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Internet Dropping Out Frequently (NetGear Modem/Router)

New Poster

Internet Dropping Out Frequently (NetGear Modem/Router)

I've been searching the internet for solutions to this problem and my patience is growing thin. I have a Netgear AC1900 Cabel/Modem Router (Model C7000v2) and am getting frequent outages of internet access lasting anywhere from 30s to 5-10m.

Here's the data people seem to want to see.

 

Please help; I'm close to ramming my head through the wall.

 

Downstream Bonded Channels
Channel Lock Status Modulation Channel ID Frequency Power SNR Correctables Uncorrectables
1 Locked QAM256 1 519000000 Hz 10.9 dBmV 42.6 dB 0 0
2 Locked QAM256 2 525000000 Hz 10.8 dBmV 42.4 dB 0 0
3 Locked QAM256 3 531000000 Hz 11.1 dBmV 42.8 dB 0 0
4 Locked QAM256 4 537000000 Hz 11.1 dBmV 42.8 dB 0 0
5 Locked QAM256 5 543000000 Hz 10.9 dBmV 42.7 dB 0 0
6 Locked QAM256 6 549000000 Hz 11 dBmV 42.7 dB 0 0
7 Locked QAM256 7 555000000 Hz 11 dBmV 42.4 dB 0 0
8 Locked QAM256 8 561000000 Hz 11.2 dBmV 42.5 dB 0 0
9 Locked QAM256 9 567000000 Hz 11.4 dBmV 42.9 dB 0 0
10 Locked QAM256 10 573000000 Hz 11.3 dBmV 42.8 dB 0 0
11 Locked QAM256 11 579000000 Hz 11.4 dBmV 42.9 dB 0 0
12 Locked QAM256 12 585000000 Hz 11.5 dBmV 42.9 dB 0 0
13 Locked QAM256 13 591000000 Hz 11.3 dBmV 42.9 dB 0 0
14 Locked QAM256 14 597000000 Hz 11.4 dBmV 42.9 dB 0 0
15 Locked QAM256 15 603000000 Hz 11.3 dBmV 42.9 dB 0 0
16 Locked QAM256 16 609000000 Hz 11.4 dBmV 43 dB 0 0
17 Not Locked Unknown 0 0 Hz 0.0 dBmV 0.0 dB 0 0
18 Not Locked Unknown 0 0 Hz 0.0 dBmV 0.0 dB 0 0
19 Not Locked Unknown 0 0 Hz 0.0 dBmV 0.0 dB 0 0
20 Not Locked Unknown 0 0 Hz 0.0 dBmV 0.0 dB 0 0
21 Not Locked Unknown 0 0 Hz 0.0 dBmV 0.0 dB 0 0
22 Not Locked Unknown 0 0 Hz 0.0 dBmV 0.0 dB 0 0
23 Not Locked Unknown 0 0 Hz 0.0 dBmV 0.0 dB 0 0
24 Not Locked Unknown 0 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 1 5120 Ksym/sec 35800000 Hz 37.8 dBmV
2 Locked ATDMA 2 5120 Ksym/sec 29400000 Hz 37.7 dBmV
3 Locked ATDMA 3 5120 Ksym/sec 23000000 Hz 37.6 dBmV
4 Not Locked Unknown 0 0 Ksym/sec 0 Hz 0.0 dBmV
5 Not Locked Unknown 0 0 Ksym/sec 0 Hz 0.0 dBmV
6 Not Locked Unknown 0 0 Ksym/sec 0 Hz 0.0 dBmV
7 Not Locked Unknown 0 0 Ksym/sec 0 Hz 0.0 dBmV
8 Not Locked Unknown 0 0 Ksym/sec 0 Hz 0.0 dBmV
 

 

