CBR750 random disconnects

[Retired_Member]

I have just the one CBR750 modem/router - no additional satellites, etc. Nearly every day at random times, I'll get disconnected and have to reboot the device.

I've tried reflashing the firmware (currently on V4.6.5.8_2.0.54), changed the 2.4 Ghz channel to 6, reset to factory settings and still getting the same results. My thinking is it's something with the line coming into the house (I have Xfinity). I don't have any splitters connected to the Coax. Any thoughts or suggestions or should I have Xfinity send a tech out to investigate?

I'm attaching my Event Log as well as the cable connection log.

Time	Priority	Description
Apr 11 2022 13:28:09	Notice (6)	TLV-11 - unrecognized OID
Apr 11 2022 13:28:09	Notice (6)	TLV-11 - unrecognized OID
Apr 11 2022 13:28:09	Notice (6)	TLV-11 - unrecognized OID
Apr 11 2022 13:28:09	Notice (6)	TLV-11 - unrecognized OID
Apr 11 2022 13:28:09	Notice (6)	TLV-11 - unrecognized OID
Apr 11 2022 13:28:09	Notice (6)	TLV-11 - unrecognized OID
Apr 11 2022 13:28:09	Notice (6)	TLV-11 - unrecognized OID
Apr 11 2022 13:28:09	Notice (6)	TLV-11 - unrecognized OID
Apr 11 2022 13:28:09	Critical (3)	Config File Rejected due to Invalid or Unexpected TLV 11
Apr 11 2022 13:28:26	Alert (2)	CM Certificate Error
Apr 11 2022 13:28:35	Notice (6)	CM-STATUS message sent. Event Type Code: 16
Time Not Established	Critical (3)	No Ranging Response received - T3 time-out
Apr 11 2022 13:31:43	Warning (5)	MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1
Apr 11 2022 13:31:43	Notice (6)	TLV-11 - unrecognized OID
Apr 11 2022 13:31:43	Critical (3)	Config File Rejected due to Invalid or Unexpected TLV 11
Apr 11 2022 13:31:54	Warning (5)	RCS Partial Service
Apr 11 2022 13:32:03	Notice (6)	CM-STATUS message sent. Event Type Code: 23
Apr 11 2022 13:32:03	Alert (2)	CM Certificate Error
Apr 11 2022 13:32:08	Notice (6)	CM-STATUS message sent. Event Type Code: 16
Apr 11 2022 14:38:27	Alert (2)	CM Certificate Error
Apr 11 2022 14:47:27	Notice (6)	DS profile config update. DS Chan ID: 37.
Apr 11 2022 14:47:30	Notice (6)	CM-STATUS message sent. Event Type Code: 16
Apr 11 2022 14:48:56	Notice (6)	DS profile config update. DS Chan ID: 37.
Apr 11 2022 14:49:02	Notice (6)	CM-STATUS message sent. Event Type Code: 23
Apr 11 2022 14:50:23	Notice (6)	DS profile config update. DS Chan ID: 37.
Apr 11 2022 14:50:32	Notice (6)	CM-STATUS message sent. Event Type Code: 24
Time Not Established	Critical (3)	No Ranging Response received - T3 time-out
Apr 11 2022 15:04:38	Warning (5)	MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1
Apr 11 2022 15:04:38	Notice (6)	TLV-11 - unrecognized OID
Apr 11 2022 15:04:38	Critical (3)	Config File Rejected due to Invalid or Unexpected TLV 11
Apr 11 2022 15:04:54	Alert (2)	CM Certificate Error
Apr 11 2022 15:04:57	Notice (6)	CM-STATUS message sent. Event Type Code: 2
Apr 11 2022 19:28:21	Warning (5)	Lost MDD Timeout
Apr 11 2022 19:28:27	Notice (6)	CM-STATUS message sent. Event Type Code: 23
Apr 12 2022 06:40:07	Notice (6)	DS profile config update. DS Chan ID: 37.
Apr 12 2022 06:40:12	Notice (6)	CM-STATUS message sent. Event Type Code: 24
Apr 12 2022 06:41:39	Notice (6)	DS profile config update. DS Chan ID: 37.
Apr 12 2022 06:41:46	Notice (6)	CM-STATUS message sent. Event Type Code: 2
Apr 12 2022 11:28:57	Warning (5)	Lost MDD Timeout
Apr 12 2022 11:28:58	Notice (6)	CM-STATUS message sent. Event Type Code: 24
Time Not Established	Critical (3)	No Ranging Response received - T3 time-out
Time Not Established	Warning (5)	RNG-RSP CCAP Commanded Power Exceeds Value Corresponding to the Top of the DRW
Apr 12 2022 12:05:56	Warning (5)	MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1
Apr 12 2022 12:05:56	Notice (6)	TLV-11 - unrecognized OID
Apr 12 2022 12:05:56	Critical (3)	Config File Rejected due to Invalid or Unexpected TLV 11
Apr 12 2022 12:06:15	Alert (2)	CM Certificate Error
Apr 12 2022 12:06:20	Notice (6)	CM-STATUS message sent. Event Type Code: 5

