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Lotek216's avatar
Lotek216
New Contributor
5 years ago

Suspiciously High Data Usage, Netgear CM1000 Modem errors and Connection Issues...

I cancelled my contract with AT&T and switched over to Cox Gigablast last year for $119 a month. After the first few months of exceeding the 1TB data cap I went ahead and upgraded to the unlimited plan ($49.99/mo) to avoid all the overcharges.

I've been having a lot of connection problems and intermittent upload/download speeds the past several months. Went to the Cox website to see if there was a fix and noticed my data usage is still high (roughly 2TB a month). Considering I really only play Xbox One and use Chromecast to watch shows on Hulu/YouTube TV (720p/1080p only), I'm a little suspicious.

I checked the event log for my Netgear CM1000 modem and noticed a bunch of errors piled up such as:

  • RNG-RSP CCAP Commanded Power Exceeds Value Corresponding to the Top of the DRW
  • Dynamic Range Window violation
  • TLV-11 - unrecognized OID;

I'll add the event log and cable connection info below, if someone could take a look and help me make sense of all this I'd greatly appreciate it.

CM1000 Event Log:

Time Priority Description
2019-04-10, 20:14:50 Warning (5) Dynamic Range Window violation
2019-04-10, 20:14:50 Warning (5) RNG-RSP CCAP Commanded Power Exceeds Value Corresponding to the Top of the DRW;CM-MAC=cc:40:d0:25:6c:48;CMTS-MAC=70:6e:6d:2d:7e:ae;CM-QOS=1.1;CM-VER=3.1;
2019-04-10, 20:14:42 Notice (6) DS profile assignment change. DS Chan ID: 32; Previous Profile: ; New Profile: 1 2 3 .;CM-MAC=cc:40:d0:25:6c:48;CMTS-MAC=70:6e:6d:2d:7e:ae;CM-QOS=1.1;CM-VER=3.1;
2019-04-10, 20:14:32 Notice (6) TLV-11 - unrecognized OID;CM-MAC=cc:40:d0:25:6c:48;CMTS-MAC=70:6e:6d:2d:7e:ae;CM-QOS=1.1;CM-VER=3.1;
Time Not Established Warning (5) DHCP WARNING - Non-critical field invalid in response ;CM-MAC=cc:40:d0:25:6c:48;CMTS-MAC=70:6e:6d:2d:7e:ae;CM-QOS=1.1;CM-VER=3.1;
Time Not Established Notice (6) Honoring MDD; IP provisioning mode = IPv4
Time Not Established Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=cc:40:d0:25:6c:48;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
2019-03-18, 10:41:37 Critical (3) No Ranging Response received - T3 time-out;CM-MAC=cc:40:d0:25:6c:48;CMTS-MAC=70:6e:6d:2d:7e:ae;CM-QOS=1.1;CM-VER=3.1;
Time Not Established Critical (3) No Ranging Response received - T3 time-out;CM-MAC=cc:40:d0:25:6c:48;CMTS-MAC=70:6e:6d:2d:7e:ae;CM-QOS=1.1;CM-VER=3.1;
Time Not Established Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=cc:40:d0:25:6c:48;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
