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Sam_Som
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Saturday, December 3rd, 2022 8:51 PM

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Netgear CM1000v2 - Issue With SYNC Timing and UCD Invalid

Hello all,


So I've tested this out and it seems to be the main issue. I've noticed when I am uploading a 600MB video to YouTube on my phone while I am on my home wifi, my modem seems to ALWAYS reboot, I've tested this numerous times and this seems to be the main issue. Here are the event logs below, I am lost.

Any help would be greatly appreciated! It seems that this has just started to happen a month ago and I guess I just never really looked into it. Firmware is up to date on the modem and the modem is probably about 1 year old.

2022-12-03, 20:42:42 Warning (5) MDD message timeout;CM-MAC=XX:XX:XX:XX:XX:XX;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
2022-12-03, 20:42:30 Notice (6) CM-STATUS message sent. Event Type Code: 4; Chan ID: 19 22; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=XX:XX:XX:XX:XX:XX;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
2022-12-03, 20:42:24 Warning (5) MDD message timeout;CM-MAC=XX:XX:XX:XX:XX:XX;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
2022-12-03, 20:42:15 Notice (6) CM-STATUS message sent. Event Type Code: 4; Chan ID: 19 22; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=XX:XX:XX:XX:XX:XX;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
2022-12-03, 20:42:15 Notice (6) CM-STATUS message sent. Event Type Code: 5; Chan ID: 19 22; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=XX:XX:XX:XX:XX:XX;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
2022-12-03, 20:42:12 Notice (6) CM-STATUS message sent. Event Type Code: 2; Chan ID: 24; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=XX:XX:XX:XX:XX:XX;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
2022-12-03, 20:42:07 Notice (6) CM-STATUS message sent. Event Type Code: 4; Chan ID: 19; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=XX:XX:XX:XX:XX:XX;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
2022-12-03, 20:42:07 Notice (6) CM-STATUS message sent. Event Type Code: 5; Chan ID: 19; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=XX:XX:XX:XX:XX:XX;CMTS-MAC=00:00:00:00:00:00CM-QOS=1.1;CM-VER=3.1;
2022-12-03, 20:41:56 Critical (3) UCD invalid or channel unusable;CM-MAC=XX:XX:XX:XX:XX:XX;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
2022-12-03, 20:41:55 Warning (5) RCS Partial Service;CM-MAC=XX:XX:XX:XX:XX:XX;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
2022-12-03, 20:41:49 Critical (3) UCD invalid or channel unusable;CM-MAC=XX:XX:XX:XX:XX:XX;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
2022-12-03, 20:41:49 Notice (6) DS profile assignment change. DS Chan ID: 32; Previous Profile: ; New Profile: 1 2 3.;CM-MAC=XX:XX:XX:XX:XX:XX;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
2022-12-03, 20:41:35 Notice (6) Honoring MDD; IP provisioning mode = IPv6
2022-12-03, 20:41:31 Critical (3) UCD invalid or channel unusable;CM-MAC=bc:XX:XX:XX:XX:XX:XX;CMTS-MAC=00:00:00:00:00:00;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=XX:XX:XX:XX:XX:XX;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;