[FURRYe38]

What FW is loaded on the CBR? 

I see some Config File Rejected due to Invalid or Unexpected TLV 11 entries that the ISP needs to look in to.

Please post a copy and paste of the modems connection status page.
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 then back ON.
https://community.netgear.com/t5/Cable-Modems-Routers/General-info-and-Troubleshooting-for-Cable-Mod...
https://kb.netgear.com/24311/Power-level-guidelines-for-a-NETGEAR-cable-modem-router?article=24311
https://www.duckware.com/tech/solving-intermittent-cable-modem-issues.html

[Retired_Member]

Firmware is V4.6.5.8_2.0.54

Startup Procedure

Procedure Status Comment Acquire Downstream Channel 507000000 Hz Locked Connectivity State Ok Operational Boot State Ok Operational Security Enabled BPI+ IP Provisioning Mode Honor MDD honorMdd(4)

Downstream Bonded Channels

Channel Lock Status Modulation Channel ID Frequency Power SNR Correctables Uncorrectable 1 Locked QAM 256 2 489000000 Hz -11.5 dBmV 36.6 dB 3 0 2 Locked QAM 256 3 495000000 Hz -11.7 dBmV 36.3 dB 2 0 3 Locked QAM 256 4 501000000 Hz -11.4 dBmV 36.3 dB 0 0 4 Locked QAM 256 5 507000000 Hz -11.7 dBmV 36.3 dB 2 0 5 Locked QAM 256 6 513000000 Hz -11.5 dBmV 35.5 dB 0 0 6 Locked QAM 256 7 519000000 Hz -11.9 dBmV 36.3 dB 0 0 7 Locked QAM 256 8 525000000 Hz -12.2 dBmV 35.5 dB 0 0 8 Locked QAM 256 9 531000000 Hz -12.2 dBmV 35.0 dB 0 0 9 Locked QAM 256 10 537000000 Hz -12.5 dBmV 34.9 dB 0 0 10 Locked QAM 256 11 543000000 Hz -12.5 dBmV 35.5 dB 0 0 11 Locked QAM 256 12 549000000 Hz -13.2 dBmV 34.7 dB 0 0 12 Locked QAM 256 13 555000000 Hz -13.0 dBmV 35.5 dB 0 0 13 Locked QAM 256 14 561000000 Hz -13.3 dBmV 35.0 dB 0 0 14 Locked QAM 256 15 567000000 Hz -12.7 dBmV 35.7 dB 0 0 15 Locked QAM 256 16 573000000 Hz -13.3 dBmV 34.0 dB 0 0 16 Locked QAM 256 17 579000000 Hz -13.5 dBmV 34.3 dB 0 0 17 Locked QAM 256 18 585000000 Hz -13.5 dBmV 35.0 dB 0 0 18 Locked QAM 256 19 591000000 Hz -13.7 dBmV 33.8 dB 0 0 19 Locked QAM 256 20 597000000 Hz -13.7 dBmV 34.3 dB 0 0 20 Locked QAM 256 21 603000000 Hz -14.3 dBmV 34.9 dB 7 0 21 Locked QAM 256 22 609000000 Hz -14.3 dBmV 34.4 dB 0 0 22 Locked QAM 256 23 615000000 Hz -14.8 dBmV 34.4 dB 11 0 23 Locked QAM 256 24 621000000 Hz -14.0 dBmV 34.3 dB 7 0 24 Locked QAM 256 25 627000000 Hz -14.0 dBmV 33.9 dB 2 0 25 Locked QAM 256 26 633000000 Hz -14.0 dBmV 34.4 dB 1 0 26 Locked QAM 256 27 639000000 Hz -14.4 dBmV 34.3 dB 0 0 27 Locked QAM 256 28 645000000 Hz -15.7 dBmV 33.4 dB 0 0 28 Locked QAM 256 29 651000000 Hz -15.8 dBmV 33.3 dB 0 0 29 Locked QAM 256 30 657000000 Hz -16.0 dBmV 33.0 dB 0 0 30 Locked QAM 256 31 663000000 Hz -16.4 dBmV 32.9 dB 2 0 31 Locked QAM 256 32 669000000 Hz -16.0 dBmV 32.9 dB 11441 36263 32 Not Locked N/A N/A 0 Hz 0.0 dBmV 0.0 dB 0 0

