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Random internet drops

Regular Visitor

Random internet drops

I have a Netgear CM-1000 Cable Modem and I get random internet drops. I tried disconnecting every device from my router to make sure none of those were the cause of my problems, but yet the issue keeps happening. I thought that maybe my cable modem was bad, so I bought a new one and tried that for a couple of weeks. The same dropouts occurred. I returned the new modem and switch back to my old one.

 

I looked at my cable modem's log and found this message with both the old and new modem:

Warning (5) RNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW

I have a feeling that there is a problem with the wiring into my house. Only one two-way splitter is between the entry point and my cable modem. I tried replacing it, but the problem still exists. Also, I feel that it is important to note that nothing is connected to the second connection of the splitter.

Expert

Re: Random internet drops

Please also post the modem's signal stats. 

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




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Regular Visitor

Re: Random internet drops

<tabindex=-1>Downstream Bonded Channels</tabindex=-1>
Channel Lock Status Modulation Channel ID Frequency Power SNR / MER Unerrored Codewords Correctable Codewords Uncorrectable Codewords
1 Locked QAM256 32 669000000 Hz -3.6 dBmV 40.8 dB 738103994 16 90
2 Locked QAM256 1 483000000 Hz -0.7 dBmV 43.0 dB 670933577 30 123
3 Locked QAM256 2 489000000 Hz -0.4 dBmV 43.3 dB 670941467 24 129
4 Locked QAM256 3 495000000 Hz -0.4 dBmV 43.1 dB 670949775 29 115
5 Locked QAM256 4 501000000 Hz -0.5 dBmV 42.7 dB 670958186 26 110
6 Locked QAM256 5 507000000 Hz -0.8 dBmV 42.9 dB 670966096 33 116
7 Locked QAM256 6 513000000 Hz -0.6 dBmV 42.8 dB 670973897 25 126
8 Locked QAM256 7 519000000 Hz -0.5 dBmV 43.1 dB 670982994 32 114
9 Locked QAM256 8 525000000 Hz -0.9 dBmV 42.9 dB 590713280 32 116
10 Locked QAM256 9 531000000 Hz -0.9 dBmV 42.9 dB 590724457 30 112
11 Locked QAM256 10 537000000 Hz -1.1 dBmV 42.8 dB 590735547 25 124
12 Locked QAM256 11 543000000 Hz -1.3 dBmV 42.7 dB 590747077 25 115
13 Locked QAM256 12 549000000 Hz -1.0 dBmV 42.8 dB 590758810 31 105
14 Locked QAM256 13 555000000 Hz -1.3 dBmV 42.7 dB 590769337 31 106
15 Locked QAM256 14 561000000 Hz -1.5 dBmV 42.7 dB 590780981 34 106
16 Locked QAM256 15 567000000 Hz -1.6 dBmV 42.3 dB 590791799 26 110
17 Locked QAM256 16 573000000 Hz -1.6 dBmV 42.3 dB 590806387 29 110
18 Locked QAM256 17 579000000 Hz -1.6 dBmV 42.3 dB 590817146 26 114
19 Locked QAM256 18 585000000 Hz -1.6 dBmV 42.3 dB 590828067 25 100
20 Locked QAM256 19 591000000 Hz -1.9 dBmV 41.8 dB 590839424 28 104
21 Locked QAM256 20 597000000 Hz -2.0 dBmV 42.0 dB 590850729 27 94
22 Locked QAM256 21 603000000 Hz -1.6 dBmV 42.0 dB 590861755 22 104
23 Locked QAM256 22 609000000 Hz -1.9 dBmV 41.8 dB 590872907 26 97
24 Locked QAM256 23 615000000 Hz -2.7 dBmV 41.7 dB 590884422 27 99
25 Locked QAM256 24 621000000 Hz -2.3 dBmV 41.7 dB 590895820 21 105
26 Locked QAM256 25 627000000 Hz -2.2 dBmV 41.7 dB 590907058 31 106
27 Locked QAM256 26 633000000 Hz -2.3 dBmV 41.6 dB 590918054 26 85
28 Locked QAM256 27 639000000 Hz -3.1 dBmV 41.0 dB 590929738 24 92
29 Locked QAM256 28 645000000 Hz -3.1 dBmV 41.1 dB 590941234 19 102
30 Locked QAM256 30 657000000 Hz -3.0 dBmV 41.2 dB 590947002 24 87
31 Locked QAM256 31 663000000 Hz -3.4 dBmV 41.0 dB 590947986 19 90
32 Not Locked Unknown 0 0 Hz 0.0 dBmV 0.0 dB 0 0 0