2019-02-24, 17:26:06 Critical (3) No Ranging Response received - T3 time-out;CM-MAC=cc:40:d0:25:6c:48;CMTS-MAC=70:6e:6d:2d:7e:ae;CM-QOS=1.1;CM-VER=3.1;
Time Not Established Critical (3) No Ranging Response received - T3 time-out;CM-MAC=cc:40:d0:25:6c:48;CMTS-MAC=70:6e:6d:2d:7e:ae;CM-QOS=1.1;CM-VER=3.1;
Time Not Established Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=cc:40:d0:25:6c:48;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
2019-02-24, 14:14:28 Critical (3) No Ranging Response received - T3 time-out;CM-MAC=cc:40:d0:25:6c:48;CMTS-MAC=70:6e:6d:2d:7e:ae;CM-QOS=1.1;CM-VER=3.1;
2019-02-24, 14:14:21 Critical (3) No Ranging Response received - T3 time-out;CM-MAC=cc:40:d0:25:6c:48;CMTS-MAC=70:6e:6d:2d:7e:ae;CM-QOS=1.1;CM-VER=3.1;
Time Not Established Critical (3) No Ranging Response received - T3 time-out;CM-MAC=cc:40:d0:25:6c:48;CMTS-MAC=70:6e:6d:2d:7e:ae;CM-QOS=1.1;CM-VER=3.1;
Time Not Established Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=cc:40:d0:25:6c:48;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
2019-02-24, 10:21:15 Critical (3) No Ranging Response received - T3 time-out;CM-MAC=cc:40:d0:25:6c:48;CMTS-MAC=70:6e:6d:2d:7e:ae;CM-QOS=1.1;CM-VER=3.1;
Time Not Established Critical (3) No Ranging Response received - T3 time-out;CM-MAC=cc:40:d0:25:6c:48;CMTS-MAC=70:6e:6d:2d:7e:ae;CM-QOS=1.1;CM-VER=3.1;
Time Not Established Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=cc:40:d0:25:6c:48;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
Time Not Established Critical (3) DHCP FAILED - Discover sent, no offer received;CM-MAC=cc:40:d0:25:6c:48;CMTS-MAC=70:6e:6d:2d:7e:ae;CM-QOS=1.1;CM-VER=3.1;
Time Not Established Critical (3) No Ranging Response received - T3 time-out;CM-MAC=cc:40:d0:25:6c:48;CMTS-MAC=70:6e:6d:2d:7e:ae;CM-QOS=1.1;CM-VER=3.1;
Time Not Established Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=cc:40:d0:25:6c:48;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
2019-01-24, 01:15:14 Critical (3) Resetting the cable modem due to docsDevResetNow
2019-01-18, 19:48:08 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=cc:40:d0:25:6c:48;CMTS-MAC=70:6e:6d:2d:7e:ae;CM-QOS=1.1;CM-VER=3.1;
2019-01-01, 00:56:51 Critical (3) No Ranging Response received - T3 time-out;CM-MAC=cc:40:d0:25:6c:48;CMTS-MAC=70:6e:6d:2d:7e:ae;CM-QOS=1.1;CM-VER=3.1;
Time Not Established Critical (3) No Ranging Response received - T3 time-out;CM-MAC=cc:40:d0:25:6c:48;CMTS-MAC=70:6e:6d:2d:7e:ae;CM-QOS=1.1;CM-VER=3.1;
Time Not Established Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=cc:40:d0:25:6c:48;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;

