Forum Discussion

ljt1984's avatar
ljt1984
On our wavelength
2 days ago

Packet loss and profile changes

Hi,

I've recently came back to VM (October) and my connection has not been quite right from the off.

Intermittent packet loss which is now more frequent. I've reset the hub a couple of times, and it resolves for a day or so, then back to its old self. I've noticed since the last reset (this morning) that on the router log there seems to be a constant stream of upstream profile changes (Around once every 5 minutes). 

I've set up a BQM again this afternoon and here is the graph so far - 


Hopefully one of the VM forum techs will see this and hopefully shed some light or help get it resolved please.

I will post my line stats in the next post.

9 Replies

  • ljt1984's avatar
    ljt1984
    On our wavelength

    3.0 Downstream channels

    Channel    Frequency (Hz)    Power (dBmV)    SNR (dB)    Modulation    Channel ID
    1    139000000    8.5    40    QAM 256    1
    2    147000000    8.1    40    QAM 256    2
    3    155000000    7.7    40    QAM 256    3
    4    163000000    7.4    40    QAM 256    4
    5    171000000    7.2    40    QAM 256    5
    6    179000000    7.1    40    QAM 256    6
    7    187000000    6.9    40    QAM 256    7
    8    195000000    6.9    40    QAM 256    8
    9    203000000    6.6    40    QAM 256    9
    10    211000000    6.5    40    QAM 256    10
    11    219000000    6.5    39    QAM 256    11
    12    227000000    6.4    40    QAM 256    12
    13    235000000    6.4    40    QAM 256    13
    14    243000000    6.3    40    QAM 256    14
    15    251000000    6.1    40    QAM 256    15
    16    259000000    5.9    40    QAM 256    16
    17    267000000    5.8    40    QAM 256    17
    18    275000000    5.9    40    QAM 256    18
    19    283000000    6.3    40    QAM 256    19
    20    291000000    6.8    40    QAM 256    20
    21    299000000    7.1    40    QAM 256    21
    22    347000000    8    40    QAM 256    27
    23    355000000    8    40    QAM 256    28
    24    363000000    7.9    40    QAM 256    29
    25    371000000    7.9    41    QAM 256    30
    26    379000000    7.8    41    QAM 256    31
    27    387000000    7.6    40    QAM 256    32
    28    395000000    7.4    40    QAM 256    33
    29    403000000    7.1    40    QAM 256    34
    30    411000000    6.9    40    QAM 256    35
    31    419000000    6.8    40    QAM 256    36
    3.0 Downstream channels

    Channel    Locked Status    RxMER (dB)    Pre RS Errors    Post RS Errors
    1    Locked    40    6    0
    2    Locked    40    13    0
    3    Locked    40    6    0
    4    Locked    40    15    0
    5    Locked    40    10    0
    6    Locked    40    6    0
    7    Locked    40    9    0
    8    Locked    40    9    0
    9    Locked    40    6    0
    10    Locked    40    3    0
    11    Locked    39    7    0
    12    Locked    40    5    0
    13    Locked    40    7    0
    14    Locked    40    4    0
    15    Locked    40    2    0
    16    Locked    40    12    0
    17    Locked    40    4    0
    18    Locked    40    7    0
    19    Locked    40    3    0
    20    Locked    40    3    0
    21    Locked    40    4    0
    22    Locked    40    2    0
    23    Locked    40    2    0
    24    Locked    40    3    0
    25    Locked    41    3    0
    26    Locked    41    3    0
    27    Locked    40    9    0
    28    Locked    40    8    0
    29    Locked    40    7    0
    30    Locked    40    6    0
    31    Locked    40    4    0
    3.1 Downstream channels

    Channel    Channel Width (MHz)    FFT Type    Number of Active Subcarriers    Modulation (Active Profile)    First Active Subcarrier (Hz)
    37    94    4K    1840    QAM 4096    1108
    3.1 Downstream channels

    Channel ID    Locked Status    RxMER Data (dB)    PLC Power (dBmV)    Corrected errors (Active Profile)    Uncorrectable errors (Active Profile)
    37    Locked    0    5.0    1028317819    0

    3.0 Upstream channels

    Channel    Frequency (Hz)    Power (dBmV)    Symbol Rate (ksps)    Modulation    Channel ID
    0    49600000    44.3    5120    QAM 64    1
    1    43100000    44    5120    QAM 64    2
    2    36600000    44    5120    QAM 64    3
    3    30100000    43.8    5120    QAM 64    4
    4    23600000    43.3    5120    QAM 64    9
    3.0 Upstream channels

