Forum Discussion

HergestPhil's avatar
HergestPhil
Dialled in
2 years ago

Do I have a latency issue?

I was on 250Mbps via a SuperHub 3, but yesterday switched to 1Gbps via Superhub 5.

I initially had a bit of a flakey connection, but reconnected the copper cable to the white wall socket that hadn't been tightened by the engineer properly.  Rebooted router.  BMQ now looks mostly okay, Router stats not too bad.

But various speed/latency/bufferbloat tests give quite a wide range of results.  I was expecting better quality than with the Hub 3, but it felt like I had a more consistent quality connection with my hub 3 250Mbps connection, lower average ping for example playing some games, such as Rocket League.

My Upstream seems rock solid, with all tests showing consistent 100Mbps with low active load latency (grade A on the buffer bloat test, +2ms latency).

It's the download that seems a bit flakey still (buffer bloat test often reports a grade E downstream, with my downstream active load latency at +54ms).

Download speed tests seem to report varying figures, averaging around 780Mbps, running on a PC connected with gigabit ethernet.

Downstream power levels for channels range between 3.8 to 7.5, SNR 41-42.  Over a 24 hour period, I seem to have accululated in the range of 4 to 13 Pre RS errors on each channel.  No Post RS errors though.

3.1 Downstream channels, Active Profile corrected errors is now over 875M (no uncorrectable errors though).

  • I have noticed a small amount of packet loss on BMQ graph.

    2am - 9am had a more consistent latency.  I see more variance in the average latency and maximum latency this afternoon/evening.

  • This seems to suggest that perhaps the connection from the hub to desktop PC (via ethernet cable) is introducing additional latency and jitter.  Are all ports equal on the Hub 5?  Perhaps the ethernet cable should be replaced (it's not marked what grade it is - blue colour, I think it came with the Hub 3).  Would Cat 5E be fine, or should I get Cat 6 or higher?

  • legacy1's avatar
    legacy1
    Alessandro Volta

    Your connection looks fine Buffer Bloat happens on load as to how limiting handles traffic which you may be buffer at the hub normally on lower speed package or at VM gateway to buffer as HFQ should their be load by others in your area meaning you can't hit your full speed.

  • I am less worried about full speed, more worried about latency.  It seems that when I run Rocket League now, I am seeing slightly higher pings (maybe 5-10ms higher than I used to see).  On the BMQ graph during prime times, I am seeing more blue colour than previously, meaning my average ping has more variance (jitter?).  I do wonder if the connection from router to PC is actually adding a bit more latency, and will try to get a new CAT 5E or 6 cable, if that could be the problem?

  • carl_pearce's avatar
    carl_pearce
    Community elder

    All looks normal for a VM connection using DOCSIS.

    In fact it looks like a very good connection in your area.

    My area for comparison (Rebooted at 8pm!):

    Technically there could be a fault in the area, however unsure if VM would acknowledge.

    Assuming your HUB 5 is on the latest firmware what do the upstream stats look like?

    • HergestPhil's avatar
      HergestPhil
      Dialled in

      Here are my downstream stats:

      3.0 Downstream channels

      Channel Frequency (Hz) Power (dBmV) SNR (dB) Modulation Channel ID
      13310000005.340QAM 25625
      21790000007.542QAM 2566
      31870000007.642QAM 2567
      41950000007.742QAM 2568
      52030000007.542QAM 2569
      62110000007.442QAM 25610
      72190000007.342QAM 25611
      82270000007.242QAM 25612
      92350000007.142QAM 25613
      10243000000742QAM 25614
      112510000006.742QAM 25615
      122590000006.441QAM 25616
      132670000006.341QAM 25617
      142750000006.141QAM 25618
      152830000005.941QAM 25619
      162910000005.841QAM 25620
      172990000005.741QAM 25621
      183070000005.841QAM 25622
      193150000005.741QAM 25623
      203230000005.640QAM 25624
      213390000005.341QAM 25626
      223470000005.141QAM 25627
      233550000005.141QAM 25628
      243630000004.941QAM 25629
      253710000004.841QAM 25630
      26379000000541QAM 25631
      273870000004.841QAM 25632
      283950000004.641QAM 25634
      294030000004.541QAM 25635
      304110000004.341QAM 25636
      314190000004.241QAM 25637

