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Visitor

 • 

8 Messages

Tuesday, July 8th, 2025 5:43 PM

Experiencing WAN outages multiple times per day since June 12

The outage period, as reported on my home network, is approximately 1min 30sec. 

Multiple times a day and throughout the date and night. 

Visitor

 • 

8 Messages

1 day ago

My modem reports UCD invalid or channel unusable errors multiple times a day. 

Expert

 • 

111.5K Messages

1 day ago

 Please post all of the error log entries in their entirety (copy and paste them, don't post a screenshot) but redact any CM MAC and the CMTS MAC addresses for your privacy. They are considered to be personal information. The posting of personally identifying information is a violation of their forum guidelines. The forum bot will not allow your post to be seen publicly.

Please also copy all of the text in its entirety of the *Downstream Power Levels*, the *SNR's* (Signal to Noise Ratios), and the *Upstream Power Level* numbers and paste them into your next post.

Visitor

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8 Messages

@EG​ 

Time 

 

Priority 

 

Description 

Time Not Established

 

Critical (3)

 

UCD invalid or channel unusable;CM-MAC=;CMTS-MAC=;CM-QOS=1.1;CM-VER=3.1;

18:00:39

Sat Jul 5 2025

 

Critical (3)

 

UCD invalid or channel unusable;CM-MAC=;CMTS-MAC=;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=;CMTS-MAC=;CM-QOS=1.1;CM-VER=3.1;

Time Not Established

 

Critical (3)

 

UCD invalid or channel unusable;CM-MAC=;CMTS-MAC=;CM-QOS=1.1;CM-VER=3.1;

21:45:40

Sat Jul 5 2025

 

Critical (3)

 

UCD invalid or channel unusable;CM-MAC=;CMTS-MAC=0;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=:CMTS-MAC=;CM-QOS=1.1;CM-VER=3.1;

Time Not Established

 

Critical (3)

 

UCD invalid or channel unusable;CM-MAC=;CMTS-MAC;CM-QOS=1.1;CM-VER=3.1;

04:45:38

Sun Jul 6 2025

 

Critical (3)

 

UCD invalid or channel unusable;CM-MAC=7;CMTS-MAC=;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=;CMTS-MAC=0;CM-QOS=1.1;CM-VER=3.1;

Time Not Established

 

Critical (3)

 

UCD invalid or channel unusable;CM-MAC=;CMTS-MAC=;CM-QOS=1.1;CM-VER=3.1;

11:30:35

Sun Jul 6 2025

 

Critical (3)

 

UCD invalid or channel unusable;CM-MAC=0;CMTS-MAC=;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=;CMTS-MAC=;CM-QOS=1.1;CM-VER=3.1;

Time Not Established

 

Critical (3)

 

UCD invalid or channel unusable;CM-MAC=;CMTS-MAC=;CM-QOS=1.1;CM-VER=3.1;

17:00:35

Sun Jul 6 2025

 

Critical (3)

 

UCD invalid or channel unusable;CM-MAC=;CMTS-MAC=;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=;CMTS-MAC=;CM-QOS=1.1;CM-VER=3.1;

Time Not Established

 

Critical (3)

 

UCD invalid or channel unusable;CM-MAC=7;CMTS-MAC=;CM-QOS=1.1;CM-VER=3.1;

15:45:41

Mon Jul 7 2025

 

Critical (3)

 

UCD invalid or channel unusable;CM-MAC=;CMTS-MAC=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=00:;CMTS-MAC=;CM-QOS=1.1;CM-VER=3.1;

Time Not Established

 

Critical (3)

 

UCD invalid or channel unusable;CM-MAC=;CMTS-MAC=;CM-QOS=1.1;CM-VER=3.1;

17:15:40

Mon Jul 7 2025

 

Critical (3)

 

UCD invalid or channel unusable;CM-MAC=7;CMTS-MAC=;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=0;CMTS-MAC=;CM-QOS=1.1;CM-VER=3.1;

Time Not Established

 

Critical (3)

 

UCD invalid or channel unusable;CM-MAC=;CMTS-MAC=;CM-QOS=1.1;CM-VER=3.1;

21:30:38

Mon Jul 7 2025

 

Critical (3)

 

UCD invalid or channel unusable;CM-MAC=;CMTS-MAC=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=CMTS-MAC=;CM-QOS=1.1;CM-VER=3.1;

Time Not Established

 

Critical (3)

 

