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Lavarinth's avatar
Lavarinth
Aspirant
Apr 23, 2021

CM1000 - Another Speed Drop Woe (From Gigabit/900Mbps to 400Mbps to 20Mbps)

Hi all. Just posting to see if I can get any assistance with my Netgear CM1000 cable modem. It was purchased in June of 2019, so nearing a two year life in two months. Over the past few months, I wou...
FURRYe38's avatar
FURRYe38
Guru - Experienced User
Apr 23, 2021

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. 
Be sure to power OFF the modem for 1 minute them back ON.
https://community.netgear.com/t5/Cable-Modems-Routers/General-info-and-Troubleshooting-for-Cable-Modems/m-p/1530376#M12853

Lavarinth's avatar
Lavarinth
Aspirant
Apr 23, 2021

Hi there FURRYe38 thank you so much for the input!

I can thankfully fill in that all those options have checked out per the tech's visit and a follow up call to customer support. I additionally called in after your post to verify if your suggestions and they confirmed these actions were confirmed and all were stable. There are also no splitters as verified by the tech and myself. The cable itself connected to their diagnostic device shows perfect reception of the service.

 

The extremely low Mbps did reappear again tonight and I'm currently typing with a 22Mbps connection versus the expected 800Mbps+. As soon as it hit, I went through with the modem reset as requested of one minute (or more) and the situation did not remedy from this. I did however, copy down the logs that were freshed in case this may be of any assitance. Again, this issue of low Mbps will "resolve itself" after 2-3 hours to a 250-400ish Mbps speed for the remainder of the night until the morning when it occurs again.

 

TimePriorityDescription
2021-04-23, 21:58:56Notice (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=3c:37:86:e9:1c:d8;CMTS-MAC=00:aa:6e:c1:05:d6;CM-QOS=1.1;CM-VER=3.1;
2021-04-23, 21:57:32Warning (5)Dynamic Range Window violation
2021-04-23, 21:57:32Warning (5)RNG-RSP CCAP Commanded Power Exceeds Value Corresponding to the Top of the DRW;CM-MAC=3c:37:86:e9:1c:d8;CMTS-MAC=00:aa:6e:c1:05:d6;CM-QOS=1.1;CM-VER=3.1;
2021-04-23, 21:57:32Warning (5)Dynamic Range Window violation
2021-04-23, 21:57:32Warning (5)RNG-RSP CCAP Commanded Power Exceeds Value Corresponding to the Top of the DRW;CM-MAC=3c:37:86:e9:1c:d8;CMTS-MAC=00:aa:6e:c1:05:d6;CM-QOS=1.1;CM-VER=3.1;
2021-04-23, 21:57:32Warning (5)Dynamic Range Window violation
2021-04-23, 21:57:32Warning (5)RNG-RSP CCAP Commanded Power Exceeds Value Corresponding to the Top of the DRW;CM-MAC=3c:37:86:e9:1c:d8;CMTS-MAC=00:aa:6e:c1:05:d6;CM-QOS=1.1;CM-VER=3.1;
2021-04-23, 21:57:32Warning (5)Dynamic Range Window violation
2021-04-23, 21:57:32Warning (5)RNG-RSP CCAP Commanded Power Exceeds Value Corresponding to the Top of the DRW;CM-MAC=3c:37:86:e9:1c:d8;CMTS-MAC=00:aa:6e:c1:05:d6;CM-QOS=1.1;CM-VER=3.1;
2021-04-23, 21:57:31Critical (3)No Ranging Response received - T3 time-out;CM-MAC=3c:37:86:e9:1c:d8;CMTS-MAC=00:aa:6e:c1:05:d6;CM-QOS=1.1;CM-VER=3.1;
2021-04-23, 21:57:31Warning (5)Dynamic Range Window violation
2021-04-23, 21:57:31Warning (5)RNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW;CM-MAC=3c:37:86:e9:1c:d8;CMTS-MAC=00:aa:6e:c1:05:d6;CM-QOS=1.1;CM-VER=3.1;
2021-04-23, 21:57:31Warning (5)Dynamic Range Window violation
2021-04-23, 21:57:31Warning (5)RNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW;CM-MAC=3c:37:86:e9:1c:d8;CMTS-MAC=00:aa:6e:c1:05:d6;CM-QOS=1.1;CM-VER=3.1;
2021-04-23, 21:57:26Notice (6)DS profile assignment change. DS Chan ID: 32; Previous Profile: ; New Profile: 1.;CM-MAC=3c:37:86:e9:1c:d8;CMTS-MAC=00:aa:6e:c1:05:d6;CM-QOS=1.1;CM-VER=3.1;
2021-04-23, 21:57:21Notice (6)TLV-11 - unrecognized OID;CM-MAC=3c:37:86:e9:1c:d8;CMTS-MAC=00:aa:6e:c1:05:d6;CM-QOS=1.1;CM-VER=3.1;
2021-04-23, 21:57:20Warning (5)ToD request sent- No Response received;CM-MAC=3c:37:86:e9:1c:d8;CMTS-MAC=00:aa:6e:c1:05:d6;CM-QOS=1.1;CM-VER=3.1;
2021-04-23, 21:57:20Warning (5)DHCP WARNING - Non-critical field invalid in response ;CM-MAC=3c:37:86:e9:1c:d8;CMTS-MAC=00:aa:6e:c1:05:d6;CM-QOS=1.1;CM-VER=3.1;
Time Not EstablishedNotice (6)Honoring MDD; IP provisioning mode = IPv4
Time Not EstablishedCritical (3)UCD invalid or channel unusable;CM-MAC=3c:37:86:e9:1c:d8;CMTS-MAC=00:aa:6e:c1:05:d6;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=3c:37:86:e9:1c:d8;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
2021-04-23, 21:53:28Critical (3)No Ranging Response received - T3 time-out;CM-MAC=3c:37:86:e9:1c:d8;CMTS-MAC=00:aa:6e:c1:05:d6;CM-QOS=1.1;CM-VER=3.1;
Time Not EstablishedCritical (3)UCD invalid or channel unusable;CM-MAC=3c:37:86:e9:1c:d8;CMTS-MAC=00:aa:6e:c1:05:d6;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=3c:37:86:e9:1c:d8;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;