Upstream Bonded Channels

Channel Lock Status US Channel Type Channel ID Symbol Rate Frequency Power 1 Locked ATDMA 4 5120 Ksym/sec 16400000 Hz 45.0 dBmV 2 Locked ATDMA 3 5120 Ksym/sec 22800000 Hz 46.0 dBmV 3 Locked ATDMA 2 5120 Ksym/sec 29200000 Hz 46.5 dBmV 4 Locked ATDMA 1 5120 Ksym/sec 35600000 Hz 46.3 dBmV 5 Locked ATDMA 5 2560 Ksym/sec 40400000 Hz 47.0 dBmV 6 Not Locked N/A Unknown 0 Ksym/sec 0 Hz 0.0 dBmV 7 Not Locked N/A Unknown 0 Ksym/sec 0 Hz 0.0 dBmV 8 Not Locked N/A Unknown 0 Ksym/sec 0 Hz 0.0 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 1 Locked 3 37 690000000 Hz -15.5 dBmV 32.5 dB 1108~2987 0 0 0 2 Not Locked 0 0 0 Hz 0.0 dBmV 0.0 dB 0~4095 0 0 0

Upstream OFDMA Channels

Channel Lock Status Modulation/Profile ID Channel ID Frequency Power 1 Not Locked 0 0 0 Hz 0.0 dBmV 2 Not Locked 0 0 0 Hz 0.0 dBmV

[FURRYe38]

For one the power levels are too low:

https://kb.netgear.com/24311/Power-level-guidelines-for-a-NETGEAR-cable-modem-router?article=24311

Something that the ISP needs to check on. 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. 

[Retired_Member]

Thanks for the replies. Last night I checked behind the wall plate where the line is coming into the house. There was an old splitter and a kinked coax cable, which goes directly to the modem. I replaced the splitter and coax and I'm seeing a huge improvement in the power levels. Still not ideal, but much closer to normal ranges. So far no disconnects and the event log is clean, but I'll give it another few days to see how things look.

Startup Procedure

Procedure Status Comment Acquire Downstream Channel 507000000 Hz Locked Connectivity State Ok Operational Boot State Ok Operational Security Enabled BPI+ IP Provisioning Mode Honor MDD honorMdd(4)