<tabindex=-1>Upstream Bonded Channels</tabindex=-1>
Channel Lock Status Modulation Channel ID Frequency Power
1 Locked ATDMA 73 34900000 Hz 44.5 dBmV
2 Locked ATDMA 74 28500000 Hz 45.3 dBmV
3 Locked ATDMA 75 22100000 Hz 45.5 dBmV
4 Locked ATDMA 76 15700000 Hz 46.3 dBmV
5 Not Locked Unknown 0 0 Hz 0.0 dBmV
6 Not Locked Unknown 0 0 Hz 0.0 dBmV
7 Not Locked Unknown 0 0 Hz 0.0 dBmV
8 Not Locked Unknown 0 0 Hz 0.0 dBmV

<tabindex=-1>Downstream OFDM Channels</tabindex=-1>
Channel Lock Status Modulation / Profile ID Channel ID Frequency Power SNR / MER Active Subcarrier Number Range Unerrored Codewords Correctable Codewords Uncorrectable Codewords
1 Locked 0, 1, 255 33 722000000 Hz -6.7 dBmV 37.5 dB 1228 ~ 2867 1587293400 1553413500 0
2 Not Locked 0, 255 0 0 Hz -1.1 dBmV 0.0 dB 0 ~ 4095 0 0 0

<tabindex=-1>Upstream OFDMA Channels</tabindex=-1>
Channel Lock Status Modulation / Profile ID Channel ID Frequency Power
1 Not Locked Unknown 0 0 Hz 0 dBmV
2 Not Locked Unknown 0 0 Hz 0 dBmV
Expert

Re: Random internet drops

Stats look o/k. Please post the error / event log entries as well.



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Regular Visitor

Re: Random internet drops

I replaced all of the MAC addresses with zeros.

 

