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 dBmVDOCSIS 3.1 channels: detected but not fully lockingRepeated modem log entries including:RNG-RSP CCAP Commanded Power in Excess of 6 dB Below DRWT3/T4 ranging timeoutsNo Unicast Maintenance opportunities receivedDHCP WARNING – Non-critical field invalid in responseI’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.

Line noise is extremely difficult to trace. They often have to take extreme measures by removing everyone on the cabinet and replacing them one by one or what we used to call a ‘binary chop’. That is take out half the users, see if problem still exists, if not swap to the other half and split that in half and on until you find the fault. Often caused by non VM coax as reported many times on the board.

Can you post your downstream and upstream stats and network log.

With upstream power that high I can understand 3.1 not connecting. The cause of this can be 1) you are a long way from street cabinet, moving to another tap on the cabinet may fix, 2) bad coax, 3) on wrong tap, 4) failing amplifier in street cabinet. All these require a technicians visit.

It is not "falling back" to 3.0, because your primary channel is not 3.1. The one has nothing to do with the other.

What I'm trying to say is that you are misunderstanding this information. You have 3.1 channels in your bonding group. Therefore you are using 3.1. Forget about what the primary channel is.

Forum Discussion

Nednats

Up to speed

5 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.

74 Replies

Nednats
Up to speed
24 days ago
The last 24 hours:
Nednats
Up to speed
23 days ago
I wanted to share some monitoring data following a series of upstream issues on 2 November 2025, between 18:45 and 18:50. During this time, my connection dropped repeatedly, and my Hub 5 logs recorded multiple T2/T3 timeouts, “No Maintenance Broadcasts for Ranging” messages, and a TCS Partial Service event.
The connection re-established itself after a few minutes, but the ThinkBroadband BQM shows clear packet loss and latency spikes during that same window. My logs also recorded a sharp dip in upstream power across all channels, which then gradually recovered.
Example log entries:
18:45:56 – 16 consecutive T3 timeouts on upstream channels 0–4
18:46:31 – No Maintenance Broadcasts (T2 timeout)
18:49:58 – TCS Partial Service
18:50:11 – CM-STATUS Event Type 5 (channels 18–36)

Everything points to a short-lived upstream noise or node-level issue, rather than anything inside my property. The line has been stable since, but these recurring bursts match what I’ve been observing for several months.
How do I get this investigated by the Network team?
- Vikki_M
  Forum Team
  21 days ago
  Hi Nednats,
  
  Thanks for your post and welcome back to our community.
  
  We're sorry to hear you're still having some service issues.
  
  Do you have a complaint raised currently for these concerns?
  
  Please pop back to us when you can.
  - Nednats
    Up to speed
    20 days ago
    C-2008256836

Forum Discussion

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

74 Replies

Related Content

upstream

Atom restart failure

Upstream power too high?

Recording Failure

TV 360 Upgrade failure