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Yorkshirelion's avatar
Yorkshirelion
On our wavelength
21 days ago
Solved

Packet loss issue?

Hi, I seem to be having packet loss issues at the moment, very evident when playing online games, or running any test I will see the packet loss noted at around 3%.

I ran my Hub stats into AI and got the following;

  1. Downstream Power Levels
  • Range: from +3.7 dBmV (channel 11) down to +0.7 dBmV (channels 28-30)
  • Ideal range for Virgin: -6 to +10 dBmV, recommended ±7 dBmV, best within ±5 dBmV

Your levels are technically within spec, but the spread is about 3 dB across the band and they tilt downwards with frequency (lower frequencies stronger, higher frequencies weaker).
The lowest channels are sitting at +0.7 to +0.9 dBmV – this is very close to the bottom edge of acceptable. Virgin’s own engineers often say anything under +1 dBmV starts to become marginal, especially if it drops further in hot weather or with temperature changes.2. Downstream SNR / RxMER

  • 3.0 channels: 36–38 dB → perfectly fine for QAM256 (needs >33-34 dB minimum)
  • 3.1 channel (OFDMA): the RxMER column shows “0” which is normal – it’s not reported the same way. The important figure is the PLC Power at +2.5 dBmV – healthy.

No noise issues visible here.3. Error counters – this is the key part3.0 channels (QAM256):

  • Almost completely clean – only a handful of Pre-RS errors on the very lowest frequency channels and zero Post-RS (uncorrectable) errors on any 3.0 channel.
  • This is excellent – basically no packet loss coming from the 3.0 part of the spectrum.

3.1 channel (channel 159 – the high-split OFDMA channel that carries most of your speed):

  • Corrected errors: 582,918,780
  • Uncorrectable errors: 0

That corrected number is huge – over half a billion FEC-corrected codewords.
But crucially zero uncorrectables.What this means: The 3.1 channel is having to work quite hard correcting errors (likely because some of your downstream power levels are on the low side and possibly some ingress/noise on the higher frequencies), but the modem is successfully correcting everything before it turns into actual packet loss.So right now you are not seeing packet loss that reaches your devices – the hub is fixing it all at the physical layer.

So it would seem that I am not getting any packet loss, however when you look at the thinkbroadband BQM you can see the packet loss.

What can I do about this?

Also my upload speed is currently around 22Mbps on the Gig1 plan.

packet loss
  • Yorkshirelion's avatar
    Yorkshirelion
    12 days ago

    This issue is now fixed, I tried to put a picture of the line stats and explanation as to what happened but it keeps just disappearing, or more accurately not getting past moderation for some unknown reason. Either way after the engineer visit the issue is now resolved.

23 Replies

  • Adduxi's avatar
    Adduxi
    Very Insightful Person
    21 days ago

    What Hub are you using?  Post the power levels and network log for comment please.  Check your connections from the Hub to the outside,  they should be "finger" tight and no sign of corrosion.

    Run the full speed tests here  http://www.samknows.com/realspeed and post the results.  Preferably with a wired connection.

    • Yorkshirelion's avatar
      Yorkshirelion
      On our wavelength
      21 days ago

      I think I have possibly fixed the issue now, please tell me if I'm wrong.

      I went and had a look outside at the brown box, it is sealed but the equipment wasn't screwed in all the way etc and the box whilst sealed wouldn't take much to open.

      I disconnected the fibre connected, not the coax convertor just the fibre part and now it appears that I have fixed that issue but my upload is still capped at a very low speed possibly due to all the line errors I was having. Here are the stats now since I have reseated the fibre cable.