    Channel    Channel Type    T1 Timeouts    T2 Timeouts    T3 Timeouts    T4 Timeouts
    0    ATDMA    0    0    0    0
    1    ATDMA    0    0    1    0
    2    ATDMA    0    0    0    0
    3    ATDMA    0    0    0    0
    4    ATDMA    0    0    0    0
    3.1 Upstream channels

    Channel    Channel Width (MHz)    Power (dBmV)    FFT Type    Modulation
    10    10.4    39.5    2K    QAM 256
    3.1 Upstream channels

    Channel    Channel Type    Number of Active Subcarriers    First Active Subcarrier (Hz)    T3 Timeouts    T4 Timeouts
    10    OFDMA    208    74000000    0    0

    Network Log

    Time    Priority    Description
    17-11-2025 20:26:08    notice    GUI Login Status - Login Success from LAN interface
    17-11-2025 20:19:29    notice    US profile assignment change. US Chan ID: 10; Previous Profile: 12 13; New Profile: 11 13.;CM-MAC=2c:fb:0f:75:b3:1d;CMTS-MAC=00:01:5c:6d:88:50;CM-QOS=1.1;CM-VER=3.1;
    17-11-2025 20:14:26    notice    US profile assignment change. US Chan ID: 10; Previous Profile: 11 13; New Profile: 12 13.;CM-MAC=2c:fb:0f:75:b3:1d;CMTS-MAC=00:01:5c:6d:88:50;CM-QOS=1.1;CM-VER=3.1;
    17-11-2025 20:02:37    notice    US profile assignment change. US Chan ID: 10; Previous Profile: 12 13; New Profile: 11 13.;CM-MAC=2c:fb:0f:75:b3:1d;CMTS-MAC=00:01:5c:6d:88:50;CM-QOS=1.1;CM-VER=3.1;
    17-11-2025 19:57:33    notice    US profile assignment change. US Chan ID: 10; Previous Profile: 11 13; New Profile: 12 13.;CM-MAC=2c:fb:0f:75:b3:1d;CMTS-MAC=00:01:5c:6d:88:50;CM-QOS=1.1;CM-VER=3.1;
    17-11-2025 19:55:59    notice    US profile assignment change. US Chan ID: 10; Previous Profile: 12 13; New Profile: 11 13.;CM-MAC=2c:fb:0f:75:b3:1d;CMTS-MAC=00:01:5c:6d:88:50;CM-QOS=1.1;CM-VER=3.1;
    17-11-2025 19:50:56    notice    US profile assignment change. US Chan ID: 10; Previous Profile: 11 13; New Profile: 12 13.;CM-MAC=2c:fb:0f:75:b3:1d;CMTS-MAC=00:01:5c:6d:88:50;CM-QOS=1.1;CM-VER=3.1;
    17-11-2025 19:34:10    notice    US profile assignment change. US Chan ID: 10; Previous Profile: 12 13; New Profile: 11 13.;CM-MAC=2c:fb:0f:75:b3:1d;CMTS-MAC=00:01:5c:6d:88:50;CM-QOS=1.1;CM-VER=3.1;
    17-11-2025 19:29:07    notice    US profile assignment change. US Chan ID: 10; Previous Profile: 11 13; New Profile: 12 13.;CM-MAC=2c:fb:0f:75:b3:1d;CMTS-MAC=00:01:5c:6d:88:50;CM-QOS=1.1;CM-VER=3.1;
    17-11-2025 19:15:44    notice    US profile assignment change. US Chan ID: 10; Previous Profile: 12 13; New Profile: 11 13.;CM-MAC=2c:fb:0f:75:b3:1d;CMTS-MAC=00:01:5c:6d:88:50;CM-QOS=1.1;CM-VER=3.1;
    17-11-2025 19:10:41    notice    US profile assignment change. US Chan ID: 10; Previous Profile: 11 13; New Profile: 12 13.;CM-MAC=2c:fb:0f:75:b3:1d;CMTS-MAC=00:01:5c:6d:88:50;CM-QOS=1.1;CM-VER=3.1;
    17-11-2025 18:54:03    notice    US profile assignment change. US Chan ID: 10; Previous Profile: 12 13; New Profile: 11 13.;CM-MAC=2c:fb:0f:75:b3:1d;CMTS-MAC=00:01:5c:6d:88:50;CM-QOS=1.1;CM-VER=3.1;
    17-11-2025 18:48:59    notice    US profile assignment change. US Chan ID: 10; Previous Profile: 11 13; New Profile: 12 13.;CM-MAC=2c:fb:0f:75:b3:1d;CMTS-MAC=00:01:5c:6d:88:50;CM-QOS=1.1;CM-VER=3.1;
    17-11-2025 18:47:35    notice    US profile assignment change. US Chan ID: 10; Previous Profile: 12 13; New Profile: 11 13.;CM-MAC=2c:fb:0f:75:b3:1d;CMTS-MAC=00:01:5c:6d:88:50;CM-QOS=1.1;CM-VER=3.1;
    17-11-2025 18:42:31    notice    US profile assignment change. US Chan ID: 10; Previous Profile: 11 13; New Profile: 12 13.;CM-MAC=2c:fb:0f:75:b3:1d;CMTS-MAC=00:01:5c:6d:88:50;CM-QOS=1.1;CM-VER=3.1;
    17-11-2025 18:42:03    notice    US profile assignment change. US Chan ID: 10; Previous Profile: 12 13; New Profile: 11 13.;CM-MAC=2c:fb:0f:75:b3:1d;CMTS-MAC=00:01:5c:6d:88:50;CM-QOS=1.1;CM-VER=3.1;
