NETGEAR is aware of a growing number of phone and online scams. To learn how to stay safe click here.

Forum Discussion

hubbles_law's avatar
hubbles_law
Aspirant
Dec 15, 2022

CM1200 losing speed right after reboot

Background - about 48 hours ago, I noticed my internet slow down and struggling. Since then whenever I run a speed test I wind up with ~30Mbps Down | ~20Mbps Up and should be around 1Gbps Down, I called up RCN.

 

I moved the modem closer to the wall and tested it hardlined to the computer.  I performed countless reboots and a few factory resets.  While looking over http://il.speedtest.rcn.net/merlin/ - I see:

The modem is operating in Partial mode. This may negatively impact service and could indicate a problem with one or more Upstream or Downstream channels.

Last Connection Status: Partially operational

OFDM impairment. Channel disabled by modem.

 

I only see 20 of 32 Down Channels locked, and on the event log under 192.168.100.1 I have noticed event code 20 and 22 seem to populate regularly.

 

NOW - the strange part.  Whenever I reboot the modem, after it connects to the internet I can run a speed test and will see around 1Gbps down for the first minute or so if I run multiple tests back to back.  But then it starts to drop and eventually settles back around ~30Mbps... I can recreate this behavior multiple times but the slow down doesn't seem to happen at the same intervals, at least not from what I can tell.

 

I just spent 4 hours with the service tech who checked all the lines, decided to replace the line to the house, and told me they are seeing everything from their end working just fine. After they did so I am seeing better power but the problem persists for my Netgear CM1200. They even tested their Hiltron CODA-5712 which seemed to be steady for around 15m with 1Gbps down speeds. So my ISP is saying its a problem with my modem.

Which is on firmware V3.02.01 which should be what they are using.

 

Has anyone seen anything like this? Is my 2 year old modem hardware failing?

8 Replies

Replies have been turned off for this discussion
  • FURRYe38's avatar
    FURRYe38
    Guru - Experienced User

     


    Please post a copy and paste of the modems connection status and event log page.
    https://kb.netgear.com/30007/How-do-I-obtain-the-cable-connection-information-from-a-NETGEAR-cable-modem-modem-router
    https://kb.netgear.com/30008/How-do-I-view-or-clear-the-event-logs-on-my-NETGEAR-cable-modem-or-modem-router

     

    Be sure your using a good quality LAN cable between the modem and router. CAT6 is recommended. 
    What is the brand and model of the host wifi router connected to the modem?

     

    Have the ISP check the signal and line quality UP to the modem. Be sure the ISP provisions the modem correctly.
    Be sure there are no coax cable line splitters in the between the modem and ISP service box. 
    Be sure your using good quality RG6 coax cable up to the modem. 
    Start with removing any amplifiers, signal attenuators, or splitters from the coax.
    From there check the line for kinks, damage, moisture in the line.
    Check the connectors for improperly made ends, foil touching the copper coax line, loose connections, bad/old/cheap connectors, or corroded connections. Replace them if you do.
    Be sure to power OFF the modem for 1 minute then back ON.
    https://community.netgear.com/t5/Cable-Modems-Routers/General-info-and-Troubleshooting-for-Cable-Modems/m-p/1530376#M12853
    https://kb.netgear.com/24311/Power-level-guidelines-for-a-NETGEAR-cable-modem-router
    https://www.duckware.com/tech/solving-intermittent-cable-modem-issues.html

    • hubbles_law's avatar
      hubbles_law
      Aspirant

      Thanks for the reply, here are the details:

       

      Enable Extended Upstream Transmit Power is Unchecked

      Ethernet Port Aggregation is DISABLED

       

      Startup Procedure
      Procedure Status Comment
      Acquire Downstream Channel603000000 HzLocked
      Connectivity StateOKOperational
      Boot StateOKOperational
      SecurityEnabledBPI+
      IP Provisioning ModeHonor MDDhonorMdd(4)
       
