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Annuity8524's avatar
Annuity8524
Joining in
12 months ago

SYNC Timing Synchronization failure - Cable Modem Reboot because of - kernel-panic

Recently my connection has become very unstable, dropouts happen multiple times a day, even multiple times an hour sometimes.

The logs show many reboots due to kernel panic. Rebooting doesn't seem to make any difference.

Any help would be greatly appreciated.

 

04-11-2024 15:11:30warningMDD message timeout;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
04-11-2024 15:11:19noticeREGISTRATION COMPLETE - Waiting for Operational status
04-11-2024 15:11:14warningRNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
04-11-2024 15:11:13warningRNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
04-11-2024 15:11:13warningDynamic Range Window violation
04-11-2024 15:11:08noticeDS profile assignment change. DS Chan ID: 32; Previous Profile: ; New Profile: 1 2 3.;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
04-11-2024 15:11:07noticeTLV-11 - unrecognized OID;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
04-11-2024 15:11:00warningDHCP WARNING - Non-critical field invalid in response ;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
04-11-2024 15:10:58noticeHonoring MDD; IP provisioning mode = IPv4
04-11-2024 15:10:52criticalNo Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
04-11-2024 15:10:46criticalSYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
04-11-2024 15:10:45criticalCable Modem Reboot because of - kernel-panic
04-11-2024 04:37:33criticalNo Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
04-11-2024 04:37:28criticalSYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
04-11-2024 04:37:27criticalCable Modem Reboot because of - kernel-panic
03-11-2024 21:30:19criticalNo Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
03-11-2024 21:30:13criticalSYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
03-11-2024 21:30:13criticalCable Modem Reboot because of - kernel-panic
03-11-2024 19:56:47criticalNo Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
03-11-2024 19:56:41criticalCable Modem Reboot because of - kernel-panic
03-11-2024 19:56:41criticalSYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
03-11-2024 18:58:15criticalNo Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
03-11-2024 18:58:09criticalSYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
03-11-2024 18:58:09criticalCable Modem Reboot because of - kernel-panic
03-11-2024 15:40:57criticalNo Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
03-11-2024 15:40:48criticalSYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
03-11-2024 15:40:42criticalNo Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
03-11-2024 15:40:38criticalSYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;

 

3.0 Downstream channels

Channel Frequency (Hz) Power (dBmV) SNR (dB) Modulation Channel ID
13310000007.741QAM 25625
21390000006.641QAM 2561
31470000006.242QAM 2562
41550000006.343QAM 2563
51630000006.643QAM 2564
61710000006.742QAM 2565
71790000006.942QAM 2566
8187000000742QAM 2567
91950000007.642QAM 2568
102110000007.742QAM 25610
112190000007.443QAM 25611
12227000000743QAM 25612
132350000007.143QAM 25613
142430000006.942QAM 25614
152510000006.841QAM 25615
162590000006.841QAM 25616
172670000006.841QAM 25617
182750000007.241QAM 25618
192830000007.741QAM 25619
202910000008.141QAM 25620
212990000008.543QAM 25621
223070000008.343QAM 25622
233150000008.443QAM 25623
24323000000842QAM 25624
253390000007.641QAM 25626
26347000000741QAM 25627
273550000006.540QAM 25628
28363000000641QAM 25629
293710000005.642QAM 25630
303790000005.343QAM 25631
313870000004.743QAM 25632

3.0 Downstream channels

Channel Locked Status RxMER (dB) Pre RS Errors Post RS Errors
1Locked4110
2Locked4100
3Locked4200
4Locked4300
5Locked4300
6Locked4200
7Locked4200
8Locked4200
9Locked4200
10Locked4200
11Locked4300
12Locked4300
13Locked4300
14Locked4200
15Locked4100
16Locked4100
17Locked4100
18Locked4100
19Locked4100
20Locked4110
21Locked4300
22Locked4300
23Locked4320
24Locked4200
25Locked4100
26Locked4120
27Locked4010
28Locked4140
29Locked4240
30Locked4330
31Locked4370

