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VesselCottonDes's avatar
VesselCottonDes
Tuning in
2 months ago

Intermittent very brief connection drops

Hello,

I've been experiencing (usually very) brief connection loss intermittently for a couple of years now. After the 4th tech visit in 2023, and the subsequent CM self-installed replacement with a SuperHub 5 things were improved. My feeling was, and still is, that this later CM mostly masked/flattered the overall ongoing issue.

I'm reporting this now as I just won't get around to it otherwise and it'll continue to annoy me. It's been a case of it working well enough most of the time for me not to feel able to summon the mental strength to report it (LOL).

The timeline below is more cathartic for me than anything else. No, I didn't really want to be collating this stuff, but there we are.

Yesterday, whilst at home, I experienced about 7 drops, and added to the past week's drops, I'd had enough, so started pulling together what info I have.

Unprompted by me, I was then texted by VM yesterday to read my email re: "broadband connection may be being slow or sometimes disconnecting". I didn't receive one (and I have checked my spam folder, etc.) I assumed this was to suggest power cycling the CM, so did that. Unfortunately, no change following this.

The service status page at that point was coming back with "Intermittent signal in your area" (and it's the same today - now).

I appreciate this will probably yield a tech in the first instance, but for the record, I'm prepared to bet that the cabling from the pit/grid up and into the back of the CM is fine.

The reason I have the records below is my habit to quickly grab the CM logs/levels (using my phone) each time I experience a drop.

Please can you assist?

Thanks,
Jon.

---

16/08/2023 - Likely posting BQM screenshots on VM Community

19/08/2023 - VM tech - visit 1

23/08/2023 - Continued to post about ongoing intermittent drops on VM Community (couldn't face the phone lines)

07/09/2023 - VM tech - visit 2 - new CM, split cable fixed and external brown box replaced, subsequently no packet loss from grid into house

03/10/2023 - VM senior tech - visit 3 - no problems with levels, Sam Knows(?) showing 137 drops this week

04/10/2023 - Tap bank replaced by networks

06/10/2023 - Several connection drop-offs - still similar to before

19/10/2023 - VM tech - visit 4 - CM PSU replaced, fresh cable between isolator and CM (and positioned well away from other electrics). Constellation check came back fine with no observable problems with wiring from pit/path into back of CM.

26/10/2023 - VM ordered new CM

02/11/2023 - SuperHub 5 self-install

14/11/2023 - Returned old CM

17-11-2023 00:09:26    critical    No Ranging Response received - T3 time-out;CM-
17-11-2023 00:09:26    critical    16 consecutive T3 timeouts while trying to range on upstream channel :9b:b0;CMTS-MAC=00:9e:1e:58:2e:b4;CM-QOS=1.1;CM-VER=3.1;
17-11-2023 00:08:46    critical    No Ranging Response received - T3 time-out;CM-;CM-QOS=1.1;CM-VER=3.1;
16-11-2023 23:46:32    notice    US profile assignment change. US Chan ID: 6; Previous Profile: 11 13; New Profile: 12 13.;CM-MAC=a4:22:49:ed:9b:b0;CMTS-MAC=
16-11-2023 23:46:32    warning    DBC-REQ Mismatch Between Calculated Value for P1.6hi Compared to CCAP Provided Value;CM-MAC=a

17-11-2023 02:43:37    critical    16 consecutive T3 timeouts while trying to range on upstream channel 
17-11-2023 02:43:17    critical    Started Unicast Maintenance Ranging - No Response received - T3 time-

03-12-2023 18:22:05    critical    16 consecutive T3 timeouts while trying to range on upstream channel 

---

30-01-2024 04:01:49    warning    RNG-RSP CCAP Commanded Power Exceeds Value Corresponding to the Top of the DRW;CM-MAC=

01-02-2024 12:18:10    critical    16 consecutive T3 timeouts while trying to range on upstream channel 

07-02-2024 01:38:45    critical    No Ranging Response received - T3 time-out;CM-

23-02-2024 11:57:09    critical    Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-
23-02-2024 11:53:53    critical    Started Unicast Maintenance Ranging - No Response received - T3 time-

17-03-2024 13:02:53    critical    No Ranging Response received - T3 time-out;CM-

08-04-2024 21:08:27    warning        ToD request sent - No Response received;CM-
08-04-2024 21:06:46    critical    Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=a
08-04-2024 10:23:44    critical    No Ranging Response received - T3 time-out;CM-
08-04-2024 10:23:43    critical    Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC
08-04-2024 10:20:28    critical    Started Unicast Maintenance Ranging - No Response received - T3 