    17-11-2025 18:37:00    notice    US profile assignment change. US Chan ID: 10; Previous Profile: 11 13; New Profile: 12 13.;CM-MAC=2c:fb:0f:75:b3:1d;CMTS-MAC=00:01:5c:6d:88:50;CM-QOS=1.1;CM-VER=3.1;
    17-11-2025 18:28:43    notice    GUI Login Status - Login Success from LAN interface
    17-11-2025 18:26:38    notice    US profile assignment change. US Chan ID: 10; Previous Profile: 12 13; New Profile: 11 13.;CM-MAC=2c:fb:0f:75:b3:1d;CMTS-MAC=00:01:5c:6d:88:50;CM-QOS=1.1;CM-VER=3.1;
    17-11-2025 18:22:01    notice    GUI Login Status - Login Success from LAN interface
    17-11-2025 18:21:35    notice    US profile assignment change. US Chan ID: 10; Previous Profile: 11 13; New Profile: 12 13.;CM-MAC=2c:fb:0f:75:b3:1d;CMTS-MAC=00:01:5c:6d:88:50;CM-QOS=1.1;CM-VER=3.1;
    17-11-2025 18:15:08    notice    US profile assignment change. US Chan ID: 10; Previous Profile: 12 13; New Profile: 11 13.;CM-MAC=2c:fb:0f:75:b3:1d;CMTS-MAC=00:01:5c:6d:88:50;CM-QOS=1.1;CM-VER=3.1;
    17-11-2025 18:10:05    notice    US profile assignment change. US Chan ID: 10; Previous Profile: 11 13; New Profile: 12 13.;CM-MAC=2c:fb:0f:75:b3:1d;CMTS-MAC=00:01:5c:6d:88:50;CM-QOS=1.1;CM-VER=3.1;
    17-11-2025 18:02:21    notice    US profile assignment change. US Chan ID: 10; Previous Profile: 12 13; New Profile: 11 13.;CM-MAC=2c:fb:0f:75:b3:1d;CMTS-MAC=00:01:5c:6d:88:50;CM-QOS=1.1;CM-VER=3.1;
    17-11-2025 17:57:18    notice    US profile assignment change. US Chan ID: 10; Previous Profile: 11 13; New Profile: 12 13.;CM-MAC=2c:fb:0f:75:b3:1d;CMTS-MAC=00:01:5c:6d:88:50;CM-QOS=1.1;CM-VER=3.1;
    17-11-2025 17:56:02    notice    US profile assignment change. US Chan ID: 10; Previous Profile: 12 13; New Profile: 11 13.;CM-MAC=2c:fb:0f:75:b3:1d;CMTS-MAC=00:01:5c:6d:88:50;CM-QOS=1.1;CM-VER=3.1;
    17-11-2025 17:50:58    notice    US profile assignment change. US Chan ID: 10; Previous Profile: 11 13; New Profile: 12 13.;CM-MAC=2c:fb:0f:75:b3:1d;CMTS-MAC=00:01:5c:6d:88:50;CM-QOS=1.1;CM-VER=3.1;
    17-11-2025 17:49:55    notice    GUI Login Status - Login Success from LAN interface
    17-11-2025 17:49:41    notice    US profile assignment change. US Chan ID: 10; Previous Profile: 12 13; New Profile: 11 13.;CM-MAC=2c:fb:0f:75:b3:1d;CMTS-MAC=00:01:5c:6d:88:50;CM-QOS=1.1;CM-VER=3.1;
    17-11-2025 17:44:38    notice    US profile assignment change. US Chan ID: 10; Previous Profile: 11 13; New Profile: 12 13.;CM-MAC=2c:fb:0f:75:b3:1d;CMTS-MAC=00:01:5c:6d:88:50;CM-QOS=1.1;CM-VER=3.1;
    17-11-2025 17:42:35    notice    US profile assignment change. US Chan ID: 10; Previous Profile: 12 13; New Profile: 11 13.;CM-MAC=2c:fb:0f:75:b3:1d;CMTS-MAC=00:01:5c:6d:88:50;CM-QOS=1.1;CM-VER=3.1;
    17-11-2025 17:37:32    notice    US profile assignment change. US Chan ID: 10; Previous Profile: 11 13; New Profile: 12 13.;CM-MAC=2c:fb:0f:75:b3:1d;CMTS-MAC=00:01:5c:6d:88:50;CM-QOS=1.1;CM-VER=3.1;
    17-11-2025 17:19:50    notice    US profile assignment change. US Chan ID: 10; Previous Profile: 12 13; New Profile: 11 13.;CM-MAC=2c:fb:0f:75:b3:1d;CMTS-MAC=00:01:5c:6d:88:50;CM-QOS=1.1;CM-VER=3.1;
    17-11-2025 17:14:46    notice    US profile assignment change. US Chan ID: 10; Previous Profile: 11 13; New Profile: 12 13.;CM-MAC=2c:fb:0f:75:b3:1d;CMTS-MAC=00:01:5c:6d:88:50;CM-QOS=1.1;CM-VER=3.1;
    17-11-2025 17:13:35    notice    US profile assignment change. US Chan ID: 10; Previous Profile: 12 13; New Profile: 11 13.;CM-MAC=2c:fb:0f:75:b3:1d;CMTS-MAC=00:01:5c:6d:88:50;CM-QOS=1.1;CM-VER=3.1;
    17-11-2025 17:08:31    notice    US profile assignment change. US Chan ID: 10; Previous Profile: 11 13; New Profile: 12 13.;CM-MAC=2c:fb:0f:75:b3:1d;CMTS-MAC=00:01:5c:6d:88:50;CM-QOS=1.1;CM-VER=3.1;

