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Nednats's avatar
Nednats
Dialled in
2 months ago

Hub 5 stuck on DOCSIS 3.0 – Ranging Failures, High Upstream Power, DOCSIS 3.1 Not Engaging

I’m having ongoing issues with my Virgin Media Gig1 connection. Although I’m using a Hub 5, the modem consistently fails to register on DOCSIS 3.1 and falls back to DOCSIS 3.0 after rebooting. This is accompanied by performance instability, occasional packet loss, and errors in the modem logs.

I’ve already:

  • Had the Hub reprovisioned by VM support,
  • Performed full pinhole resets and reboots,
  • Eliminated internal factors (tested with a single device on Ethernet, no VLANs or custom networking),
  • Checked that all coaxial cabling and splitters are secure.

Despite this, the issue persists — and support continues to send boilerplate instructions or suggest a Hub swap, neither of which addresses the real cause.

 

Symptoms:

  • Upstream transmit power: consistently at ~52 dBmV
  • DOCSIS 3.1 channels: detected but not fully locking
  • Repeated modem log entries including:
    • RNG-RSP CCAP Commanded Power in Excess of 6 dB Below DRW
    • T3/T4 ranging timeouts
    • No Unicast Maintenance opportunities received
    • DHCP WARNING – Non-critical field invalid in response

I’ve also monitored performance using ThinkBroadband BQM and observed clear packet loss and latency spikes aligning with the modem errors.

 

Request:

Please can this be reviewed and, if appropriate, escalated to your network or provisioning team? I am happy to accept a technician visit if the purpose is to check the external line or cabinet, but I want to avoid unnecessary in-home diagnostics, which have already been completed.

39 Replies

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  • Nednats's avatar
    Nednats
    Dialled in
    18 days ago

    The technician who visited said a re-pull between my property and the cabinet was booked for 20 August. I’ve had no written confirmation of this, and @Daniel_Et has advised that nothing is currently showing on my account. With that date now only two days away, I’m concerned the work hasn’t actually been scheduled. I’m waiting on confirmation or a realistic new date.

  • Matthew_ML's avatar
    Matthew_ML
    Icon for Forum Team rankForum Team
    16 days ago

    Hey Nednats, thank you for reaching out and we are so sorry to hear about this appointment not showing.

    We can see you are currently in DM with my colleague, please go back to this DM if you need any further information.

  • Nednats's avatar
    Nednats
    Dialled in
    15 days ago

    Quick update following today’s engineer visit:

    • The engineer confirmed again that the issue is with the drop cable between my property and the cabinet.
    • They said there’s a construction issue — apparently a blockage under the road — so the cable can’t just be pulled through.
    • A permit will need to be applied for before the work can be carried out.
    • They told me the re-pull is expected to be completed before 10 September, but admitted they weren’t sure why I hadn’t already been told this.

    So at this point I’m waiting on confirmation of when the permit will be approved and the work scheduled.

  • Nednats's avatar
    Nednats
    Dialled in
    2 days ago

    Just an update on my situation. Yesterday (2nd September) a subcontractor attended unexpectedly and carried out a repull. This came as a surprise as I had previously been told there was a construction issue requiring permits.

    Unfortunately, the repull hasn’t resolved the fault. My monitoring shows upstream power levels are now in the mid-50s dBmV (previously around 46–47 dBmV). The ThinkBroadband BQM continues to show high latency spikes and packet loss, and the Hub logs are still reporting errors.

     

    Daniel_Et had previously shared feedback from the Area Field Manager suggesting the drop cable might not be the root cause and my results seem to support that. It looks like there is still an upstream fault further into the network.

    Thanks to everyone here who’s followed along — I’ll continue to post updates.

  • fizz's avatar
    fizz
    Fibre optic
    2 days ago

    I feel your pain. I had problems like this for 22 months with two repulls (the first was the wrong size cable the second had the cable ends bodged on and did not work) and it took I think 13 or 14 visits from engineers until I finally got one who could disagnose and fix the problem in the cabinet in the end..