Procedure Status Comment
Acquire Downstream Channel 615000000 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 (Partial Service)</tabindex=-1>
Channel Lock Status Modulation Channel ID Frequency Power SNR / MER Unerrored Codewords Correctable Codewords Uncorrectable Codewords
1 Locked QAM256 28 615000000 Hz -6.2 dBmV 42.8 dB 21885284 0 0
2 Locked QAM256 13 525000000 Hz -5.1 dBmV 39.0 dB 20994965 0 0
3 Locked QAM256 14 531000000 Hz -5.0 dBmV 39.9 dB 20980442 0 0
4 Locked QAM256 15 537000000 Hz -5.1 dBmV 41.1 dB 21000049 0 0
5 Locked QAM256 16 543000000 Hz -5.5 dBmV 42.9 dB 21004167 0 0
6 Locked QAM256 17 549000000 Hz -5.9 dBmV 39.3 dB 21007518 0 0
7 Locked QAM256 18 555000000 Hz -6.0 dBmV 40.5 dB 21011306 0 0
8 Locked QAM256 19 561000000 Hz -5.7 dBmV 27.1 dB 11412869 4795971 3032625
9 Locked QAM256 20 567000000 Hz -5.5 dBmV 32.2 dB 21018094 234 0
10 Locked QAM256 21 573000000 Hz -5.6 dBmV 43.1 dB 21022287 0 0
11 Locked QAM256 22 579000000 Hz -4.9 dBmV 28.5 dB 15665787 1503282 1396017
12 Not Locked Unknown 0 0 Hz 0.0 dBmV 0.0 dB 0 0 0
13 Not Locked Unknown 0 0 Hz 0.0 dBmV 0.0 dB 0 0 0
14 Locked QAM256 25 597000000 Hz -6.0 dBmV 31.8 dB 21024206 7545 35
15 Locked QAM256 26 603000000 Hz -5.7 dBmV 37.5 dB 21034652 0 0
16 Locked QAM256 27 609000000 Hz -5.5 dBmV 43.6 dB 21039376 0 0
17 Locked QAM256 29 621000000 Hz -6.0 dBmV 39.0 dB 21035553 6144 5
18 Locked QAM256 30 627000000 Hz -5.2 dBmV 39.3 dB 21043864 112 0
19 Locked QAM256 31 633000000 Hz -4.6 dBmV 34.2 dB 21047140 63 0
20 Locked QAM256 32 639000000 Hz -4.8 dBmV 38.4 dB 20970962 74231 5626
21 Locked QAM256 33 645000000 Hz -5.3 dBmV 43.5 dB 21052053 0 0
22 Locked QAM256 34 651000000 Hz -5.5 dBmV 43.0 dB 21058518 0 0
23 Locked QAM256 35 657000000 Hz -5.8 dBmV 43.2 dB 21063203 0 0
24 Locked QAM256 36 663000000 Hz -5.9 dBmV 43.3 dB 21067312 0 0
25 Locked QAM256 37 669000000 Hz -6.5 dBmV 42.9 dB 21076239 0 0
26 Locked QAM256 38 675000000 Hz -6.6 dBmV 42.3 dB 21080006 0 0
27 Locked QAM256 39 681000000 Hz -6.2 dBmV 42.9 dB 21083940 0 0
28 Locked QAM256 40 687000000 Hz -5.6 dBmV 43.3 dB 21092453 0 0
29 Locked QAM256 41 693000000 Hz -5.0 dBmV 43.8 dB 21096731 0 0
30 Locked QAM256 42 699000000 Hz -4.5 dBmV 44.1 dB 21100764 0 0
31 Locked QAM256 43 705000000 Hz -4.4 dBmV 44.1 dB 21120279 0 0
32 Locked QAM256 44 711000000 Hz -5.1 dBmV 43.7 dB 21109067 0 0
<tabindex=-1>Upstream Bonded Channels</tabindex=-1>
Channel Lock Status Modulation Channel ID Frequency Power
1 Locked ATDMA 1 16400000 Hz 55.0 dBmV
2 Locked ATDMA 2 22800000 Hz 56.8 dBmV
3 Locked ATDMA 3 29200000 Hz 56.3 dBmV
4 Locked ATDMA 4 35600000 Hz 55.0 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</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, 3 193 957000000 Hz -6.1 dBmV 40.5 dB 148 ~ 3947 2578276 1490678 0
2 Not Locked 0 0 0 Hz -6.5 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

Question

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Updated 

3 years ago

708

4

0

EG

Expert

 • 

111.3K Messages

3 years ago

The upstream power is too high / out of spec. The downstream power is on the low / weak side as well. And some of the SNR values are too low /out of spec. That can cause random disconnects, spontaneous re-booting of the modem, speed, packet loss, latency problems, and the un-bonding of channels.

In an 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 5-1000 MHz, bi-directional, and no gold colored garbage from Radio Shack, Home Depot, Target, etc. Splitters should be swapped with known to be good / new ones to test.

Also check the coax cable for any damage such as cuts, nicks, abrasions, kinks, sharp bends, etc.

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.


Good luck with it !

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0

XfinityDilary

Official Employee

 • 

2.3K Messages

3 years ago

Hey, @Sam_Som! Thanks for posting on our Community Forums and sharing the modem logs. We appreciate the opportunity to help. I see @EG offered some troubleshooting steps we can try. Did you have a chance to work on those? Has the issue improved? If not, we can help set up a tech visit to investigate further. 

0

Sam_Som

Visitor

 • 

3 Messages

3 years ago

So I've checked the wires and they are good, this is how my wiring is set up.