Downstream Bonded Channels

Channel Lock Status Modulation Channel ID Frequency Power SNR Correctables Uncorrectable 1 Locked QAM 256 2 489000000 Hz -5.5 dBmV 38.6 dB 5 0 2 Locked QAM 256 3 495000000 Hz -6.0 dBmV 38.6 dB 0 0 3 Locked QAM 256 4 501000000 Hz -6.0 dBmV 38.9 dB 0 0 4 Locked QAM 256 5 507000000 Hz -6.2 dBmV 38.6 dB 0 0 5 Locked QAM 256 6 513000000 Hz -5.9 dBmV 38.9 dB 0 0 6 Locked QAM 256 7 519000000 Hz -6.2 dBmV 38.9 dB 0 0 7 Locked QAM 256 8 525000000 Hz -6.5 dBmV 38.9 dB 0 0 8 Locked QAM 256 9 531000000 Hz -6.9 dBmV 38.6 dB 0 0 9 Locked QAM 256 10 537000000 Hz -7.0 dBmV 38.6 dB 0 0 10 Locked QAM 256 11 543000000 Hz -6.7 dBmV 38.6 dB 0 0 11 Locked QAM 256 12 549000000 Hz -7.4 dBmV 38.6 dB 0 0 12 Locked QAM 256 13 555000000 Hz -7.2 dBmV 38.6 dB 0 0 13 Locked QAM 256 14 561000000 Hz -7.5 dBmV 38.6 dB 0 0 14 Locked QAM 256 15 567000000 Hz -7.2 dBmV 38.6 dB 0 0 15 Locked QAM 256 16 573000000 Hz -7.5 dBmV 38.9 dB 0 0 16 Locked QAM 256 17 579000000 Hz -7.7 dBmV 37.6 dB 0 0 17 Locked QAM 256 18 585000000 Hz -7.5 dBmV 38.6 dB 0 0 18 Locked QAM 256 19 591000000 Hz -8.0 dBmV 38.2 dB 0 0 19 Locked QAM 256 20 597000000 Hz -7.7 dBmV 37.6 dB 1 0 20 Locked QAM 256 21 603000000 Hz -8.4 dBmV 38.6 dB 0 0 21 Locked QAM 256 22 609000000 Hz -8.4 dBmV 37.3 dB 0 0 22 Locked QAM 256 23 615000000 Hz -8.7 dBmV 37.6 dB 0 0 23 Locked QAM 256 24 621000000 Hz -8.5 dBmV 37.6 dB 3 0 24 Locked QAM 256 25 627000000 Hz -8.4 dBmV 37.6 dB 19 36 25 Locked QAM 256 26 633000000 Hz -8.5 dBmV 37.6 dB 8 41 26 Locked QAM 256 27 639000000 Hz -8.7 dBmV 37.6 dB 8 43 27 Locked QAM 256 28 645000000 Hz -9.5 dBmV 37.6 dB 6 45 28 Locked QAM 256 29 651000000 Hz -9.9 dBmV 37.3 dB 6 45 29 Locked QAM 256 30 657000000 Hz -10.4 dBmV 37.3 dB 6 43 30 Locked QAM 256 31 663000000 Hz -10.7 dBmV 36.6 dB 10 41 31 Locked QAM 256 32 669000000 Hz -10.2 dBmV 36.6 dB 19 36 32 Not Locked N/A N/A 0 Hz 0.0 dBmV 0.0 dB 0 0

Upstream Bonded Channels

Channel Lock Status US Channel Type Channel ID Symbol Rate Frequency Power 1 Locked ATDMA 4 5120 Ksym/sec 16400000 Hz 40.5 dBmV 2 Locked ATDMA 3 5120 Ksym/sec 22800000 Hz 40.8 dBmV 3 Locked ATDMA 2 5120 Ksym/sec 29200000 Hz 41.0 dBmV 4 Locked ATDMA 1 5120 Ksym/sec 35600000 Hz 41.8 dBmV 5 Locked ATDMA 5 2560 Ksym/sec 40400000 Hz 42.0 dBmV 6 Not Locked N/A Unknown 0 Ksym/sec 0 Hz 0.0 dBmV 7 Not Locked N/A Unknown 0 Ksym/sec 0 Hz 0.0 dBmV 8 Not Locked N/A Unknown 0 Ksym/sec 0 Hz 0.0 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 1 Locked 3 37 690000000 Hz -9.5 dBmV 37.7 dB 1108~2987 0 0 0 2 Not Locked 0 0 0 Hz 0.0 dBmV 0.0 dB 0~4095 0 0 0

Upstream OFDMA Channels

Channel Lock Status Modulation/Profile ID Channel ID Frequency Power 1 Not Locked 0 0 0 Hz 0.0 dBmV 2 Not Locked 0 0 0 Hz 0.0 dBmV

[FURRYe38]

Ok. Levels are a bit to low now. Might ask the ISP for tech to visit on site if you seem to continue to have problems. If we can get the power levels to a happy mid spot would be preferred.