Forum Discussion

Ash_'s avatar
Ash_
On our wavelength
2 years ago

1Gig Slow connection DOCSIS 3.1

Hey all, IT/Software engineer here who has signed up for the 1gig package.

I was originally on the 250 MB package which as rock solid for years. Working from home more and uploading/downloading large virtual machine files required the upgrade. I took the plunge last week but the internet speed is very intermittent. 

Some days I can get 1180mbps down and 105 up and the next day it's 450mbps down and 45mb up. I have tried various connection methods including Wifi 6 enabled Macbook Pro, iPhone 14 and iPad. Additionally, I purchased a 2.5gig ethernet adaptor for my Mac thinking there might be congestion on the 2.4/5ghz range but it makes no real difference.

It's like something is going on at the exchange and it then sorts itself out a few hours later. 

I have had an engineer out who looked at everything and it was all over the place then. He replaced a few things and it was ok for a day and it's back doing the same. 

Is this normal for the 1gig connection as I am rarely seeing 1gb download and have only seen over 100mb upload two times. 

I have factory reset the router and also tried just my laptop connected but that makes no difference when it's being slow. 

Cable Modem StatusItem Status TypeChannel Overview Downstream Upstream

Cable Modem StatusOnlineDOCSIS 3.0
Primary downstream channelLockedSC-QAM
DOCSIS 3.0 channels315
DOCSIS 3.1 channels11

3.0 Downstream channels

Channel Frequency (Hz) Power (dBmV) SNR (dB) Modulation Channel ID
13300000002.941QAM 25625
21380000006.740QAM 2561
31460000006.240QAM 2562
41540000005.840QAM 2563
51620000005.640QAM 2564
61700000005.440QAM 2565
71780000005.341QAM 2566
81860000005.141QAM 2567
91940000004.841QAM 2568
102020000004.541QAM 2569
112100000004.641QAM 25610
122580000003.941QAM 25616
132660000003.841QAM 25617
142740000003.641QAM 25618
152820000003.541QAM 25619
162900000003.741QAM 25620
172980000003.741QAM 25621
183060000003.541QAM 25622
193140000003.241QAM 25623
203220000003.141QAM 25624
213380000003.141QAM 25626
223460000002.841QAM 25627
233540000002.541QAM 25628
243620000002.541QAM 25629
253700000002.541QAM 25630
263780000002.341QAM 25631
273860000001.941QAM 25632
283940000001.641QAM 25633
294020000001.741QAM 25634
304100000001.841QAM 25635
315140000000.740QAM 25636

3.0 Downstream channels

Channel Locked Status RxMER (dB) Pre RS Errors Post RS Errors
1Locked4190
2Locked4000
3Locked4020
4Locked4000
5Locked4000
6Locked4000
7Locked4120
8Locked4110
9Locked4100
10Locked4100
11Locked4100
12Locked4100
13Locked4110
14Locked4120
15Locked4120
16Locked4110
17Locked4130
18Locked4130
19Locked4110
20Locked4170
21Locked4140
22Locked4140
23Locked4140
24Locked4180
25Locked4140
26Locked4190
27Locked4160
28Locked4150
29Locked4130
30Locked4160
31Locked40100

3.1 Downstream channels

Channel Channel Width (MHz) FFT Type Number of Active Subcarriers Modulation (Active Profile) First Active Subcarrier (Hz)
37924K1800QAM 40961128

3.1 Downstream channels

Channel ID Locked Status RxMER Data (dB) PLC Power (dBmV) Corrected errors (Active Profile) Uncorrectable errors (Active Profile)
37Locked410.31024890480

3.0 Upstream channels

Channel Frequency (Hz) Power (dBmV) Symbol Rate (ksps) Modulation Channel ID
04960000042.55120QAM 641
14310000041.85120QAM 642
23660000040.55120QAM 643
33010000039.55120QAM 644
42360000038.55120QAM 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
610.438.52KQAM 256

3.1 Upstream channels

Channel Channel Type Number of Active Subcarriers First Active Subcarrier (Hz) T3 Timeouts T4 Timeouts
6OFDMA2087400000000

General Configuration

Network accessMaximum Number of CPEsBaseline PrivacyDOCSIS ModeConfig file
Allowed
1
Enabled
3.1
cmreg-vmdg660-bbt076-b.cm

Primary Downstream Service Flow

SFIDMax Traffic RateMax Traffic BurstMin Traffic Rate
21894
1230000450 bps
42600bytes
0 bps

Primary Upstream Service Flow

SFIDMax Traffic RateMax Traffic BurstMin Traffic RateMax Concatenated BurstScheduling Type
21893
110000274 bps
42600bytes
0 bps
42600bytes
Best Effort

 

Any help would be much appreciated as the phone support seems to have no idea. 

