I'm consistently sitting around the max limit of 10 dBmV and phone support don't seem to get the message.My connections constantly poor, the modems always switching doing US profile assignment changes and when this happens, I lose connection.T4 timeouts are common.T3 timeouts are sometimes in the thousands.3.1 Downstream channel corrected errors are now in the BILLIONS and a fair few uncorrected errors. You have replaced everything, cable to house has been done, internal cables have been replaced, repeated splitter swaps, the techs just do something to humor me and close the call knowing full well it doesn't fix the power issues.I assume I've been put onto a higher tap to fix someone else's issue as it seems to be the norm when working in the cabinet.I've had enough, I pay a fortune for a poor service and the supports never been able to nail this. The last tech who came said it's an issue that isn't related to anything after the cabinet to my house, and this was never followed up, just more excuses.

Seems like they have missed something that needs replacing I take it your in modem mode? given you said VM question your internal network? set up a BQM Broadband Quality Monitor | thinkbroadband

Check with Area faults on 0800 561 0061 If you have a VM landline 150 this goes down to post code level. You could also try the web service status page, but this is not recommended as it only covers issues that affect a very large number of customers.VM will not dispatch any technicians while an area fault exists.If no area faults found:The primary place to report faults or for service requests is Customer Services on 0345 454 1111/150 if you have a VM landline or wait two or three days for a VM staff member to get to your post. This board is not a fault reporting system.

To keep the signals close to the 0dBmV level we have a 6dB Wideband Attenuator on the COAX to the VM Hub. 10dB Wideband Attenuators are also available. When adding Wideband Attenuator the Downstream dBmV level will drop,but the Upstream i.e. the dBmV level transmitted by the Hub will rise.

Hi GoNz0 Thanks for posting and welcome back to the community. Apologies for any broadband issues. I'll send you a PM as you need an engineer visit. Best wishes.

Back to the usual case of no resolution, yet again I had a tech sent out with a minimal explanation of the issue, or more to the point zero information regarding this being an ongoing issue where the issue has been proven time and time again to be nothing to do with the cable running from the cabinet to my house, nothing to do with the cabling around my house as it's all been replaced before, nothing to do with the router (that this time was replaced as it was running slow and hot, well what else will it do when it's logging a billion or more corrected errors, the router is on its knees trying to cope)I still get questioned about my internal network despite repeatedly reminding support or the tech on the day that a drop out with a router log at the same time rules out anything my side and then they agree, ignore everything I say and swap a filter or 2 then close the call.To add to the insult, the tech who arrived Saturday put me up a tap and when questioned about him now pushing me well past the 10db limit that triggered the need for support to send a tech stood looking blank until the penny dropped, then shoved an attenuator in to save walking back to the box, closed the call and left.