      Downstream Channel | Frequency (Hz) | Power (dBmV) | SNR (dB) | Modulation | Channel ID ---|---|---|---|---|--- 1 | 379000000 | 1.1 | 38 | QAM 256 | 31 2 | 139000000 | 2.8 | 37 | QAM 256 | 1 3 | 147000000 | 2.7 | 37 | QAM 256 | 2 4 | 155000000 | 2.8 | 38 | QAM 256 | 3 5 | 163000000 | 2.9 | 38 | QAM 256 | 4 6 | 171000000 | 2.9 | 38 | QAM 256 | 5 7 | 179000000 | 3.1 | 38 | QAM 256 | 6 8 | 187000000 | 3.3 | 38 | QAM 256 | 7 9 | 195000000 | 3.7 | 38 | QAM 256 | 8 10 | 203000000 | 3.8 | 38 | QAM 256 | 9 11 | 211000000 | 3.9 | 38 | QAM 256 | 10 12 | 219000000 | 3.7 | 38 | QAM 256 | 11 13 | 227000000 | 3.4 | 38 | QAM 256 | 12 14 | 235000000 | 3.2 | 38 | QAM 256 | 13 15 | 243000000 | 2.9 | 38 | QAM 256 | 14 16 | 251000000 | 2.5 | 38 | QAM 256 | 15 17 | 259000000 | 2.1 | 38 | QAM 256 | 16 18 | 267000000 | 1.8 | 38 | QAM 256 | 17 19 | 275000000 | 1.5 | 38 | QAM 256 | 18 20 | 283000000 | 1.4 | 38 | QAM 256 | 19 21 | 291000000 | 1.3 | 38 | QAM 256 | 20 22 | 299000000 | 1.2 | 38 | QAM 256 | 21 23 | 307000000 | 1.3 | 38 | QAM 256 | 22 24 | 315000000 | 1.5 | 38 | QAM 256 | 23 25 | 323000000 | 1.5 | 38 | QAM 256 | 24 26 | 331000000 | 1.3 | 38 | QAM 256 | 25 27 | 339ッチ000000 | 1.1 | 38 | QAM 256 | 26 28 | 347000000 | 1.1 | 38 | QAM 256 | 27 29 | 355000000 | 0.9 | 38 | QAM 256 | 28 30 | 363000000 | 0.9 | 37 | QAM 256 | 29 31 | 371000000 | 1.0 | 38 | QAM 256 | 30 32 | 387000000 | 1.0 | 38 | QAM 256 | 32 Downstream (Post RS Errors) Channel | Locked Status | RxMER (dB) | Pre RS Errors | Post RS Errors ---|---|---|---|--- 1 | Locked | 38 | 0 | 0 2 | Locked | 37 | 0 | 0 ... (and the rest exactly the same – all zeros in your case) 3.1 Downstream Channel Channel ID | Locked Status | PLC Power (dBmV) | Corrected | Uncorrectable ---|---|---|---|--- 159 | Locked | 2.8 | 14539533 | 0

      • Adduxi's avatar
        Adduxi
        Very Insightful Person
        21 days ago

        If you suspect the fibre to be in anyway compromised you should insist on a tech visit.  Fibre needs careful handling as any speck of dirt will affect the light levels.  As for the 3.1 correctable, that’s over 14 million is a short time. Mine, by comparison, is about 1.2 million over 2 months of uptime.  Something is amiss.

  • Yorkshirelion's avatar
    Yorkshirelion
    On our wavelength
    21 days ago

    Since I replugged in the fibre plug to the adapter outside the packet loss has stopped on the broadband line monitor and the upload speed has returned to 100mbps. Should I contact Virgin Media and ask them to tighten up the box and components inside to prevent this from happening again?

  • Yorkshirelion's avatar
    Yorkshirelion
    On our wavelength
    18 days ago

    I have seen some packet loss again today, do these stats look ok or should I try and arrange a engineer to have a look?