Time Priority Description
2019-06-27, 19:15:12 Notice (6) DS profile assignment change. DS Chan ID: 32; Previous Profile: ; New Profile: 1 .;CM-MAC=00:00:00:00:00:00;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
2019-06-27, 19:15:01 Notice (6) Honoring MDD; IP provisioning mode = IPv6
2019-06-27, 19:14:46 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=00:00:00:00:00:00;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
2019-06-27, 19:14:30 Critical (3) No Ranging Response received - T3 time-out;CM-MAC=00:00:00:00:00:00;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
2019-06-27, 19:14:29 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=00:00:00:00:00:00;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
2019-06-27, 19:12:54 Critical (3) No Ranging Response received - T3 time-out;CM-MAC=00:00:00:00:00:00;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
2019-06-27, 19:12:46 Notice (6) CM-STATUS message sent. Event Type Code: 7; Chan ID: 74 ; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=00:00:00:00:00:00;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
2019-06-27, 19:12:18 Critical (3) No Ranging Response received - T3 time-out;CM-MAC=00:00:00:00:00:00;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
2019-06-27, 19:11:45 Notice (6) CM-STATUS message sent. Event Type Code: 7; Chan ID: 74 ; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=00:00:00:00:00:00;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
2019-06-27, 19:11:22 Critical (3) No Ranging Response received - T3 time-out;CM-MAC=00:00:00:00:00:00;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
2019-06-27, 19:11:15 Notice (6) CM-STATUS message sent. Event Type Code: 7; Chan ID: 74 ; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=00:00:00:00:00:00;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
2019-06-27, 19:10:52 Critical (3) No Ranging Response received - T3 time-out;CM-MAC=00:00:00:00:00:00;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
2019-06-27, 19:10:46 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=00:00:00:00:00:00;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
2019-06-27, 19:10:46 Critical (3) No Ranging Response received - T3 time-out;CM-MAC=00:00:00:00:00:00;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
2019-06-27, 19:10:45 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=00:00:00:00:00:00;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
2019-06-27, 19:10:44 Critical (3) No Ranging Response received - T3 time-out;CM-MAC=00:00:00:00:00:00;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
2019-06-27, 19:10:44 Notice (6) CM-STATUS message sent. Event Type Code: 7; Chan ID: 74 ; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=00:00:00:00:00:00;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
2019-06-27, 19:10:44 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=00:00:00:00:00:00;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
2019-06-27, 19:10:42 Critical (3) 16 consecutive T3 timeouts while trying to range on upstream channel 2;CM-MAC=00:00:00:00:00:00;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
2019-06-27, 19:10:42 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=00:00:00:00:00:00;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
2019-06-27, 19:09:24 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=00:00:00:00:00:00;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
2019-06-27, 19:09:23 Warning (5) Dynamic Range Window violation
2019-06-27, 19:09:23 Warning (5) RNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW;CM-MAC=00:00:00:00:00:00;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
2019-06-27, 19:09:23 Warning (5) Dynamic Range Window violation
2019-06-27, 19:09:23 Warning (5) RNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW;CM-MAC=00:00:00:00:00:00;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
2019-06-27, 19:09:23 Warning (5) Dynamic Range Window violation
2019-06-27, 19:09:23 Warning (5) RNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW;CM-MAC=00:00:00:00:00:00;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
2019-06-27, 19:09:23 Warning (5) Dynamic Range Window violation
2019-06-27, 19:09:23 Warning (5) RNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW;CM-MAC=00:00:00:00:00:00;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
2019-06-27, 19:01:44 Warning (5) Dynamic Range Window violation
2019-06-27, 19:01:44 Warning (5) RNG-RSP CCAP Commanded Power Exceeds Value Corresponding to the Top of the DRW;CM-MAC=00:00:00:00:00:00;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
2019-06-27, 19:00:54 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=00:00:00:00:00:00;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
2019-06-27, 18:54:20 Warning (5) Dynamic Range Window violation
2019-06-27, 18:54:20 Warning (5) RNG-RSP CCAP Commanded Power Exceeds Value Corresponding to the Top of the DRW;CM-MAC=00:00:00:00:00:00;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
2019-06-27, 18:54:20 Warning (5) Dynamic Range Window violation
2019-06-27, 18:54:20 Warning (5) RNG-RSP CCAP Commanded Power Exceeds Value Corresponding to the Top of the DRW;CM-MAC=00:00:00:00:00:00;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
2019-06-27, 18:54:20 Warning (5) Dynamic Range Window violation
2019-06-27, 18:54:20 Warning (5) RNG-RSP CCAP Commanded Power Exceeds Value Corresponding to the Top of the DRW;CM-MAC=00:00:00:00:00:00;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
2019-06-27, 18:54:04 Warning (5) Dynamic Range Window violation
2019-06-27, 18:54:04 Warning (5) RNG-RSP CCAP Commanded Power Exceeds Value Corresponding to the Top of the DRW;CM-MAC=00:00:00:00:00:00;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;

Expert

Re: Random internet drops

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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Official Employee

Re: Random internet drops

marmitt, thank you for reaching out here! I definitely understand the importance of having a reliable connection, and I'm here to help. Let's take a look at this further together to see what may be causing these issues. To get started, please send me a PM with your first and last name. Thank you! 

To send me a Private Message, please click my name “ComcastAlly” and click “Send a message.”


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Regular Visitor

Re: Random internet drops

I've started the process with the Comcast Tech. Thanks a ton! I can't wait to have reliable internet again.

Regular Visitor

Re: Random internet drops

I am having very similar issues and can not figure out how to PM you for help. Any shot you can throw me a PM to see how this works. It’s my first time using the forum
Official Employee

Re: Random internet drops

marmitt, I'm so glad we were able to get a tech sent out to resolve this issue! As you said, there was static build-up in the box and the technician was able to replace the faulty components. Please let us know if we can help out with anything else! 


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