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Zoomeh's avatar
Zoomeh
Tuning in
10 months ago

Intermittent issue causing slow download speeds

Hey VM community.
There's a long running issue in my area that is progressively getting worse with it now occurring multiple times a day for extended periods. It looks to be a noise issue with SNR on some channels occasionally dropping to 0.
Weirdly enough it only affects download speeds and latency.
I'm IT inclined and have tried the usual troubleshooting but this looks to be something a VM engineer will have to resolve.

Gig1.
Hub5.
Modem Mode.

Here's a speedtest showing the issue.

My BQM for today.

Modem Stats:
Modem was restarted 30 mins before these readings.

Cable Modem StatusItem Status TypeChannel Overview Downstream Upstream

Cable Modem StatusOnlineDOCSIS 3.0
Primary downstream channelLockedSC-QAM
DOCSIS 3.0 channels305
DOCSIS 3.1 channels11

3.0 Downstream channels

Channel Frequency (Hz) Power (dBmV) SNR (dB) Modulation Channel ID
1611000000-7.834QAM 25632
2387000000-8.327QAM 2564
3419000000-831QAM 2568
4427000000-7.828QAM 2569
5451000000-8.334QAM 25612
6459000000-8.533QAM 25613
7483000000-8.633QAM 25616
8491000000-8.732QAM 25617
9515000000-8.732QAM 25620
10523000000-8.432QAM 25621
11547000000-7.631QAM 25624
12555000000-7.232QAM 25625
13579000000-7.133QAM 25628
14587000000-7.234QAM 25629
15603000000-7.735QAM 25631
16619000000-7.833QAM 25633
17627000000-7.935QAM 25634
18635000000-8.335QAM 25635
19643000000-8.434QAM 25636
20651000000-8.534QAM 25637
21659000000-8.434QAM 25638
22667000000-8.534QAM 25639
23675000000-8.534QAM 25640
24683000000-8.135QAM 25641
25691000000-8.734QAM 25642
26699000000-8.934QAM 25643
27707000000-8.835QAM 25644
28715000000-8.934QAM 25645
29723000000-9.235QAM 25646
30731000000-9.634QAM 25647

3.0 Downstream channels

Channel Locked Status RxMER (dB) Pre RS Errors Post RS Errors
1Locked34349500
2Locked27619324646231823
3Locked3138996180
4Locked2866176698676589
5Locked34500134364
6Locked3314276929508
7Locked331009620
8Locked325417640
9Locked324344290
10Locked3229300164
11Locked31391841151
12Locked3231675816
13Locked33895250
14Locked3499920
15Locked3552350
16Locked33794900
17Locked3521400
18Locked3518280
19Locked3436100
20Locked3432350
21Locked3444990
22Locked34187890
23Locked34113540
24Locked3526220
25Locked3472660
26Locked3472860
27Locked3542180
28Locked348111433
29Locked3544411887
30Locked3451410

3.1 Downstream channels

Channel Channel Width (MHz) FFT Type Number of Active Subcarriers Modulation (Active Profile) First Active Subcarrier (Hz)
1591904K3736QAM 4096148

3.1 Downstream channels

Channel ID Locked Status RxMER Data (dB) PLC Power (dBmV) Corrected errors (Active Profile) Uncorrectable errors (Active Profile)
159Locked34-11.16146532227634850

 

3.0 Upstream channels

Channel Frequency (Hz) Power (dBmV) Symbol Rate (ksps) Modulation Channel ID
04960000055.35120QAM 641
14310000054.85120QAM 642
23660000054.55120QAM 643
33010000054.35120QAM 644
42360000053.35120QAM 645

3.0 Upstream channels

Channel Channel Type T1 Timeouts T2 Timeouts T3 Timeouts T4 Timeouts
0ATDMA0000
1ATDMA0000
2ATDMA0040
3ATDMA0000
4ATDMA0000

3.1 Upstream channels

Channel Channel Width (MHz) Power (dBmV) FFT Type Modulation
61049.02KQAM 256

3.1 Upstream channels

Channel Channel Type Number of Active Subcarriers First Active Subcarrier (Hz) T3 Timeouts T4 Timeouts
6OFDMA2007400000000

 

5 Replies

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  • Zoomeh's avatar
    Zoomeh
    Tuning in
    10 months ago