CM1000 Cable Connections Info:

Frequency start Value
This field below allows you to modify the frequency the cable modem start with its scan during initialization and registration. Enter the new start frequency and restart the cable modem for it to take effect.
Starting Frequency

<tabindex=-1>Startup Procedure
Procedure Status Comment
Acquire Downstream Channel 747000000 Hz Locked
Connectivity State OK Operational
Boot State OK Operational
Security Enable BPI+
IP Provisioning Mode Honor MDD IPv4 only

<tabindex=-1>Downstream Bonded Channels
Channel Lock Status Modulation Channel ID Frequency Power SNR / MER Unerrored Codewords Correctable Codewords Uncorrectable Codewords
1 Locked QAM256 12 747000000 Hz -0.3 dBmV 40.6 dB 2001198088 0 0
2 Locked QAM256 1 681000000 Hz -0.1 dBmV 40.9 dB 2000032230 0 0
3 Locked QAM256 2 687000000 Hz -0.4 dBmV 40.7 dB 2000043341 0 0
4 Locked QAM256 3 693000000 Hz -0.1 dBmV 40.3 dB 2000051596 0 0
5 Locked QAM256 4 699000000 Hz -0.5 dBmV 40.8 dB 2000060887 0 0
6 Locked QAM256 9 729000000 Hz -0.4 dBmV 40.5 dB 2000070749 0 0
7 Locked QAM256 10 735000000 Hz -0.2 dBmV 40.8 dB 2000079477 0 0
8 Locked QAM256 11 741000000 Hz -0.6 dBmV 40.6 dB 2000136913 0 0
9 Locked QAM256 17 777000000 Hz -0.4 dBmV 40.7 dB 2000154306 0 0
10 Locked QAM256 18 783000000 Hz -0.9 dBmV 40.7 dB 2000165882 0 0
11 Locked QAM256 19 789000000 Hz -0.9 dBmV 40.7 dB 2000174976 0 0
12 Locked QAM256 20 795000000 Hz -1.5 dBmV 40.5 dB 2000184328 0 0
13 Locked QAM256 21 801000000 Hz -1.7 dBmV 40.6 dB 2000192574 0 0
14 Locked QAM256 22 807000000 Hz -1.9 dBmV 40.5 dB 2000203480 0 0
15 Locked QAM256 25 825000000 Hz -2.3 dBmV 40.4 dB 2000193485 3654 12449
16 Locked QAM256 26 831000000 Hz -1.7 dBmV 40.4 dB 2000217773 1306 2609
17 Locked QAM256 27 837000000 Hz -1.7 dBmV 40.4 dB 2000211699 4799 15998
18 Locked QAM256 28 843000000 Hz -1.3 dBmV 40.5 dB 2000225199 4150 11140
19 Locked QAM256 29 849000000 Hz -1.0 dBmV 40.6 dB 2000250514 0 0
20 Locked QAM256 30 855000000 Hz -0.9 dBmV 40.7 dB 2000259503 0 0
21 Locked QAM256 33 357000000 Hz -3.0 dBmV 40.0 dB 2000269575 0 0
22 Locked QAM256 34 363000000 Hz -3.3 dBmV 40.3 dB 2000279148 0 0
23 Locked QAM256 35 369000000 Hz -3.2 dBmV 40.4 dB 2000287527 0 0
24 Locked QAM256 36 375000000 Hz -3.2 dBmV 40.3 dB 2000297314 0 0
25 Locked QAM256 37 381000000 Hz -2.8 dBmV 40.3 dB 2000306978 0 0
26 Locked QAM256 38 387000000 Hz -2.8 dBmV 39.8 dB 2000317294 0 0
27 Locked QAM256 41 405000000 Hz -2.3 dBmV 40.5 dB 2000325948 0 0
28 Locked QAM256 42 411000000 Hz -2.2 dBmV 40.8 dB 2000335715 0 0
29 Locked QAM256 43 417000000 Hz -2.2 dBmV 40.6 dB 2000352368 0 0
30 Locked QAM256 44 423000000 Hz -2.0 dBmV 40.7 dB 2000361024 0 0
31 Locked QAM256 45 429000000 Hz -2.0 dBmV 40.7 dB 2000368513 0 0
32 Locked QAM256 46 435000000 Hz -2.0 dBmV 40.6 dB 2000375095 0 0

<tabindex=-1>Upstream Bonded Channels
Channel Lock Status Modulation Channel ID Frequency Power
1 Locked ATDMA 1 17600000 Hz 38.0 dBmV
2 Locked ATDMA 2 24000000 Hz 39.3 dBmV
3 Locked ATDMA 3 30400000 Hz 40.8 dBmV
4 Locked ATDMA 4 36800000 Hz 41.0 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
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, 2, 3 159 300000000 Hz 1.0 dBmV 41.8 dB 1108 ~ 2987 1909972654 55424692 0
2 Not Locked 0 0 0 Hz -1.9 dBmV 0.0 dB 0 ~ 4095 0 0 0

<tabindex=-1>Upstream OFDMA Channels
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


My Equipment/Info:

  • Cox Gigablast 1000/35 + Unlimited data
  • Linksys WRT3200ACM
  • Netgear CM1000

1 Reply

  • @Lotek216. It looks like you may have some signal issues being reported by the modem. Please send us an email with your full address to cox.help@cox.com so we can look into this issue further. Thanks. -Allan Cox Support Forums Moderator.