    **Downstream bonded channels** Channel | Frequency (Hz) | Power (dBmV) | SNR (dB) | Modulation | Channel ID --|--|--|--|--|-- 1 | 379000000 | 1.1 | 38 | QAM 256 | 31 2 | 139000000 | 2.8 | 37 | QAM 256 | 1 3 | 147000000 | 2.7 | 37 | QAM 256 | 2 4 | 155000000 | 2.8 | 37 | QAM 256 | 3 5 | 163000000 | 2.9 | 38 | QAM 256 | 4 6 | 171000000 | 3.0 | 38 | QAM 256 | 5 7 | 179000000 | 3.1 | 38 | QAM 256 | 6 8 | 187000000 | 3.3 | 37 | QAM 256 | 7 9 | 195000000 | 3.8 | 38 | QAM 256 | 8 10 | 203000000 | 3.8 | 38 | QAM 256 | 9 11 | 211000000 | 3.9 | 38 | QAM 256 | 10 12 | 219000000 | 3.7 | 38 | QAM 256 | 11 13 | 227000000 | 3.5 | 38 | QAM 256 | 12 14 | 235000000 | 3.2 | 38 | QAM 256 | 13 15 | 243000000 | 3.0 | 38 | QAM 256 | 14 16 | 251000000 | 2.6 | 38 | QAM 256 | 15 17 | 259000000 | 2.2 | 38 | QAM 256 | 16 18 | 267000000 | 1.8 | 38 | QAM 256 | 17 19 | 275000000 | 1.6 | 38 | QAM 256 | 18 20 | 283000000 | 1.4 | 38 | QAM 256 | 19 21 | 291000000 | 1.4 | 38 | QAM 256 | 20 22 | 299000000 | 1.3 | 38 | QAM 256 | 21 23 | 307000000 | 1.4 | 38 | QAM 256 | 22 24 | 315000000 | 1.5 | 38 | QAM 256 | 23 25 | 323000000 | 1.5 | 38 | QAM 256 | 24 26 | 331000000 | 1.4 | 38 | QAM 256 | 25 27 | 339000000 | 1.1 | 38 | QAM 256 | 26 28 | 347000000 | 1.1 | 38 | QAM 256 | 27 29 | 355000000 | 1.0 | 38 | QAM 256 | 28 30 | 363000000 | 1.0 | 38 | QAM 256 | 29 31 | 371000000 | 1.1 | 38 | QAM 256 | 30 32 | 387000000 | 1.0 | 38 | QAM 256 | 32 **Downstream errors (Post RS = uncorrectable)** Channel | Locked Status | RxMER (dB) | Pre RS Errors | Post RS Errors --|--|--|--|-- 1 | Locked | 38 | 0 | 0 2 | Locked | 37 | 266 | 0 3 | Locked | 37 | 171 | 0 4 | Locked | 37 | 79 | 0 5 | Locked | 38 | 51 | 0 6 | Locked | 38 | 26 | 0 7 | Locked | 38 | 10 | 0 8 | Locked | 37 | 4 | 0 9 | Locked | 38 | 5 | 0 10 | Locked | 38 | 0 | 0 11 | Locked | 38 | 6 | 0 12 | Locked | 38 | 3 | 0 13 | Locked | 38 | 11 | 0 14 | Locked | 38 | 4 | 0 15 | Locked | 38 | 1 | 0 16 | Locked | 38 | 6 | 0 17 | Locked | 38 | 0 | 0 18 | Locked | 38 | 4 | 0 19 | Locked | 38 | 3 | 0 20 | Locked | 38 | 4 | 0 21 | Locked | 38 | 4 | 0 22 | Locked | 38 | 4 | 0 23 | Locked | 38 | 3 | 0 24 | Locked | 38 | 3 | 0 25 | Locked | 38 | 4 | 0 26 | Locked | 38 | 2 | 0 27 | Locked | 38 | 1 | 0 28 | Locked | 38 | 4 | 0 29 | Locked | 38 | 2 | 0 30 | Locked | 38 | 1 | 0 31 | Locked | 38 | 2 | 0 32 | Locked | 38 | 4 | 0 **3.1 Downstream channel (OFDM)** Channel ID | Lock Status | RxMER (dB) | Power (dBmV) | Corrected | Uncorrectable --|--|--|--|--|-- 159 | Locked | N/A | 2.7 | 2289397651 | 7
    • gitty's avatar
      gitty
      On our wavelength
      18 days ago

      Nothing there can explain your packet loss. Can you post the upstream channels and network log?