    Network Log

    Time Priority Description
    01-08-2024 15:51:02noticeCM-STATUS message sent. Event Type Code: 4; Chan ID: 4; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
    01-08-2024 15:50:52warningMDD message timeout;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
    01-08-2024 15:41:41noticeCM-STATUS message sent. Event Type Code: 4; Chan ID: 4; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
    01-08-2024 15:41:22warningMDD message timeout;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
    01-08-2024 15:34:53noticeCM-STATUS message sent. Event Type Code: 4; Chan ID: 4; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
    01-08-2024 15:34:42warningMDD message timeout;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
    01-08-2024 15:28:42noticeCM-STATUS message sent. Event Type Code: 16; Chan ID: 159; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 3.;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
    01-08-2024 15:28:23noticeUS profile assignment change. US Chan ID: 6; Previous Profile: 13; New Profile: 11 13.;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
    01-08-2024 15:28:23warningDBC-REQ Mismatch Between Calculated Value for P1.6hi Compared to CCAP Provided Value;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
    01-08-2024 15:28:19noticeREGISTRATION COMPLETE - Waiting for Operational status
    01-08-2024 15:28:14warningRNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
    01-08-2024 15:28:14warningDynamic Range Window violation
    01-08-2024 15:28:14warningREG-RSP-MP Mismatch Between Calculated Value for P1.6hi Compared to CCAP Provided Value;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
    01-08-2024 15:28:14warningRNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
    01-08-2024 15:28:14warningRCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
    01-08-2024 15:28:14warningRNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
    01-08-2024 15:28:14warningDynamic Range Window violation
    01-08-2024 15:28:14warningDynamic Range Window violation
    01-08-2024 15:28:14warningDynamic Range Window violation
    01-08-2024 15:28:14warningRNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
    01-08-2024 15:28:08noticeDS profile assignment change. DS Chan ID: 32; Previous Profile: ; New Profile: 1 2 3.;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
    01-08-2024 15:28:04noticeTLV-11 - unrecognized OID;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
    01-08-2024 15:28:02warningDHCP WARNING - Non-critical field invalid in response ;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
    01-08-2024 15:28:00noticeHonoring MDD; IP provisioning mode = IPv4
    01-08-2024 15:27:26criticalNo Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
    01-08-2024 15:27:20criticalSYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
    01-08-2024 15:27:19criticalCable Modem Reboot because of - HW or Power-On Reset
    23-07-2024 09:51:54criticalNo Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
    23-07-2024 09:51:48criticalSYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
    23-07-2024 09:51:47criticalCable Modem Reboot because of - HW or Power-On Reset
    22-07-2024 14:47:09criticalNo Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
    22-07-2024 14:47:01criticalSYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
     

     

    • Beth_G's avatar
      Beth_G
      Icon for Forum Team rankForum Team
      10 months ago

      Hi Zoomeh

      Thanks for your post, welcome to the Community Forums.

      Sorry to see you're having trouble with your connection and speeds. You're quite right, your downstream channels are too low and so we'll need to get an engineer out to take a look. There's no known outages in your area that could be causing this by the looks of it.

      I've dropped you a PM 😊

  • Client62's avatar
    Client62
    Alessandro Volta
    10 months ago

    The Downstream power levels should be between -7 to +7 with a max of +10 dBmV
    most channels are too low resulting in many errors that can not be corrected.

    3.0 Downstream channels

    Channel Frequency (Hz) Power (dBmV) SNR (dB) Modulation Channel ID
    1611000000-7.834QAM 25632
    2387000000-8.327QAM 2564
    3419000000-831QAM 2568
    4427000000-7.828QAM 2569
    5451000000-8.334QAM 25612
    6459000000-8.533QAM 25613
    7483000000-8.633QAM 25616
    8491000000-8.732QAM 25617
    9515000000-8.732QAM 25620
    10523000000-8.432QAM 25621

     

    3.1 Downstream channels

    Channel ID Locked Status RxMER Data (dB) PLC Power (dBmV) Corrected errors (Active Profile) Uncorrectable errors (Active Profile)
    159Locked34-11.16146532227634850
    • Anonymous's avatar
      Anonymous
      10 months ago

      Have you thought about moving home, it'll be quicker, easier and less stressful than getting a reliable service from this crowd.

  • Zoomeh's avatar
    Zoomeh
    Tuning in
    9 months ago

    Happy to report that I had a competent engineer who replaced everything except the main coax run to my property and sorted out the mess in the cab which has brought the power levels back in to spec and solved the dropouts and speed issues.
    Cheers.