3.1 Downstream channels

Channel Channel Width (MHz) FFT Type Number of Active Subcarriers Modulation (Active Profile) First Active Subcarrier (Hz)
33944K1840QAM 40961108

3.1 Downstream channels

Channel ID Locked Status RxMER Data (dB) PLC Power (dBmV) Corrected errors (Active Profile) Uncorrectable errors (Active Profile)
33Locked20-29.6138471738474720

 

3.0 Upstream channels

Channel Frequency (Hz) Power (dBmV) Symbol Rate (ksps) Modulation Channel ID
04960000042.85120QAM 641
14310000041.85120QAM 642
23660000040.85120QAM 643
33010000039.85120QAM 644
42360000039.55120QAM 649

3.0 Upstream channels

Channel Channel Type T1 Timeouts T2 Timeouts T3 Timeouts T4 Timeouts
0ATDMA0000
1ATDMA0000
2ATDMA0000
3ATDMA0000
4ATDMA0010

3.1 Upstream channels

Channel Channel Width (MHz) Power (dBmV) FFT Type Modulation
1210.439.02KQAM 256

3.1 Upstream channels

Channel Channel Type Number of Active Subcarriers First Active Subcarrier (Hz) T3 Timeouts T4 Timeouts
12OFDMA2087400000000

 

 

5 Replies

  • Daniel_Et's avatar
    Daniel_Et
    Forum Team (Retired)
    12 months ago

    Hi Annuity8524 👋 Thank you for your post and welcome to the Virgin Media Community 😀

    We're sorry to hear about the problems you've been having 😔

    Just to confirm, are you experiencing the same problems on devices connected via WiFi and ethernet cable?

    Advice on how to fix internet problems can be found here.

    Please pop back to us at your earliest convenience.

    Regards,
    Daniel

  • Sephiroth's avatar
    Sephiroth
    Alessandro Volta
    12 months ago

    I'm not sure that the Forum Understood what you were saying.  So I'll put it as a one liner (in CAPITALS) and then add some context.

    THE OP IS SUFFERING MODEM REBOOTS DUE TO A "KERNEL PANIC" AS EVIDENCED IN THE LOGS.

    The hub runs under Linux and the "Kernel Panic" is a Linux message that describes something that the hub's kernel processes (for critical errors) cannot handle.  The cause of that could be anything, ranging from faulty hardware, faulty error handling code, dodgy signals from an external device.

    I've noticed that your Docsis 3.1 downstream is totally borked (see poer levels, SNR and uncorrected errors) and that could be the problem.  @FORUMTEAM

    • Annuity8524's avatar
      Annuity8524
      Joining in
      12 months ago

      Thank you for this.

      Virgin support have been absolutley clueless everytime I mention kernel panic to them, nobody even seems to understand what the kernel is.

      I am equally clueless about Docsis, do you think the best bet is to try and get an engineer out?

      • Kath_P's avatar
        Kath_P
        Icon for Forum Team rankForum Team
        12 months ago

        Hi Annuity8524, 

        Thanks for coming back to us on this one. Before we can arrange an engineer, we still need to go through the usual diagnostics. We've not been able to locate your account based on your forum credentials. We will need to confirm some information with you in order for us to proceed with checks. 

        I have sent you a direct message to allow us to do this with you in a private space. If you are using a PC/Laptop then you can just click on the little ✉ at the top right-hand side of the page to access your inbox. If you are on a mobile/tablet device then instead click on the little circle icon in the top right then select 'Messages'. 😊

        Thanks,

  • Sephiroth's avatar
    Sephiroth
    Alessandro Volta
    12 months ago

    If your downstream still shows this:

    3.1 Downstream channels

    Channel ID Locked Status RxMER Data (dB) PLC Power (dBmV) Corrected errors (Active Profile) Uncorrectable errors (Active Profile)
    33Locked20-29.6138471738474720

    with figures like I've highlighted in red, then your circuit is in trouble.

    A technician needs to attend and then report the anomalous downstream to Network Team if it's still present.  The Forum Team can arrange the visit if they accept what I've said.