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Connectivity Issues with Netgear CM1000

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Connectivity Issues with Netgear CM1000

I recently upgraded to gigabit speed last week, a tech came out and checked the outside and regrounded a wire.  My new Netgear CM1000 was arriving the next day so he had me call to have them provision which I did.  Setup took a couple of attempts but I was up and running.  My new equipment works, and speed tests will vary anywhere from 400-900 MBPS depending on when I check.  But my real issue is that there have been 3 occurences in the last week where the internet has cut out.  When I check the logs of the modem I do see that there are some Critical notices, I just am not so sure what they mean.  Cable Connection and Error Log pasted below.  Anything I can do to try to fix?

 

<tabindex=-1>Startup Procedure</tabindex=-1>
Procedure Status Comment
Acquire Downstream Channel 423000000 Hz Locked
Connectivity State OK Operational
Boot State OK Operational
Security Enable BPI+
IP Provisioning Mode Honor MDD IPv6 only

<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 38 423000000 Hz -10.7 dBmV 40.2 dB 1645357671 0 0
2 Locked QAM256 1 477000000 Hz -9.9 dBmV 41.0 dB 1644446242 0 0
3 Locked QAM256 2 483000000 Hz -9.5 dBmV 41.3 dB 1644449776 0 0
4 Locked QAM256 3 489000000 Hz -9.3 dBmV 41.5 dB 1644453480 1 0
5 Locked QAM256 4 495000000 Hz -8.8 dBmV 41.8 dB 1644457549 0 0
6 Locked QAM256 5 507000000 Hz -9.6 dBmV 41.4 dB 1644461072 0 0
7 Locked QAM256 6 513000000 Hz -9.4 dBmV 41.5 dB 1644466034 0 0
8 Locked QAM256 7 519000000 Hz -9.0 dBmV 41.6 dB 1644468570 0 0
9 Locked QAM256 8 525000000 Hz -8.9 dBmV 41.6 dB 1644474627 0 0
10 Locked QAM256 9 531000000 Hz -8.5 dBmV 42.0 dB 1644478350 1 0
11 Locked QAM256 10 537000000 Hz -8.7 dBmV 41.9 dB 1644483081 0 0
12 Locked QAM256 11 543000000 Hz -9.2 dBmV 41.7 dB 1644486106 0 0
13 Locked QAM256 12 549000000 Hz -9.8 dBmV 41.4 dB 1644489895 0 0
14 Locked QAM256 13 555000000 Hz -9.4 dBmV 41.6 dB 1644493409 1 0
15 Locked QAM256 14 561000000 Hz -9.9 dBmV 41.2 dB 1644497239 1 0
16 Locked QAM256 15 567000000 Hz -9.3 dBmV 41.4 dB 1644501553 0 0
17 Locked QAM256 16 573000000 Hz -9.8 dBmV 41.2 dB 1644510327 2 0
18 Locked QAM256 17 579000000 Hz -9.6 dBmV 41.2 dB 1644513351 1 0
19 Locked QAM256 18 585000000 Hz -9.8 dBmV 41.2 dB 1644517592 1 0
20 Locked QAM256 19 591000000 Hz -10.0 dBmV 41.0 dB 1644520897 1 0
21 Locked QAM256 20 597000000 Hz -9.9 dBmV 40.9 dB 1644524851 1 0
22 Locked QAM256 21 603000000 Hz -9.7 dBmV 40.9 dB 1644520865 2 0
23 Locked QAM256 22 609000000 Hz -9.8 dBmV 40.9 dB 1644523237 2 0
24 Locked QAM256 23 615000000 Hz -9.6 dBmV 41.0 dB 1644523533 0 0
25 Locked QAM256 32 453000000 Hz -9.9 dBmV 40.8 dB 1644504070 0 0
26 Locked QAM256 33 459000000 Hz -10.0 dBmV 40.8 dB 1644508243 1 0
27 Locked QAM256 34 465000000 Hz -9.6 dBmV 40.9 dB 1644511121 0 0
28 Locked QAM256 35 471000000 Hz -9.8 dBmV 41.0 dB 1644514515 0 0
29 Locked QAM256 39 429000000 Hz -10.2 dBmV 40.5 dB 1644518284 1 0
30 Locked QAM256 40 435000000 Hz -10.1 dBmV 40.6 dB 1644521031 0 0
31 Locked QAM256 41 441000000 Hz -9.9 dBmV 40.7 dB 1644522086 0 0
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 17 35800000 Hz 47.3 dBmV
2 Locked ATDMA 18 29400000 Hz 47.5 dBmV
3 Locked ATDMA 19 23000000 Hz 46.5 dBmV
4 Locked ATDMA 20 16600000 Hz 46.5 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, 2, 3 25 722000000 Hz -8.1 dBmV 39.8 dB 1228 ~ 2867 324939345 311185694 39
2 Not Locked 0 0 0 Hz -10.2 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
 