Time Priority Description
1970-1-1, 00:00:38 Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=a0:40:a0:3b:84:d0;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0;
1970-1-1, 00:00:42 Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=a0:40:a0:3b:84:d0;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0;
1970-1-1, 00:01:01 Critical (3) SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=a0:40:a0:3b:84:d0;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0;
1970-1-1, 00:01:02 Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=a0:40:a0:3b:84:d0;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0;
1970-1-1, 00:01:03 Critical (3) SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=a0:40:a0:3b:84:d0;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0;
1970-1-1, 00:01:04 Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=a0:40:a0:3b:84:d0;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0;
1970-1-1, 00:01:16 Critical (3) SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=a0:40:a0:3b:84:d0;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0;
1970-1-1, 00:01:17 Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=a0:40:a0:3b:84:d0;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0;
1970-1-1, 00:01:37 Critical (3) No UCDs Received - Timeout;;CM-MAC=a0:40:a0:3b:84:d0;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0;
1970-1-1, 00:01:41 Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=a0:40:a0:3b:84:d0;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0;
2018-5-2, 23:27:37 Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=a0:40:a0:3b:84:d0;CMTS-MAC=58:97:bd:2e:a7:95;CM-QOS=1.0;CM-VER=3.0;
2018-5-2, 23:27:54 Critical (3) No UCDs Received - Timeout;;CM-MAC=a0:40:a0:3b:84:d0;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0;
2018-5-2, 23:27:58 Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=a0:40:a0:3b:84:d0;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0;
1970-1-1, 00:00:41 Notice (6) WiFi Interface [wl0] set to Channel 4 (Side-Band Channel:N/A) - Reason:INIT
1970-1-1, 00:00:41 Notice (6) WiFi Interface [wl1] set to Channel 40 (Side-Band Channel:N/A) - Reason:INIT
1970-1-1, 00:00:50 Notice (6) Honoring MDD; IP provisioning mode = IPv6
2018-5-3, 00:10:47 Warning (5) MDD message timeout;CM-MAC=a0:40:a0:3b:84:d0;CMTS-MAC=58:97:bd:2e:a7:95;CM-QOS=1.1;CM-VER=3.0;
2018-5-3, 00:10:47 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=a0:40:a0:3b:84:d0;CMTS-MAC=58:97:bd:2e:a7:95;CM-QOS=1.1;CM-VER=3.0;
2018-5-3, 00:10:47 Warning (5) MDD message timeout;CM-MAC=a0:40:a0:3b:84:d0;CMTS-MAC=58:97:bd:2e:a7:95;CM-QOS=1.1;CM-VER=3.0;
2018-5-3, 00:10:47 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=a0:40:a0:3b:84:d0;CMTS-MAC=58:97:bd:2e:a7:95;CM-QOS=1.1;CM-VER=3.0;
2018-5-3, 00:19:29 Notice (6) WiFi Interface [wl0] set to Channel 1 (Side-Band Channel:5) - Reason:GUI
2018-5-3, 00:19:32 Notice (6) WiFi Interface [wl1] set to Channel 108 (Side-Band Channel:N/A) - Reason:INTERFERENCE
2018-5-3, 00:19:33 Notice (6) WiFi Interface [wl0] set to Channel 1 (Side-Band Channel:N/A) - Reason:INTERFERENCE
Expert

Re: Internet Dropping Out Frequently (NetGear Modem/Router)

Your signal is too "hot", you'll want to knock the power levels down with an attenuator (AKA a pad). That may not be the only problem, but it's the first step.

 

Also...

I've asked an employee to check the CMTS for real-time and historical RF signal reports from your modem. They can also check your local node/plant for any degradation or error reports. You can expect a reply in this thread. 

 

Make sure you are troubleshooting via ethernet to eliminate WiFi as the culprit.

 

See the troubleshooting guide. If you would like help from the community, please post your equipment details (make/model of your modem/gateway/router) and a screenshot of your signal levels and your error/event log. Thank you!