09-05-2024 13:12:49    critical    Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=a
08-05-2024 20:49:05    warning    DBC-REQ Mismatch Between Calculated Value for P1.6hi Compared to CCAP Provided Value;CM-MACQOS=1.1;CM-VER=3.1;
08-05-2024 20:49:05    notice    US profile assignment change. US Chan ID: 6; Previous Profile: 12 13; New Profile: 11 13.;CM-MAC=a4:2
08-05-2024 19:48:23    notice    US profile assignment change. US Chan ID: 6; Previous Profile: 11 13; New Profile: 12 13.;CM-MA
08-05-2024 19:48:23    warning    DBC-REQ Mismatch Between Calculated Value for P1.6hi Compared 
07-05-2024 10:14:03    critical    Started Unicast Maintenance Ranging - No Response received - T3 time-

15-06-2024 19:55:23    critical    Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=aCM-QOS=1.1;CM-VER=3.1;
15-06-2024 00:19:18    error    DHCP RENEW WARNING - Field invalid in response v4 option;CM-MAC
14-06-2024 19:08:31    notice    CM-STATUS message sent. Event Type Code: 24; Chan ID: 159; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 3.;CM-MAC=a
14-06-2024 19:06:38    notice    CM-STATUS message sent. Event Type Code: 16; Chan ID: 159; DSID: 
14-06-2024 18:18:42    notice    CM-STATUS message sent. Event Type Code: 24; Chan ID: 159; DSID: 
14-06-2024 18:16:45    notice    CM-STATUS message sent. Event Type Code: 16; Chan ID: 159; DSID: 
14-06-2024 11:53:24    critical    Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM
14-06-2024 11:50:08    critical    Started Unicast Maintenance Ranging - No Response received - T3 time-

26-06-2024 14:19:54    critical    Started Unicast Maintenance Ranging - No Response received - T3 time-
26-06-2024 14:19:50    critical    No Ranging Response received - T3 time-out;CM-

27-07-2024 22:28:29    critical    Started Unicast Maintenance Ranging - No Response received - T3 time-

11-09-2024 17:08:11    critical    Started Unicast Maintenance Ranging - No Response received - T3 time-

15-12-2024 08:22:46    critical    16 consecutive T3 timeouts while trying to range on upstream channel 

17-12-2024 08:31:07    critical    16 consecutive T3 timeouts while trying to range on upstream channel 

---

11/08/2025 Brownout in the house late evening - nothing stopped completely, but lights did flicker

12/08/2025 Moved external(/CM?) IP address - middle of day 2.50pm-ish - no obvious spikes of dropped packets in BQM prior to this date

11-09-2025 15:56:18    critical    16 consecutive T3 timeouts while trying to range on upstream channel 1;CM-MAC=a4:22:49:ed:9b:b0;CMTS-MAC=00:9e:1e:58:2e:b4;CM-QOS=1.1;CM-VER=3.1;
VM status page saying something like "an intermittent signal issue today"

22/09/2025 Evidently motivated to re-visit ThinkBroadband BQM to see what was occurring (I didn't note any levels at this point). Noticed the CM IP change and thus set up a new BQM to monitor from this point.

23-09-2025 18:57:21    critical    Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=
23-09-2025 18:57:06    critical    16 consecutive T3 timeouts while trying to range on upstream channel 8;CM-MAC
23-09-2025 18:57:06    critical    Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=
23-09-2025 18:57:05    critical    Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=
23-09-2025 18:57:04    notice    CM-STATUS message sent. Event Type Code: 5; Chan ID: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MQOS=
23-09-2025 18:57:01    critical    Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-0;CMTS-MAC=0    error    DBC-ACK not received;CM-MAC=a4
23-09-2025 18:56:46    critical    16 consecutive T3 timeouts while trying to range on upstream channel 1;CM-MA
23-09-2025 18:56:46    critical    Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-

24-09-2025 23:32:35    critical    Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=M-QOS=1.1;CM-VER=3.1;
24-09-2025 23:32:21    critical    Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC
24-09-2025 23:32:21    critical    16 consecutive T3 timeouts while trying to range on upstream channel 
24-09-2025 23:32:15    critical    Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-