 

 

Error Log

Time Priority Description
2020-05-04, 12:23:57 Notice (6) CM-STATUS message sent. Event Type Code: 24; Chan ID: 25; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 3.;CM-MAC=38:94:ed:9d:9c:88;CMTS-MAC=00:01:5c:7f:9a:6c;CM-QOS=1.1;CM-VER=3.1;
2020-05-04, 12:23:30 Notice (6) CM-STATUS message sent. Event Type Code: 16; Chan ID: 25; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 3.;CM-MAC=38:94:ed:9d:9c:88;CMTS-MAC=00:01:5c:7f:9a:6c;CM-QOS=1.1;CM-VER=3.1;
2020-05-04, 12:22:39 Notice (6) DS profile assignment change. DS Chan ID: 32; Previous Profile: ; New Profile: 1 2 3.;CM-MAC=38:94:ed:9d:9c:88;CMTS-MAC=00:01:5c:7f:9a:6c;CM-QOS=1.1;CM-VER=3.1;
Time Not Established Notice (6) Honoring MDD; IP provisioning mode = IPv6
Time Not Established Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=38:94:ed:9d:9c:88;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
2020-05-04, 12:04:35 Critical (3) SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=38:94:ed:9d:9c:88;CMTS-MAC=00:01:5c:7f:9a:6c;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=38:94:ed:9d:9c:88;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
2020-05-04, 09:19:26 Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=38:94:ed:9d:9c:88;CMTS-MAC=00:01:5c:7f:9a:6c;CM-QOS=1.1;CM-VER=3.1;
2020-05-04, 08:35:50 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=38:94:ed:9d:9c:88;CMTS-MAC=00:01:5c:7f:9a:6c;CM-QOS=1.1;CM-VER=3.1;
2020-04-30, 19:15:27 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=38:94:ed:9d:9c:88;CMTS-MAC=00:01:5c:7f:9a:6c;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=38:94:ed:9d:9c:88;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
Time Not Established Critical (3) No Ranging Response received - T3 time-out;CM-MAC=38:94:ed:9d:9c:88;CMTS-MAC=00:01:5c:7f:9a:6c;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=38:94:ed:9d:9c:88;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
Time Not Established Critical (3) No Ranging Response received - T3 time-out;CM-MAC=38:94:ed:9d:9c:88;CMTS-MAC=00:01:5c:7f:9a:6c;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=38:94:ed:9d:9c:88;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
Time Not Established Critical (3) No Ranging Response received - T3 time-out;CM-MAC=38:94:ed:9d:9c:88;CMTS-MAC=00:01:5c:7f:9a:6c;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=38:94:ed:9d:9c:88;CMTS-MAC=00:00:00:00:00:00;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=38:94:ed:9d:9c:88;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
2020-01-13, 18:14:33 Critical (3) Telnet user logged out.

 

 

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Expert

Re: Connectivity Issues with Netgear CM1000

The downstream power is on the low side and it may be intermittently fluctuating even lower to out of spec levels. That can cause random disconnects, spontaneous re-booting of the modem, speed, packet loss, and latency problems.

In a self troubleshooting effort to try to obtain better connectivity / more wiggle room, check to see if there are there any excess/unneeded coax cable splitters in the line leading to the modem that can be eliminated/re-configured. Any splitters that remain should be high quality and cable rated for 5-1002 MHz, bi-directional, and no gold colored garbage types like GE, RadioShack, RCA, Philips, Leviton, Magnavox, and Rocketfish from big box stores like Home Depot, Lowes, Target, Wal-Mart etc. Splitters should be swapped with known to be good / new ones to test

If there aren't any unneeded splitters that can be eliminated and if your coax wiring setup can't be reconfigured so that there is a single two way splitter connected directly off of the drop from the street/pole with one port feeding the modem and the other port feeding the rest of the house/equipment with additional splits as needed, and you've checked all the wiring and fittings for integrity and tightness and refresh them by taking them apart then check for and clean off any corrosion / oxidation on the center wire and put them back together again, then perhaps it's best to book a tech visit to investigate and correct.



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