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Crazy ADSL line stats graphs

Community Veteran
Posts: 4,969
Thanks: 362
Fixes: 16
Registered: 10-06-2010

Crazy ADSL line stats graphs

After a weekend of relative broadband stability, something happened at 06:12 this morning - I'm guessing it was the DLM reducing the DS target SNRM - which seems a strange thing to do considering the sync speed is still lower than what is was previously. And now the upstream noise margin is has the strange behaviour of smoothly oscillating up and down approximately every 30 minutes.
Stats at 18/10/2013 18:59:58
[tt]US Connection Rate:    882    DS Connection Rate:    3774
DS Line Attenuation:    58.4    DS Margin:              6.0
US Line Attenuation:    36.7    US Margin:              5.1[/tt]
Current stats
[tt]US Connection Rate:    882    DS Connection Rate:    3135
DS Line Attenuation:    57.0    DS Margin:              3.8
US Line Attenuation:    36.4    US Margin:              3.6[/tt]
7 REPLIES
Plusnet Alumni (retired) chrispurvey
Plusnet Alumni (retired)
Posts: 5,369
Fixes: 1
Registered: 13-07-2012

Re: Crazy ADSL line stats graphs

Checking over your connection ejs I can't see anything to cause a change.
Has anything changed internally recently?

Community Veteran
Posts: 4,969
Thanks: 362
Fixes: 16
Registered: 10-06-2010

Re: Crazy ADSL line stats graphs

I don't know of anything that's changed in the house recently, and I won't be doing any proper investigating until the weekend. Whatever knocked off a chunk of the line speed probably first appeared at about 16:35 on Fri 8th Nov, but I initially attributed that due to it getting dark combined with the DLM switching off interleaving earlier that day.
Stats with error counts since 06:12 yesterday (about 37.5 hours):
[tt]AR7 DSL Modem Statistics:
--------------------------------
[DSL Modem Stats]
        US Connection Rate:    882    DS Connection Rate:    3135
        DS Line Attenuation:    57.0    DS Margin:              3.5
        US Line Attenuation:    36.4    US Margin:              2.7
        US Payload :            82371696        DS Payload:            888417936
        US Superframe Cnt :    7975348 DS Superframe Cnt:      7975349
        US Transmit Power :    0      DS Transmit Power:      0
        LOS errors:            0      SEF errors:            0
        Errored Seconds:        92528  Severely Err Secs:      37754
        Frame mode:            0      Max Frame mode:        0
        Trained Path:          1      US Peak Cell Rate:      2080
        Trained Mode:          8      Selected Mode:          8
        ATUC Vendor Code:      54535443        ATUC Revision:  3
        Hybrid Selected:        3      Trellis:                1
        Showtime Count:        4      DS Max Attainable Bit Rate: 3388 kbps
        BitSwap:                1      US Max Attainable Bit Rate: 1069552 bps
        Annex:                  AnxA    psd_mask_qualifier: 0x0000
        Power Management Status: L0    DS HLINSC: 0
        US ACTPSD:              -345    DS ACTPSD: -366
        Total init. errors:    0      Total init. timeouts: 0
        Showtime init. errors:  0      Showtime init. timeouts: 0
        Last showtime init. errors: 0  Last showtime init. timeouts: 0
        ATUC ghsVid:  b5 00 54 53 54 43 05 10
        T1413Vid: 00 00        T1413Rev: 00            VendorRev: 00
        ATUR ghsVid:  b5 00 54 53 54 43 00 00
        T1413Vid: 00 00 T1413Rev: 00    VendorRev: 00
        [Upstream (TX) Interleave path]
        CRC:    566    FEC:    211276  NCD:    0
        LCD:    0      HEC:    606
        [Downstream (RX) Interleave path]
        CRC:    1560944 FEC:    679391411      NCD:    0
        LCD:    0      HEC:    3
        [Upstream (TX) Fast path]
        CRC:    0      FEC:    0      NCD:    0
        LCD:    0      HEC:    0
        [Downstream (RX) Fast path]
        CRC:    0      FEC:    0      NCD:    0
        LCD:    0      HEC:    0
[ATM Stats]
        [Upstream/TX]
        Good Cell Cnt:  1716077
        Idle Cell Cnt:  280317810
        Tx Packets Dropped Count:      0
        Tx Bad Packets Count:  10
        [Downstream/RX)]
        Good Cell Cnt:  18508707
        Idle Cell Cnt:  982603318
        Bad Hec Cell Cnt:      1405095
        Overflow Dropped Cell Cnt:      0
        Rx Packets Dropped Count:      0
        Rx Bad Packets Count:  0

[SAR AAL5 Stats]
        Tx PDU's:      4504113
        Rx PDU's:      7040481
        Tx Total Bytes: 368138286
        Rx Total Bytes: 805234652
        Tx Total Error Counts:  0
        Rx Total Error Counts:  30057
[/tt]
Community Veteran
Posts: 4,969
Thanks: 362
Fixes: 16
Registered: 10-06-2010

Re: Crazy ADSL line stats graphs

Well it gets even more odd - whatever was affecting the downstream appears to have disappeared at 21:00 today, but the weirdness on the upstream graph continues.
Community Veteran
Posts: 4,969
Thanks: 362
Fixes: 16
Registered: 10-06-2010

Re: Crazy ADSL line stats graphs

The line speed and weirdness of the upstream graphs seems to have returned to normal at 05:50 today.
Current stats:
[tt]US Connection Rate:    882    DS Connection Rate:    3690
DS Line Attenuation:    58.0    DS Margin:              6.1
US Line Attenuation:    36.4    US Margin:              5.2[/tt]
Superuser
Superuser
Posts: 10,324
Thanks: 1,847
Fixes: 19
Registered: 22-08-2007

Re: Crazy ADSL line stats graphs

The uniformity of this interference is very strange - 4 cycles an hour, uniform magnitude and nearly a perfect sine wave!  One for BTOR? At least asking them for a view..?
Community Veteran
Posts: 4,969
Thanks: 362
Fixes: 16
Registered: 10-06-2010

Re: Crazy ADSL line stats graphs

It seems to have disappeared just before 6am this morning - almost 48 hours after it started.
Superuser
Superuser
Posts: 10,324
Thanks: 1,847
Fixes: 19
Registered: 22-08-2007

Re: Crazy ADSL line stats graphs

One for the scrap book I think, under the category "strange unexplained things I've seen before!".  Crazy