"Keepin' it clean since '09"
I am not a Comcast employee, just a moderator.
Official Employee

Re: Internet Dropping Out Frequently (NetGear Modem/Router)

Hello lukeschrader. I can assist with troubleshooting your intermittent connectivity issue.  Please send me a private message and include your full name and account primary phone number so I can access your equipment.

New Poster

Re: Internet Dropping Out Frequently (NetGear Modem/Router)

I've ran an Ethernet cable to my desktop and the issue persists; so I know it's not WiFi.

I've had 2 techs come out, and a 3rd is coming out this Sunday. I'll mention the power levels to them but they noticed the neighborhood i live in has had trouble recently so they are most likely going to get a maintanence team involved to examine the hubs.

 

Thanks for the response though!

New Poster

Re: Internet Dropping Out Frequently (NetGear Modem/Router)

2018-5-6, 16:31:31 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=a0:40:a0:3b:84:d0;CMTS-MAC=58:97:bd:2e:a7:95;CM-QOS=1.1;CM-VER=3.0;
2018-5-6, 16:31:31 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=a0:40:a0:3b:84:d0;CMTS-MAC=58:97:bd:2e:a7:95;CM-QOS=1.1;CM-VER=3.0;
2018-5-6, 16:46:52 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=a0:40:a0:3b:84:d0;CMTS-MAC=58:97:bd:2e:a7:95;CM-QOS=1.1;CM-VER=3.0;
2018-5-6, 16:46:52 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=a0:40:a0:3b:84:d0;CMTS-MAC=58:97:bd:2e:a7:95;CM-QOS=1.1;CM-VER=3.0;
2018-5-6, 16:48:30 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=a0:40:a0:3b:84:d0;CMTS-MAC=58:97:bd:2e:a7:95;CM-QOS=1.1;CM-VER=3.0;
2018-5-6, 17:23:10 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=a0:40:a0:3b:84:d0;CMTS-MAC=58:97:bd:2e:a7:95;CM-QOS=1.1;CM-VER=3.0;
2018-5-6, 17:36:18 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=a0:40:a0:3b:84:d0;CMTS-MAC=58:97:bd:2e:a7:95;CM-QOS=1.1;CM-VER=3.0;
2018-5-6, 18:09:59 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=a0:40:a0:3b:84:d0;CMTS-MAC=58:97:bd:2e:a7:95;CM-QOS=1.1;CM-VER=3.0;
2018-5-6, 18:35:04 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=a0:40:a0:3b:84:d0;CMTS-MAC=58:97:bd:2e:a7:95;CM-QOS=1.1;CM-VER=3.0;
2018-5-6, 18:35:04 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=a0:40:a0:3b:84:d0;CMTS-MAC=58:97:bd:2e:a7:95;CM-QOS=1.1;CM-VER=3.0;
2018-5-6, 19:39:05 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=a0:40:a0:3b:84:d0;CMTS-MAC=58:97:bd:2e:a7:95;CM-QOS=1.1;CM-VER=3.0;
2018-5-6, 19:39:05 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=a0:40:a0:3b:84:d0;CMTS-MAC=58:97:bd:2e:a7:95;CM-QOS=1.1;CM-VER=3.0;
2018-5-6, 19:40:43 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=a0:40:a0:3b:84:d0;CMTS-MAC=58:97:bd:2e:a7:95;CM-QOS=1.1;CM-VER=3.0;
2018-5-6, 19:42:16 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=a0:40:a0:3b:84:d0;CMTS-MAC=58:97:bd:2e:a7:95;CM-QOS=1.1;CM-VER=3.0;
2018-5-6, 19:55:21 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=a0:40:a0:3b:84:d0;CMTS-MAC=58:97:bd:2e:a7:95;CM-QOS=1.1;CM-VER=3.0;
2018-5-6, 19:55:21 Critical (3)

Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=a0:40:a0:3b:84:d0;CMTS-MAC=58:97:bd:2e:a7:95;CM-QOS=1.1;CM-VER=3.0;

 

Here's some recent logs of today, where the internet has been going out 2-4 times per hour