      3.0 Downstream channels

      Channel Locked Status RxMER (dB) Pre RS Errors Post RS Errors
      1Locked40260
      2Locked42240
      3Locked42160
      4Locked42260
      5Locked42180
      6Locked42210
      7Locked42170
      8Locked42130
      9Locked42170
      10Locked42130
      11Locked42290
      12Locked41200
      13Locked41120
      14Locked41290
      15Locked41200
      16Locked41260
      17Locked41260
      18Locked41300
      19Locked41320
      20Locked40250
      21Locked41390
      22Locked41350
      23Locked41440
      24Locked41440
      25Locked41470
      26Locked41560
      27Locked41380
      28Locked41490
      29Locked41420
      30Locked41270
      31Locked41420

      3.1 Downstream channels

      Channel Channel Width (MHz) FFT Type Number of Active Subcarriers Modulation (Active Profile) First Active Subcarrier (Hz)
      33944K1840QAM 40961108

      3.1 Downstream channels

      Channel ID Locked Status RxMER Data (dB) PLC Power (dBmV) Corrected errors (Active Profile) Uncorrectable errors (Active Profile)
      33Locked413.230162349185
  • Here's the upstream stats:

    3.0 Upstream channels

    Channel Frequency (Hz) Power (dBmV) Symbol Rate (ksps) Modulation Channel ID
    04960000041.35120QAM 641
    14310000040.55120QAM 642
    23660000040.35120QAM 643
    33010000039.85120QAM 644
    42360000039.35120QAM 645

    3.0 Upstream channels

    Channel Channel Type T1 Timeouts T2 Timeouts T3 Timeouts T4 Timeouts
    0ATDMA0000
    1ATDMA0000
    2ATDMA0000
    3ATDMA0000
    4ATDMA0000

    3.1 Upstream channels

    Channel Channel Width (MHz) Power (dBmV) FFT Type Modulation
    1210.437.22KQAM 256

    3.1 Upstream channels

    Channel Channel Type Number of Active Subcarriers First Active Subcarrier (Hz) T3 Timeouts T4 Timeouts
    12OFDMA2087400000000
  • I have noticed that I get a lag spike, often associated with packet loss, repeatedly exactly every 8 hours, just before 6am, 2pm, 10pm.  Seems to happen every day at exactly the same time.

    • Beth_G's avatar
      Beth_G
      Forum Team

      Hi HergestPhil

      Thanks for your post, I'm sorry to hear you're having a few issues with your broadband.

      Whilst your BQM graph does look good, I've had a look on this end and some of your downstream channel levels are out of spec.

      I can arrange an engineer visit for you to iron out the downstream issues. I've dropped you over a PM so I can take your details.

      • Beth_G's avatar
        Beth_G
        Forum Team

        Hi HergestPhil 

        hanks for getting back to me with your details via PM.

        I've gone ahead and booked in the next available engineer appointment for you. You can view and manage your appointment slot here.

        There are a few things you need to be aware of for the visit. There may be a £25 charge if:

         

        •    The customer is not present for the technician visit (aka a missed appointment).

        •    The fault is due to customer's own equipment.

        •    The fault is due to damage caused by someone at the customer's premises which we were not aware of.

        •    The fault is due to theft, loss, or removal of equipment.

         

        Otherwise, the appointment would be free of charge.

         

        Let us know how the visit goes and if you need anything else 😊
         

  • legacy1's avatar
    legacy1
    Alessandro Volta

    If it run fine in modem mode you can get a better router