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Frequent loss of internet, need for modem reboots

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Frequent Visitor

Frequent loss of internet, need for modem reboots

For the last week or so, I've lost internet several times a day.  Rebooting the modem with get it going again for anywhere from a few minutes to a few hours.

 

The modem log shows a lot of apparent errors.  Any ideas for next steps?

 

Status - Event Log

The table below contains the log of events that the SBG6580 has detected. This log can be important to the service provider to help diagnose and correct problems, if any should occur.

 
Time Priority Description
Mon Jun 15 05:54:04 2020 Warning (5) Unicast DSID PSN startup error
Mon Jun 15 05:53:38 2020 Notice (6) TLV-11 - unrecognized OID;CM-MAC=cc:7d:37:1c:14:30;CMTS-MAC=00:56:2b:77:d8:ee;CM-QOS=1.1;CM-VER=3.0;
Time Not Established Notice (6) Honoring MDD; IP provisioning mode = IPv6
Time Not Established Notice (6) WiFi Interface [wl0] set to Channel 1 (Side-Band Channel:N/A) - Reason:INIT
Mon Jun 15 05:50:08 2020 Critical (3) Resetting the cable modem due to docsDevResetNow
Sun Jun 14 22:32:44 2020 Critical (3) Resetting the cable modem due to docsDevResetNow
Sat Jun 13 06:41:55 2020 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=cc:7d:37:1c:14:30;CMTS-MAC=00:56:2b:77:d8:ee;CM-QOS=1.1;CM-VER=3.0;
Fri Jun 12 15:52:25 2020 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=cc:7d:37:1c:14:30;CMTS-MAC=00:56:2b:77:d8:ee;CM-QOS=1.1;CM-VER=3.0;
Fri Jun 12 15:38:40 2020 Critical (3) Resetting the cable modem due to docsDevResetNow
Fri Jun 12 13:38:04 2020 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=cc:7d:37:1c:14:30;CMTS-MAC=00:56:2b:77:d8:ee;CM-QOS=1.1;CM-VER=3.0;
Fri Jun 12 13:23:07 2020 Critical (3) TLV-11 - Illegal Set operation failed;CM-MAC=cc:7d:37:1c:14:30;CMTS-MAC=00:56:2b:77:d8:ee;CM-QOS=1.1;CM-VER=3.0;
Fri Jun 12 13:22:41 2020 Critical (3) No Ranging Response received - T3 time-out
Fri Jun 12 13:22:26 2020 Critical (3) No Maintenance Broadcasts for Ranging opportunities received - T2 time-out;CM-MAC=cc:7d:37:1c:14:30;CMTS-MAC=00:56:2b:77:d8:ee;CM-QOS=1.0;CM-VER=3.0;
Fri Jun 12 13:22:16 2020 Critical (3) No Ranging Response received - T3 time-out
Fri Jun 12 13:21:50 2020 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=cc:7d:37:1c:14:30;CMTS-MAC=00:56:2b:77:d8:ee;CM-QOS=1.1;CM-VER=3.0;
Fri Jun 12 13:03:15 2020 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=cc:7d:37:1c:14:30;CMTS-MAC=00:56:2b:77:d8:ee;CM-QOS=1.1;CM-VER=3.0;
Fri Jun 12 05:07:37 2020 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=cc:7d:37:1c:14:30;CMTS-MAC=00:56:2b:77:d8:ee;CM-QOS=1.1;CM-VER=3.0;
Fri Jun 12 04:53:47 2020 Critical (3) Resetting the cable modem due to docsDevResetNow
Thu Jun 11 06:58:54 2020 Critical (3) Resetting the cable modem due to docsDevResetNow
Thu Jun 11 06:50:01 2020 Critical (3) Resetting the cable modem due to docsDevResetNow
Thu Jun 11 06:21:17 2020 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=cc:7d:37:1c:14:30;CMTS-MAC=00:56:2b:77:d8:ee;CM-QOS=1.1;CM-VER=3.0;
Sat Jun 06 05:33:43 2020 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=cc:7d:37:1c:14:30;CMTS-MAC=00:56:2b:77:d8:ee;CM-QOS=1.1;CM-VER=3.0;
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Expert

Re: Frequent loss of internet, need for modem reboots

Please also post the *Downstream Power Level*, the *Upstream Power Level*, and the *SNR* (Signal to Noise Ratio) numbers.