21 Replies

  • Ash_'s avatar
    Ash_
    On our wavelength
    2 years ago

    Network Log

    Time Priority Description
    21-08-2024 22:52:07noticeGUI Login Status - Login Success from LAN interface
    21-08-2024 21:39:01noticeGUI Login Status - Login Success from LAN interface
    21-08-2024 21:01:59noticeREGISTRATION COMPLETE - Waiting for Operational status
    21-08-2024 21:01:55noticeUS 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;
    21-08-2024 21:01:50noticeDS 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;
    21-08-2024 21:01:49noticeTLV-11 - unrecognized OID;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
    21-08-2024 21:01:42warningDHCP WARNING - Non-critical field invalid in response ;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
    21-08-2024 21:01:40noticeHonoring MDD; IP provisioning mode = IPv4
    21-08-2024 21:01:18criticalSYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
    21-08-2024 21:01:17criticalCable Modem Reboot because of - Reboot UI
    21-08-2024 20:32:49criticalStarted Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
    21-08-2024 20:32:49critical16 consecutive T3 timeouts while trying to range on upstream channel 8;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
    21-08-2024 20:32:49criticalUnicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
    21-08-2024 20:32:25criticalStarted Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
    21-08-2024 20:31:41criticalStarted Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
    16-08-2024 06:22:47criticalNo Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
    15-08-2024 09:39:28criticalSYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
    15-08-2024 09:39:27criticalSYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
    15-08-2024 09:39:01criticalNo Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
    15-08-2024 09:38:48criticalSYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
    15-08-2024 09:38:47criticalSYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
    15-08-2024 09:38:43criticalSYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
    15-08-2024 09:33:34criticalSYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
    15-08-2024 09:33:00criticalSYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
    15-08-2024 09:33:00criticalCable Modem Reboot because of - Reboot Timezone Change
    15-08-2024 09:30:15criticalSYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
    15-08-2024 09:29:54criticalSYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
    15-08-2024 09:29:53criticalCable Modem Reboot because of - pin-reset
  • Ash_'s avatar
    Ash_
    On our wavelength
    2 years ago

    This morning the upload is much better but I have done nothing. The download is correct as I am running this speed test off my old Mac mini home server connected over 1gb ethernet into a switch. 

     

    My Macbook Pro using 2.5gb adaptor hit 1180mbs down and 105.3mbps up. 

    The speeds are just up and down all the time. 

  • Roger_Gooner's avatar
    Roger_Gooner
    Alessandro Volta
    2 years ago

    Although your stats look good the log shows network instability. Report this to VM again.

    • Ash_'s avatar
      Ash_
      On our wavelength
      2 years ago

      Hi mate,

      Thanks for this. This morning I did call VM and they are going to call me this evening as I mentioned sometimes it's good and most of the time it's poor.

      What points to the network instability so I can go back armed with that info? Is it "Unicast Maintenance Ranging attempted - No response - Retries exhausted"? 

      • -tony-'s avatar
        -tony-
        Alessandro Volta
        2 years ago

        and they are going to call me this evening

        well it will be a first if they do - its the way of getting rid of you and the agent closing the call as solved

        offshore was it - thats usual although it can happen if you happen to get someone in the UK - if they do call - go out and get a lottery ticket its sure to win as you are obviously special/unique

  • Anonymous's avatar
    Anonymous
    2 years ago

    The window (there is only one) is defined by DOCSIS to be 12 dB. Even in 4.0 it is still only 12 dB, which could be a bigger challenge, since the return path can span 5-684 MHz.

  • jpeg1's avatar
    jpeg1
    Alessandro Volta
    2 years ago

    That 6dB slope on downstream levels from the lowest to the highest frequencies is certainly consistent with a failing outside cable.