      Downstream Bonded Channels (Partial Service)
      Channel Lock Status Modulation Channel ID Frequency Power SNR Correctables Uncorrectables
      1LockedQAM25615603000000 Hz1.6 dBmV39.4 dB00
      2LockedQAM2561519000000 Hz1.6 dBmV39.7 dB00
      3LockedQAM2562525000000 Hz1.6 dBmV39.6 dB00
      4LockedQAM2563531000000 Hz1.7 dBmV39.6 dB00
      5LockedQAM2564537000000 Hz1.8 dBmV39.7 dB00
      6LockedQAM2565543000000 Hz1.6 dBmV39.7 dB00
      7LockedQAM2566549000000 Hz1.5 dBmV39.7 dB00
      8LockedQAM2567555000000 Hz1.2 dBmV39.6 dB00
      9LockedQAM2568561000000 Hz1.5 dBmV38.9 dB00
      10LockedQAM2569567000000 Hz1.1 dBmV39.5 dB00
      11LockedQAM25610573000000 Hz1.1 dBmV39.1 dB00
      12LockedQAM25611579000000 Hz1.4 dBmV39.5 dB00
      13LockedQAM25612585000000 Hz1.1 dBmV39.4 dB00
      14LockedQAM25613591000000 Hz1.3 dBmV39.4 dB00
      15LockedQAM25614597000000 Hz1.6 dBmV39.5 dB00
      16LockedQAM25616609000000 Hz1.2 dBmV39.3 dB00
      17LockedQAM25617495000000 Hz0.6 dBmV39.6 dB00
      18LockedQAM25618501000000 Hz0.6 dBmV39.5 dB00
      19LockedQAM25619507000000 Hz1 dBmV39.5 dB00
      20LockedQAM25620513000000 Hz1.2 dBmV39.6 dB00
      21Not LockedUnknown00 Hz0.0 dBmV0.0 dB00
      22Not LockedUnknown00 Hz0.0 dBmV0.0 dB00
      23Not LockedUnknown00 Hz0.0 dBmV0.0 dB00
      24Not LockedUnknown00 Hz0.0 dBmV0.0 dB00
      25Not LockedUnknown00 Hz0.0 dBmV0.0 dB00
      26Not LockedUnknown00 Hz0.0 dBmV0.0 dB00
      27Not LockedUnknown00 Hz0.0 dBmV0.0 dB00
      28Not LockedUnknown00 Hz0.0 dBmV0.0 dB00
      29Not LockedUnknown00 Hz0.0 dBmV0.0 dB00
      30Not LockedUnknown00 Hz0.0 dBmV0.0 dB00
      31Not LockedUnknown00 Hz0.0 dBmV0.0 dB00
      32Not LockedUnknown00 Hz0.0 dBmV0.0 dB00
       
      Upstream Bonded Channels
      Channel Lock Status US Channel Type Channel ID Symbol Rate Frequency Power
      1LockedATDMA15120 Ksym/sec36800000 Hz50.5 dBmV
      2LockedATDMA25120 Ksym/sec30350000 Hz50.8 dBmV
      3LockedATDMA35120 Ksym/sec23900000 Hz50.8 dBmV
      4Not LockedUnknown00 Ksym/sec0 Hz0.0 dBmV
      5Not LockedUnknown00 Ksym/sec0 Hz0.0 dBmV
      6Not LockedUnknown00 Ksym/sec0 Hz0.0 dBmV
      7Not LockedUnknown00 Ksym/sec0 Hz0.0 dBmV
      8Not LockedUnknown00 Ksym/sec0 Hz0.0 dBmV
       
      Downstream OFDM Channels
      Channel Lock
      Status
      Modulation /
      Profile ID
      Channel
      ID
      Frequency Power SNR /
      MER
      Active Subcarrier
      Number Range
      Unerrored
      Codewords
      Correctable
      Codewords
      Uncorrectable
      Codewords
      1Not Locked000 Hz0 dBmV0.0 dB0 ~ 4095000
      2Not Locked000 Hz0 dBmV0.0 dB0 ~ 4095000
       
      Upstream OFDMA Channels
      Channel Lock Status Modulation / Profile ID Channel ID Frequency Power
      1Not Locked000 Hz0 dBmV
      2Not Locked000 Hz0 dBmV

       

       