  • Yorkshirelion's avatar
    Yorkshirelion
    On our wavelength
    18 days ago

    I noticed that last night there was a power cut and when the virgin has come back on I have a different gateway IP address. Can the ip address affect the way the data travels, I know this sounds strange but my stats which I can't post right now as I'm out are perfectly normal, the only thing that has changed is the external ip address?

     

  • legacy1's avatar
    legacy1
    Alessandro Volta
    18 days ago

    So does BQM look better now?

    If you done a tracert before and after your IP changed that would of shown if the routing has changed but I wouldn't think it would?

    Besides if the problem is at the docsis link then nothing to do with routing  

    • Yorkshirelion's avatar
      Yorkshirelion
      On our wavelength
      18 days ago

      I factory reset the hub and it gave me a new ip address, then I set it to modem only mode and it is back using the ip address I had before the factory reset. I also see that I am still getting packet loss on the BQM.

      Channel  Frequency(Hz)  Power(dBmV)  SNR(dB)  Modulation  ChannelID
      1        379000000      1            38       QAM256      31
      2        139000000      2.6          37       QAM256      1
      3        147000000      2.6          37       QAM256      2
      4        155000000      2.8          37       QAM256      3
      5        163000000      2.8          38       QAM256      4
      6        171000000      2.8          38       QAM256      5
      7        179000000      3            38       QAM256      6
      8        187000000      3.2          38       QAM256      7
      9        195000000      3.6          38       QAM256      8
      10       203000000      3.7          38       QAM256      9
      11       211000000      3.8          38       QAM256      10
      12       219000000      3.6          38       QAM256      11
      13       227000000      3.4          38       QAM256      12
      14       235000000      3.1          38       QAM256      13
      15       243000000      2.8          38       QAM256      14
      16       251000000      2.5          38       QAM256      15
      17       259000000      2.1          38       QAM256      16
      18       267000000      1.7          38       QAM256      17
      19       275000000      1.5          38       QAM256      18
      20       283000000      1.3          38       QAM256      19
      21       291000000      1.2          38       QAM256      20
      22       299000000      1.2          38       QAM256      21
      23       307000000      1.3          38       QAM256      22
      24       315000000      1.4          38       QAM256      23
      25       323000000      1.4          38       QAM256      24
      26       331000000      1.3          38       QAM256      25
      27       339000000      1            38       QAM256      26
      28       347000000      1            38       QAM256      27
      29       355000000      0.9          38       QAM256      28
      30       363000000      0.9          38       QAM256      29
      31       371000000      0.9          38       QAM256      30
      32       387000000      0.9          38       QAM256      32

      Channel  Status  RxMER(dB)  PreRS  PostRS
      1        Locked  38         0      0
      2        Locked  37         0      0
      3        Locked  37         0      0
      4        Locked  37         0      0
      5        Locked  38         0      0
      6        Locked  38         0      0
      7        Locked  38         0      0
      8        Locked  38         0      0
      9        Locked  38         0      0
      10       Locked  38         0      0
      11       Locked  38         0      0
      12       Locked  38         0      0
      13       Locked  38         0      0
      14       Locked  38         0      0
      15       Locked  38         0      0
      16       Locked  38         0      0
      17       Locked  38         0      0
      18       Locked  38         0      0
      19       Locked  38         0      0
      20       Locked  38         0      0
      21       Locked  38         0      0
      22       Locked  38         0      0
      23       Locked  38         0      0
      24       Locked  38         0      0
      25       Locked  38         0      0
      26       Locked  38         0      0
      27       Locked  38         0      0
      28       Locked  38         0      0
      29       Locked  38         0      0
      30       Locked  38         0      0
      31       Locked  38         0      0
      32       Locked  38         0      0

      Channel  Width(MHz)  FFT  ActiveSubs  Modulation    FirstSubcarrier(Hz)
      159      94          4K   1840        QAM4096       1108

      ChannelID  Status  RxMER(dB)  PLC Power(dBmV)  Corrected  Uncorrectable
      159        Locked  0          2.7              17003983   0