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Frequent Visitor

Re: Frequent loss of internet, need for modem reboots

Downstream Bonded Channels
Channel Lock Status Modulation Channel ID Frequency Power SNR Corrected Uncorrectables
1 Locked QAM256 9 525000000 Hz 3.8 dBmV 40.2 dB 0 0
2 Locked QAM256 10 531000000 Hz 4.0 dBmV 40.4 dB 0 0
3 Locked QAM256 11 537000000 Hz 4.0 dBmV 39.9 dB 0 0
4 Locked QAM256 12 543000000 Hz 4.0 dBmV 40.1 dB 0 0
5 Locked QAM256 13 549000000 Hz 4.0 dBmV 40.0 dB 0 0
6 Locked QAM256 14 555000000 Hz 3.4 dBmV 40.2 dB 0 0
7 Locked QAM256 15 561000000 Hz 3.5 dBmV 40.1 dB 0 0
8 Locked QAM256 16 567000000 Hz 3.6 dBmV 39.9 dB 0 0

 

 
Upstream Bonded Channels
Channel Lock Status US Channel Type Channel ID Symbol Rate Frequency Power
1 Locked ATDMA 5 5120 Ksym/sec 38800000 Hz 44.0 dBmV
2 Locked ATDMA 6 5120 Ksym/sec 32400000 Hz 43.7 dBmV
3 Locked ATDMA 7 5120 Ksym/sec 26000000 Hz 43.7 dBmV
4 Locked ATDMA 8 5120 Ksym/sec 19600000 Hz 43.7 dBmV



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Expert

Re: Frequent loss of internet, need for modem reboots

Those are all within spec. Is this with a WiFi connection ? If so, for a test, does a computer hardwired directly to the 6580 with an ethernet cable have the same problem ?



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Frequent Visitor

Re: Frequent loss of internet, need for modem reboots

Usually I use WiFi, but as a test I disconnected all wifi devices, and hooked up one wired laptop.  I still lost internet  a few times a day, and also had the modem reboot itself.   Generally, but not always, if I lose internet connection, I can reboot the modem and when it comes up it will be OK for a while.

 

BTW, thank you so much for your help.  I really do appreciate it, and I know (from other fields) how frustrating intermittant problems are!

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Expert

Re: Frequent loss of internet, need for modem reboots

Even though the signal stats looked o/k at that snapshot in time, the error log entries confirm that something is going on. Perhaps there is noise ingress into the line(s) somewhere.

 

There are other signal stat figures that can't be read by the modem. They are the "Upstream Rx Power" (Upstream Receive Power Level), the "Upstream SNR Ch." (Upstream Signal To Noise Ratio), and the "Upstream ICFR" (In Channel Frequency Response). These are as equally important in diagnosing connectivity issues as are the modem's stats.


I'm going to escalate your issue to the Comcast corporate employees that are available to these boards. They can check the CMTS (Cable Modem Termination System) for any real time degradation and / or error reports, see your node / cable plant and modem health, and see whether or not everything is in the green zone. They can also see a history plot for the modem and poll for those upstream receive signal stats.

You should get a reply here in your topic. Good luck !



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Frequent Visitor

Re: Frequent loss of internet, need for modem reboots

Excellent, thank you again

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Official Employee

Re: Frequent loss of internet, need for modem reboots

Hi there, Markg777. Thanks for posting here in the community! I would be glad to step in and help you out with the internet troubles you've been experiencing. I can pull up some diagnostic reports on our end here and we can see how those compare to the information you provided and the symptoms you're experiencing. We will go from there. To start, please send me a PM with your first and last name.

 

To send a private message, please click my name "ComcastMorgan" then select "Send a Message" on the right side.

 

 

I will reply from there. Thanks!


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Re: Frequent loss of internet, need for modem reboots

 

Thank you for your help.  I wanted to pass along the resolution to problems.  Short answer is that it’s all good now.

 

I really appreciate the info that things were fine on the comcast side, and that levels and noise looked ok at my modem.

 

Having four people critically dependent professionally on reliable internet, I simply did an end to end upgrade and modernization.  I could not afford the downtime of extensive debugging.

 

My modem/router was 12 years old, and wired through 40+ feet of 35+ year old coax through the walls through 2 splitters. I replace all that with a new router right as the cable enters the house, 20 feet of CAT 6 ethernet cable to the first of three eero pro mesh routers.   I’m getting good speed and perfect reliability.

 

Thanks again for your thoughtful help!