      Time Priority Description
      Thu Dec 15 01:13:13 2022Notice (6)CM-STATUS message sent. Event Type Code: 22; Chan ID: 159; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=08:36:c9:a0:db:28;CMTS-MAC=00:ca:e5:c8:c8:ea;CM-QOS=1.1;CM-VER=3.1;
      Thu Dec 15 01:12:09 2022Notice (6)CM-STATUS message sent. Event Type Code: 20; Chan ID: 159; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=08:36:c9:a0:db:28;CMTS-MAC=00:ca:e5:c8:c8:ea;CM-QOS=1.1;CM-VER=3.1;
      Thu Dec 15 01:12:07 2022Notice (6)CM-STATUS message sent. Event Type Code: 5; Chan ID: 159; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=08:36:c9:a0:db:28;CMTS-MAC=00:ca:e5:c8:c8:ea;CM-QOS=1.1;CM-VER=3.1;
      Thu Dec 15 01:11:56 2022Warning (5)REG-RSP-MP Mismatch Between Calculated Value for P1.6hi Compared to CCAP Provided Value;CM-MAC=08:36:c9:a0:db:28;CMTS-MAC=00:ca:e5:c8:c8:ea;CM-QOS=1.1;CM-VER=3.1;
      Thu Dec 15 01:11:53 2022Notice (6)DS profile assignment change. DS Chan ID: 32; Previous Profile: ; New Profile: 1 2 3.;CM-MAC=08:36:c9:a0:db:28;CMTS-MAC=00:ca:e5:c8:c8:ea;CM-QOS=1.1;CM-VER=3.1;
      Thu Dec 15 01:11:49 2022Notice (6)TLV-11 - unrecognized OID;CM-MAC=08:36:c9:a0:db:28;CMTS-MAC=00:ca:e5:c8:c8:ea;CM-QOS=1.1;CM-VER=3.1;
      Thu Dec 15 01:11:48 2022Error (4)Missing BP Configuration Setting TLV Type: 17.9;CM-MAC=08:36:c9:a0:db:28;CMTS-MAC=00:ca:e5:c8:c8:ea;CM-QOS=1.1;CM-VER=3.1;
      Thu Dec 15 01:11:48 2022Error (4)Missing BP Configuration Setting TLV Type: 17.8;CM-MAC=08:36:c9:a0:db:28;CMTS-MAC=00:ca:e5:c8:c8:ea;CM-QOS=1.1;CM-VER=3.1;
      Thu Dec 15 01:11:48 2022Error (4)Missing BP Configuration Setting TLV Type: 17.7;CM-MAC=08:36:c9:a0:db:28;CMTS-MAC=00:ca:e5:c8:c8:ea;CM-QOS=1.1;CM-VER=3.1;
      Thu Dec 15 01:11:48 2022Error (4)Missing BP Configuration Setting TLV Type: 17.6;CM-MAC=08:36:c9:a0:db:28;CMTS-MAC=00:ca:e5:c8:c8:ea;CM-QOS=1.1;CM-VER=3.1;
      Thu Dec 15 01:11:48 2022Error (4)Missing BP Configuration Setting TLV Type: 17.5;CM-MAC=08:36:c9:a0:db:28;CMTS-MAC=00:ca:e5:c8:c8:ea;CM-QOS=1.1;CM-VER=3.1;
      Thu Dec 15 01:11:48 2022Error (4)Missing BP Configuration Setting TLV Type: 17.4;CM-MAC=08:36:c9:a0:db:28;CMTS-MAC=00:ca:e5:c8:c8:ea;CM-QOS=1.1;CM-VER=3.1;
      Thu Dec 15 01:11:48 2022Error (4)Missing BP Configuration Setting TLV Type: 17.3;CM-MAC=08:36:c9:a0:db:28;CMTS-MAC=00:ca:e5:c8:c8:ea;CM-QOS=1.1;CM-VER=3.1;
      Thu Dec 15 01:11:48 2022Error (4)Missing BP Configuration Setting TLV Type: 17.2;CM-MAC=08:36:c9:a0:db:28;CMTS-MAC=00:ca:e5:c8:c8:ea;CM-QOS=1.1;CM-VER=3.1;
      Thu Dec 15 01:11:48 2022Error (4)Missing BP Configuration Setting TLV Type: 17.1;CM-MAC=08:36:c9:a0:db:28;CMTS-MAC=00:ca:e5:c8:c8:ea;CM-QOS=1.1;CM-VER=3.1;
      Thu Dec 15 01:11:47 2022Warning (5)DHCP WARNING - Non-critical field invalid in response ;CM-MAC=08:36:c9:a0:db:28;CMTS-MAC=00:ca:e5:c8:c8:ea;CM-QOS=1.1;CM-VER=3.1;
      Time Not EstablishedNotice (6)Honoring MDD; IP provisioning mode = IPv4
      Time Not EstablishedCritical (3)No Ranging Response received - T3 time-out;CM-MAC=08:36:c9:a0:db:28;CMTS-MAC=00:ca:e5:c8:c8:ea;CM-QOS=1.1;CM-VER=3.1;
      Time Not EstablishedCritical (3)SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=08:36:c9:a0:db:28;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
      • FURRYe38's avatar
        FURRYe38
        Guru - Experienced User

        You have lots of errors and criticals that the ISP needs to review and resolve. 

         

        Be sure to have them check the other suggestions as well.