25-09-2025 18:01:42    notice    CM-STATUS message sent. Event Type Code: 2; Chan ID: 25 27 28 32; 
25-09-2025 18:01:34    critical    No Ranging Response received - T3 time-out;CM-
25-09-2025 18:01:33    warning    DBC-REQ Mismatch Between Calculated Value for P1.6hi Compared to CCAP Provided Value;CM
25-09-2025 18:01:32    critical    SYNC Timing Synchronization failure - Loss of Sync;CM-

29-09-2025 23:41:58    warning    DBC-REQ Mismatch Between Calculated Value for P1.6hi Compared QOS=1.1;CM-VER=3.1;
29-09-2025 23:41:47    critical    Started Unicast Maintenance Ranging - No Response received - T3 

02-10-2025 14:18:10    critical    16 consecutive T3 timeouts while trying to range on upstream channel 
02-10-2025 14:18:05    critical    Started Unicast Maintenance Ranging - No Response received - T3 time-

09-10-2025 16:23:26    critical    16 consecutive T3 timeouts while trying to range on upstream channel 

10-10-2025 16:49:44    critical    16 consecutive T3 timeouts while trying to range on upstream channel 

10-10-2025 16:50:28    critical    16 consecutive T3 timeouts while trying to range on upstream channel 

 

[Mod - MAC addresses removed]

3 Replies

  • Ayisha_B's avatar
    Ayisha_B
    Icon for Forum Team rankForum Team
    2 months ago

    Hi VesselCottonDes 👋,

    Welcome back to our Community Forums and thanks for your post.

    I am sorry to hear about the issues with your service and would love to assist you.

    Our system has detected a slow speed/intermittent connection issue with your broadband, and we have contacted you proactively via email regarding this.

    The latest email you should have received contains guidance on how to check & tighten your cables and connections around the home, as well as how to reset the Hub. These steps are easy to follow and often resolve issues like this, however I appreciate you've stated you did not receive this.

    Could you therefore check all the white cables are connected securely to the Hub, any TV boxes, splitters and the wall socket. Once done reboot your Hub. 

    If you find the issue persists once you have done this, then please respond to my PM and we can go from there 😊

  • VesselCottonDes's avatar
    VesselCottonDes
    Tuning in
    2 months ago

    Hi Ayisha_B,

    I've just re-read this. Given that I didn't receive the advice emails, are you asking me to do a pinhole reset on the CM? Or just a power cycle at the wall? All cables and connections are tight - nothing has changed/moved since the last tech visit in 2023. I last restarted the CM probably Thursday/Friday last week - that doesn't resolve things - for instance, I still had multiple brief drops yesterday.

    Thanks.  

  • VesselCottonDes's avatar
    VesselCottonDes
    Tuning in
    2 months ago

     

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    9    203000000    8.4    41    QAM 256    9
    10    211000000    8.6    41    QAM 256    10
    11    219000000    8.4    41    QAM 256    11
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    13    235000000    8.2    41    QAM 256    13
    14    243000000    7.9    41    QAM 256    14
    15    251000000    7.7    41    QAM 256    15
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    27    347000000    8.4    42    QAM 256    27
    28    355000000    8.1    42    QAM 256    28
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    30    371000000    7.9    42    QAM 256    30
    31    379000000    8    42    QAM 256    31
    32    387000000    8    42    QAM 256    32
    3.0 Downstream channels

    Channel    Locked Status    RxMER (dB)    Pre RS Errors    Post RS Errors
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    2    Locked    41    5084    22264
    3    Locked    41    5536    23331
    4    Locked    41    5254    22479
    5    Locked    41    4879    22641
    6    Locked    41    4909    23249
    7    Locked    41    4188    21629
    8    Locked    41    4544    22623
    9    Locked    41    4620    23179
    10    Locked    41    4418    22779
    11    Locked    41    4314    21319
    12    Locked    41    4809    21537
    13    Locked    41    4959    22213
    14    Locked    41    4844    21173
    15    Locked    41    5497    23138
    16    Locked    41    4622    23438
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    18    Locked    41    5084    23205
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    23    Locked    42    4969    22790
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    159    Locked    0    5.8    3987689513    114419
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    Channel    Frequency (Hz)    Power (dBmV)    Symbol Rate (ksps)    Modulation    Channel ID
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    6    OFDMA    200    74000000    239    0
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    Network access    Allowed
    Maximum Number of CPEs    3
    Baseline Privacy    Enabled
    DOCSIS Mode    3.1
    Config file    rkldJKDHSUBsgvca69834ncxv9873
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    [MOD EDIT: Private information removed]