I've decided to change it out to the other splitter in the basement, although that solved the issue with the modem reboot, now I am getting issues where it's the same EXACT thing happen with no modem reboot.
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</tabindex=-1>
Procedure Status Comment
Acquire Downstream Channel 615000000 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 (Partial Service)</tabindex=-1>
Channel Lock Status Modulation Channel ID Frequency Power SNR / MER Unerrored Codewords Correctable Codewords Uncorrectable Codewords
1 Locked QAM256 28 615000000 Hz -4.5 dBmV 43.7 dB 16076129 5 0
2 Locked QAM256 13 525000000 Hz -3.7 dBmV 41.1 dB 15104262 10 0
3 Locked QAM256 14 531000000 Hz -3.5 dBmV 42.4 dB 15090838 3 0
4 Locked QAM256 15 537000000 Hz -3.5 dBmV 43.4 dB 15110284 4 0
5 Locked QAM256 16 543000000 Hz -4.1 dBmV 44.1 dB 15113788 0 0
6 Locked QAM256 17 549000000 Hz -4.4 dBmV 39.1 dB 15117784 11 0
7 Locked QAM256 18 555000000 Hz -4.5 dBmV 42.2 dB 15121341 1 0
8 Locked QAM256 19 561000000 Hz -4.1 dBmV 31.2 dB 15124738 1 0
9 Locked QAM256 20 567000000 Hz -3.9 dBmV 34.8 dB 15128339 11 0
10 Locked QAM256 21 573000000 Hz -4.0 dBmV 44.2 dB 15132483 5 0
11 Locked QAM256 22 579000000 Hz -3.3 dBmV 28.7 dB 13459474 632582 265635
12 Not Locked Unknown 0 0 Hz 0.0 dBmV 0.0 dB 0 0 0
13 Not Locked Unknown 0 0 Hz 0.0 dBmV 0.0 dB 0 0 0
14 Locked QAM256 25 597000000 Hz -4.1 dBmV 29.7 dB 15023170 111315 5847
15 Locked QAM256 26 603000000 Hz -3.8 dBmV 35.2 dB 15144030 6 0
16 Locked QAM256 27 609000000 Hz -3.8 dBmV 44.3 dB 15147919 4 0
17 Locked QAM256 29 621000000 Hz -4.2 dBmV 43.3 dB 15150093 3 0
18 Locked QAM256 30 627000000 Hz -3.4 dBmV 32.6 dB 15152448 36 0
19 Locked QAM256 31 633000000 Hz -3.0 dBmV 36.0 dB 15155891 1 0
20 Locked QAM256 32 639000000 Hz -3.2 dBmV 39.7 dB 15159666 210 0
21 Locked QAM256 33 645000000 Hz -3.7 dBmV 44.2 dB 15163509 3 0
22 Locked QAM256 34 651000000 Hz -4.0 dBmV 43.9 dB 15167431 3 0
23 Locked QAM256 35 657000000 Hz -4.2 dBmV 44.0 dB 15170646 4 0
24 Locked QAM256 36 663000000 Hz -4.3 dBmV 43.9 dB 15174688 5 0
25 Locked QAM256 37 669000000 Hz -4.9 dBmV 43.5 dB 15178987 3 0
26 Locked QAM256 38 675000000 Hz -4.9 dBmV 42.8 dB 15182356 10 0
27 Locked QAM256 39 681000000 Hz -4.6 dBmV 43.7 dB 15185685 2 0
28 Locked QAM256 40 687000000 Hz -3.9 dBmV 44.1 dB 15189583 2 0
29 Locked QAM256 41 693000000 Hz -3.3 dBmV 44.6 dB 15193775 1 0
30 Locked QAM256 42 699000000 Hz -3.0 dBmV 44.9 dB 15197396 1 0
31 Locked QAM256 43 705000000 Hz -2.8 dBmV 44.8 dB 15215986 1 0
32 Locked QAM256 44 711000000 Hz -3.5 dBmV 44.4 dB 15203339 1 0
<tabindex=-1>Upstream Bonded Channels</tabindex=-1>
Channel Lock Status Modulation Channel ID Frequency Power
1 Locked ATDMA 1 16400000 Hz 54.8 dBmV
2 Locked ATDMA 2 22800000 Hz 56.5 dBmV
3 Locked ATDMA 3 29200000 Hz 56.0 dBmV
4 Locked ATDMA 4 35600000 Hz 54.8 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, 3 193 957000000 Hz -4.2 dBmV 41.3 dB 148 ~ 3947 1617923 639651 0
2 Not Locked 0 0 0 Hz -5.4 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
Current System Time: Sat Dec 16 20:53:20 2022
System Up Time: 0:06:30

1

0

RB_MD

Contributor

 • 

21 Messages

@Sam_Som​ 

Given that your downstreams are on the low side and upstreams are way high, have you tried removing the splitter entirely and just swapping in a coupler there?  And as EG said, double/triple check all connections for loose connectors or shorts...

3 years ago

0

EG

Expert

 • 

111.3K Messages

3 years ago

It's still N/G. You may want to get a tech out to investigate as was stated. Bear in mind that if the premises facing techs can not find or fix a problem at your home, it is they who are responsible for escalating it to their line / network / maintenance dept. techs. The problem may lie beyond your home in the local neighborhood infrastructure somewhere but it is their S.O.P. to start at the home. And if the problem is found to be on their side of the demarcation point, there will not be any charge.


Good luck !

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