Back again with unresolved high Power (dBmV) | Virgin Media Community

23 Replies

GoNz0
Dialled in
5 hours ago
Still no further along, still in worse shape than I was before the 1st visit, power levels borderline too high again and now falling back to QAM32 instead of QAM64 on the upstream
Roger_Gooner
Alessandro Volta
25 days ago
Didn't any tech do a line check at the cabinet plus, if needed, another one at the property?
Sephiroth
Alessandro Volta
25 days ago
Anything Gitty says will be useful.
Corrected errors impose no/negligible load in the modem. The FEC is in-line and is a function of the data stream.
The upstream is a different matter. Constant reassignments suggest congestion to me or noise. On the lower frequency channels, suspect noise. With you being close to the cabinet, upstream power won’t be an issue, subject to the types of attenuator you’ve been given.
Has your coax drop point been checked for water? Corrosion can cause micro-rerflections.
Finally, what is your neighbour’s experience?
- GoNz0
  Dialled in
  4 hours ago
  I assume that's why they faff around in the box on my wall, I would hope anyway.
  No immediate neighbours on VM (sensible people)
  I'm now back to power levels right on the bitter edge of too high, endless profile assignment changes and now the modem won't sync at QAM64 any more, instead it's on 32 after each reboot.
  Oh and a few uncorrectable errors thrown in for good measure.
  Top work from VM NOT!
GoNz0
Dialled in
25 days ago
Tech 3 arrived (was tech 2 back again, Mr 6 months wet behind the ears), rang someone else so tech 4 arrived later that morning.
Messed around for a bit, I couldn't check at the time. Same faults are back including the low power one.
Unreal
GoNz0
Dialled in
2 months ago
I do have trust issues with the VM engineers. Every one has a different opinion on what should be right, Saturdays thought it was fine to bump me up a tap and throw the Power (dBmV) up beyond 10, being at 10 triggered the visit, he left after doing that and fitting a 3db attenuator. Problems persisted the same as before with the internet grinding to a halt and the modem logging a US profile assignment change at the same time.
As nothing changed a senior tech was booked, he arrived, not sure, call it a hunch, after he told me he had only been with VM for 6 months that he wasn't a senior tech and didn't really know what to do about the issue, he told me the power levels were too high (really!) and moved me to the bottom tap, then he said he didn't think RG11 was suitable being around 50m from the cabinet and thought RG6 would be better. To me with some networking background would suggest it's better at keeping the noise out, anyway, he was meant to call back after speaking to his supervisor, I've chased this with the forum rep to see what is being done next, the outcome of today, internets taking longer to load pages, if I pull the modem and hotspot things speed up, if I go to router mode and plug in an RJ45 direct, the internet's slow loading pages again.
in 75 minutes the routers logged 54380637 corrected errors on the downstream 3.1 channel, this has been on ongoing issue, and I can only imagine the modem is running flat out correcting 54 million errors in a little over an hour.
A new error after being dropped down to the lowest tap.
RNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW;CM-MAC=x;CMTS-MAC=x;CM-QOS=1.1;CM-VER=3.1;
- unisoft
  Super solver
  30 days ago
  "RNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value" is a modem error indicating the HUB5 is operating outside its expected Dynamic Range Window, suggesting a possible signal issue or problem with the coaxial cable or splitters. This means the modem's transmission power is significantly lower than what the CCAP (Converged Cable Access Platform) expects to provide a reliable service.
  RNG-RSP: This refers to "Ranging Response," a process where the cable modem communicates with the CCAP to establish a stable connection and transmit data.
  CCAP Commanded Power: This is the power level the CCAP has instructed the modem to use for upstream transmission.
  Excess of 6 dB Below the Value Corresponding to the Top of the DRW: This indicates the modem is transmitting with a power level more than 6 dB lower than what's necessary to stay within the designated Dynamic Range Window. The Dynamic Range Window is a specific power level range needed for stable communication.
  I get all the issue you are having, but not as severe and it's not affecting my speed at the moment.
  The most common causes for this is:
  Moisture in Cables: Water ingress into the coaxial cables can degrade the signal quality. This could be mice/rats in ducting chewing cable or other damage or age.
  A cable that is not up to the job because of distance from cabinet. Cable such as RG11 or similar is better for houses from cabinet, but is not the default installation and requires a cable "re-pull".
  Noise on upstream channels that may be intermittent.
  - gitty
    Tuning in
    25 days ago
    6 dB below the top isn't an actual violation. The window is 12 dB. If a channel is 6 dB below the top, it means it is half way through the window. If possible, the system wants to have all channels in the top half, so the modem tells the CMTS, if it happens, so it may adjust the top (if possible).
    If there are no events logged after the technician was done fiddling with it, it was just caused by a sudden change in levels (the window needed a new top).
- gitty
  Tuning in
  2 months ago
  Can you post your levels and event log? For all the curious minds :)
  You are not the first to get lost in the OFDM corrected errors. Forget it. It's not relevant in your troubleshooting. :)
  - GoNz0
    Dialled in
    2 months ago
    3.0 Upstream channels
    Channel Frequency (Hz) Power (dBmV) Symbol Rate (ksps) Modulation Channel ID
    0 49600000 50 5120 QAM 64 1
    1 43100000 50.5 5120 QAM 64 2
    2 36600000 50.8 5120 QAM 64 3
    3 30100000 51 5120 QAM 64 4
    4 23600000 51.5 5120 QAM 64 5
    3.0 Upstream channels
    Channel Channel Type T1 Timeouts T2 Timeouts T3 Timeouts T4 Timeouts
    0 ATDMA 0 0 1 0
    1 ATDMA 0 0 0 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
    6 10.4 45.5 2K QAM 256
    3.1 Upstream channels
    Channel Channel Type Number of Active Subcarriers First Active Subcarrier (Hz) T3 Timeouts T4 Timeouts
    6 OFDMA 208 74000000 0 0
legacy1
Alessandro Volta
2 months ago
Seems like they have missed something that needs replacing
I take it your in modem mode? given you said VM question your internal network? set up a BQM
Broadband Quality Monitor | thinkbroadband
GoNz0
Dialled in
2 months ago
Back to the usual case of no resolution, yet again I had a tech sent out with a minimal explanation of the issue, or more to the point zero information regarding this being an ongoing issue where the issue has been proven time and time again to be nothing to do with the cable running from the cabinet to my house, nothing to do with the cabling around my house as it's all been replaced before, nothing to do with the router (that this time was replaced as it was running slow and hot, well what else will it do when it's logging a billion or more corrected errors, the router is on its knees trying to cope)
I still get questioned about my internal network despite repeatedly reminding support or the tech on the day that a drop out with a router log at the same time rules out anything my side and then they agree, ignore everything I say and swap a filter or 2 then close the call.
To add to the insult, the tech who arrived Saturday put me up a tap and when questioned about him now pushing me well past the 10db limit that triggered the need for support to send a tech stood looking blank until the penny dropped, then shoved an attenuator in to save walking back to the box, closed the call and left.
- Client62
  Alessandro Volta
  2 months ago
  Reboot the VM Hub to clear down the old error counts.
  
  Following the change of tap and the fitting of an attenuator, are the Downstream & Upstream signal levels back to normal and the errors reduced ?
  - GoNz0
    Dialled in
    2 months ago
    It was rebooted, levels in check, nothings changed, continuous US profile assignment changes and billions of uncorrected errors.
    Senior tech booked, I don't expect a resolution. City fibre looking like the only option, at least with unresolved faults I can exit the contract penalty free.
John_GS
Forum Team
2 months ago
Hi GoNz0

Thanks for posting and welcome back to the community. Apologies for any broadband issues.

I'll send you a PM as you need an engineer visit.

Best wishes.
Client62
Alessandro Volta
2 months ago
To keep the signals close to the 0dBmV level we have a 6dB Wideband Attenuator on the COAX to the VM Hub. 10dB Wideband Attenuators are also available.

When adding Wideband Attenuator the Downstream dBmV level will drop,
but the Upstream i.e. the dBmV level transmitted by the Hub will rise.
Tudor
Very Insightful Person
2 months ago
Check with Area faults on 0800 561 0061 If you have a VM landline 150 this goes down to post code level. You could also try the web service status page, but this is not recommended as it only covers issues that affect a very large number of customers.
VM will not dispatch any technicians while an area fault exists.
If no area faults found:
The primary place to report faults or for service requests is Customer Services on 0345 454 1111/150 if you have a VM landline or wait two or three days for a VM staff member to get to your post. This board is not a fault reporting system.