reply #3 on: August 24, 2020, 04:05:16 PM »

I would normally ignore a 0.3 - 0.5 dB change in relative values. But in your case, at the extreme limits of the technology, they have to be acknowledged.

  :wall:  I'll do it for you . . .
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Weaver

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Re: Odd-shaped SNR-vs-tone graph - line #2 now
« Reply #4 on: August 25, 2020, 09:46:26 AM »

How can I find the current FTR ? (Or MSR of course) Where should I look?
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burakkucat

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Re: Odd-shaped SNR-vs-tone graph - line #2 now
« Reply #5 on: August 25, 2020, 05:08:54 PM »

I wonder if A&A have the means to query the BTW systems for those values?  :-\

[Edited to insert a missing word.]
« Last Edit: August 25, 2020, 05:52:27 PM by burakkucat »
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Weaver

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Re: Odd-shaped SNR-vs-tone graph - line #2 now
« Reply #6 on: August 25, 2020, 05:36:53 PM »

Thank you for jogging my memory! I suddenly thought where I might so find it given. A&A’s remote query "Sync Status" is a function that is available in the control server clueless.aa.net.uk and it reports the following today for line 2:

BT Test xDSL Status Check:Pass Standalone sub test passed successfully.Pass OK. Circuit In Sync
BRAS=2083kb/s FTR=2278kb/s MSR=2848kb/s ServOpt=1 I/L=I
A SERVICE OPTION CHANGE ORDER IS IN PROGRESS ON THIS LINE
Up Sync=544kb/s LoopLoss=41.9dB SNR=6.1dB ErrSec=0 HECErr=0 Cells=0
Down Sync=2362kb/s LoopLoss=65.5dB SNR=3.1dB ErrSec=0 HECErr=N/A Cells=0


And for line 4:

BT Test xDSL Status Check:Pass Standalone sub test passed successfully.Pass OK. Circuit In Sync
BRAS=2498kb/s FTR=2278kb/s MSR=2848kb/s ServOpt=1 I/L=I
A SERVICE OPTION CHANGE ORDER IS IN PROGRESS ON THIS LINE
Up Sync=550kb/s LoopLoss=41.7dB SNR=6.1dB ErrSec=0 HECErr=0 Cells=0
Down Sync=2832kb/s LoopLoss=65dB SNR=2.4dB ErrSec=0 HECErr=N/A Cells=0


I wish I knew exactly what the definition is. Does it mean that you have to have a downstream target SNRM of 6dB ? Because without some standard then it’s wildly variable of course. This downstream sync rate in both cases is with a target SNRM of 3dB.
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burakkucat

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Re: Odd-shaped SNR-vs-tone graph - line #2 now
« Reply #7 on: August 25, 2020, 05:56:38 PM »

I suspect that a target SNRM of 6 dB is used to provide "base line values".
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Weaver

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Re: Odd-shaped SNR-vs-tone graph - line #2 now
« Reply #8 on: September 12, 2020, 05:21:47 PM »

The state of the lines now is - Live sync rates:
  #1: down 2730 kbps, up 519 kbps
  #2: down 2409 kbps, up 512 kbps
  #3: down 2927 kbps, up 376 kbps
  #4: down 2310 kbps, up 553 kbps
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