  • legacy1's avatar
    legacy1
    Alessandro Volta

     don't look that good is the hub in modem mode or router mode?

    run cmd on wired PC

    ping -n 200 194.168.4.100

    to see if packet loss still shows 

    • ljt1984's avatar
      ljt1984
      On our wavelength

      Hi

      It's in router mode. 

      The ping result was 2 lost packets (1%) which seems to corresponds to the BQM readings 

  • Adduxi's avatar
    Adduxi
    Very Insightful Person

    Looks like the 3.1 Upstream channel 10 has issues, possibly noise, that necessitates changing profiles to cope? 

    • legacy1's avatar
      legacy1
      Alessandro Volta

      look that way but like shouldn't the hub detect a problem and use the other 3.0 upstream channel? it like the packet gets put on the 3.1 channel and then drops it instead of the moving the packet to a 3.0 channel.  Or could it be the case the packet is sent on the 3.1 channel and is corrupted which the gateway change hub profile for better stability then the gateway thinks all is fine to change profile back to better speed then the whole thing start over again? but shouldn't the system see this and not flap the channel?  

      • gitty's avatar
        gitty
        On our wavelength

        Technically, the modem doesn't know about upstream noise. The CMTS sees an issue and assigns a new profile, to prevent packet loss - or at least an attempt to prevent it. We cannot know for sure where the loss is happening. There may be loss in the 3.0 upstream.

        From a noise issue occur in the 3.1 upstream to the new profile has been assigned, the CMTS may schedule new transmissions using profile 13, which is always assigned (the profile with most robust modulation), or use the 3.0 upstream. It's up to the CMTS what happens.

  • ljt1984's avatar
    ljt1984
    On our wavelength

    Just for information I've now updated the BQM for the last 24 hours. The large packet loss on the graph was me rebooting the Hub 5 again just on the slim hope it might help resolve the issue!


    I did have a look at the connection in the brown box and it did look badly corroded to me, but it was dark and I couldn't get a decent picture, so will have to wait until I can get a picture in daylight.

  • ljt1984's avatar
    ljt1984
    On our wavelength

    Not sure why but I've tried posting replies and they dont seem to show up?

    Anyway I've had a look at the connection in the brown box and to me it looks really corroded but it was too dark when I got in from work to take a decent photo, so will try again in better light.