      Channel  Frequency(Hz)  Power(dBmV)  SymbolRate(ksps)  Modulation  ChannelID
      0        60300000       30.8         5120              QAM64       9
      1        53700000       31           5120              QAM64       10
      2        46200000       31           5120              QAM64       11
      3        39400000       30.8         5120              QAM64       12
      4        32600000       31.3         5120              QAM64       13
      5        23600000       31.3         5120              QAM64       14

      Channel  Type    T1  T2  T3  T4
      0        ATDMA   0   0   0   0
      1        ATDMA   0   0   0   0
      2        ATDMA   0   0   6   0
      3        ATDMA   0   0   0   0
      4        ATDMA   0   0   0   0
      5        ATDMA   0   0   0   0

      I am also seeing this when I look at the virgin media status, it was saying this the other day as well but went back to normal;

      Intermittent signal in your area

      To make sure it’s not the kit in your home that’s causing the issue, follow our steps to check your kit.

  • legacy1's avatar
    legacy1
    Alessandro Volta
    18 days ago

    If you can test with a PC to the hub in modem mode you can copy your router MAC (not hub) to your PC NIC so you don't have to reboot the hub and run cmd

    ping -n 200 194.168.4.100

    run that about three times and see what you get then run it with you router setup.  

    • Yorkshirelion's avatar
      Yorkshirelion
      On our wavelength
      17 days ago

      I will give this a go when I am back at home later and report back.

      Quick side note, there is still some packet loss on my thinkbroadband graph, should there ever be any packet loss on there or does that indicate there is an issue somewhere? I am not talking about if the router reboots and then you can see it for obvious reasons.

      • legacy1's avatar
        legacy1
        Alessandro Volta
        17 days ago

        It can be the case that you see no packet loss but some times you see a blip red dot every like 3 hours for a single packet loss the timing can be random but if your getting continues loss thats a problem. 

  • Yorkshirelion's avatar
    Yorkshirelion
    On our wavelength
    14 days ago

    Ok, so I am still getting lots of jitter and ping bursts when gaming, although I don't have the constant packet loss like at the start of the thread my ping is all over the place.

    This morning I took ar reading of my corrected errors on the 3.1 downstream.

    9:00 am → 116,982,865

     9:05 am → 118,957,656

    Difference: 1,974,791 corrected errors in exactly 5 minutes.

    That is ~6,583 corrected errors every second (almost 400,000 per minute)

    So just under 2 million in 5 minutes, I am assuming at this point I need someone to look at the line? Can someone from the forum team sort this or do I have to try and explain it over the phone?

  • Yorkshirelion's avatar
    Yorkshirelion
    On our wavelength
    13 days ago

    I have arranged an engineer visit tomorrow but I am wondering if I should cancel it as I don't want to be charged if no fault is found.

    I am finding conflicting information on whether or not having 698599318 corrected errors in around 21 hours but 0 uncorrected is a problem on the 3.1 downstream.

    The packet loss seems to have stopped.

    • Anonymous's avatar
      Anonymous
      13 days ago

      "I am finding conflicting information on whether or not having 698599318 corrected errors in around 21 hours but 0 uncorrected is a problem on the 3.1 downstream."

      No actually that’s fine. The reason you are finding conflicting information is that some posters don’t get that the way that DOCSIS 3.1 does its error correction is completely different to the way that 3.0 did.

      Not helped by the poor wording of the hub’s reporting ‘xyz corrected errors’ sounds bad, but doesn’t actually mean what you might think.

      • Yorkshirelion's avatar
        Yorkshirelion
        On our wavelength
        13 days ago

        So I should cancel the appointment as my line is functioning properly?

  • Yorkshirelion's avatar
    Yorkshirelion
    On our wavelength
    12 days ago

    Line is fixed and performing much better, new router, new power adapter for the brown box and the fibre was cleaned. Packet loss and latency spikes are now gone.

  • Yorkshirelion's avatar
    Yorkshirelion
    On our wavelength
    12 days ago

    This issue is now fixed, I tried to put a picture of the line stats and explanation as to what happened but it keeps just disappearing, or more accurately not getting past moderation for some unknown reason. Either way after the engineer visit the issue is now resolved.