UCD invalid or channel unusable;CM-MAC=;CMTS-MAC=;CM-QOS=1.1;CM-VER=3.1;

03:30:38

Tue Jul 8 2025

 

Critical (3)

 

UCD invalid or channel unusable;CM-MAC=;CMTS-MAC=;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=7;CMTS-MAC=0;CM-QOS=1.1;CM-VER=3.1;

Time Not Established

 

Critical (3)

 

UCD invalid or channel unusable;CM-MAC=;CMTS-MAC=;CM-QOS=1.1;CM-VER=3.1;

Time Not Established

 

Notice (6)

 

Honoring MDD; IP provisioning mode = IPv6

05:30:27

Tue Jul 8 2025

 

Notice (6)

 

DS profile assignment change. DS Chan ID: 32; Previous Profile: ; New Profile: 1 2 3.;CM-MAC=;CMTS-MAC=;CM-QOS=1.1;CM-VER=3.1;

05:30:36

Tue Jul 8 2025

 

Critical (3)

 

UCD invalid or channel unusable;CM-MAC=;CMTS-MAC=;CM-QOS=1.1;CM-VER=3.1;

05:34:23

Tue Jul 8 2025

 

Notice (6)

 

CM-STATUS message sent. Event Type Code: 24; Chan ID: 193; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 0.;CM-MAC=;CMTS-MAC=;CM-QOS=1.1;CM-VER=3.1;

Visitor

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8 Messages

@EG​ 

Number of Channels Connected



  
         Downstream 25
         Upstream 4

(edited)

Visitor

 • 

8 Messages

@EG​ 

Channel Lock Status Modulation Channel ID Freq. (MHz) Pwr (dBmV) SNR (dB) Corrected Uncorrected
   1 Locked QAM256 20 975.0 6.7 44.2 0 0
   2 Locked QAM256 1 387.0 6.5 45.2 0 0
   3 Locked QAM256 2 393.0 6.3 45.0 0 0
   4 Locked QAM256 3 399.0 6.1 44.9 0 0
   5 Locked QAM256 4 405.0 6.3 45.0 0 0
   6 Locked QAM256 5 411.0 6.4 44.9 0 0
   7 Locked QAM256 6 417.0 6.6 45.0 0 0
   8 Locked QAM256 7 423.0 6.6 45.1 0 0
   9 Locked QAM256 8 429.0 6.6 45.0 0 0
   10 Locked QAM256 9 435.0 6.5 45.0 0 0
   11 Locked QAM256 10 441.0 6.6 45.0 0 0
   12 Locked QAM256 11 447.0 6.7 45.0 0 0
   13 Locked QAM256 12 453.0 6.7 44.9 0 0
   14 Locked QAM256 13 459.0 6.8 45.0 0 0
   15 Locked QAM256 14 465.0 6.8 44.9 0 0
   16 Locked QAM256 15 471.0 6.9 45.0 0 0
   17 Locked QAM256 16 477.0 6.7 45.0 0 0
   18 Locked QAM256 17 957.0 6.2 44.1 0 0
   19 Locked QAM256 18 963.0 6.4 44.2 0 0
   20 Locked QAM256 19 969.0 6.7 44.2 0 0
   21 Locked QAM256 21 981.0 6.6 44.2 0 0
   22 Locked QAM256 22 987.0 6.6 44.0 0 0
   23 Locked QAM256 23 993.0 6.4 44.0 0 0
   24 Locked QAM256 24 999.0 6.3 43.8 0 0
   25 Locked OFDM PLC 193 774.0 6.7 44.2 794651 0

(edited)

Expert

 • 

111.5K Messages

1 day ago

Thank you. The error logs are ugly. The downstreams were in spec at that moment. Are the upstream channel values being shown ? If so, please post them as well.

Visitor

 • 

8 Messages

@EG​ 

Channel Lock Status Channel Type Channel ID Symb. Rate (Ksym/sec) Freq. (MHz) Pwr (dBmV)
   1 Locked SC-QAM 1 5120 16.4 34.0
   2 Locked SC-QAM 2 5120 22.8 34.5
   3 Locked SC-QAM 3 5120 29.2 35.0
   4 Locked SC-QAM 4 5120 35.6 35.5

Official Employee

 • 

2.3K Messages

 

Thanks for providing the logs, user_wtg1dt, and for working with @EG to get this resolved. We appreciate your insight, @EG. Let's take a further look here. Could you please send our team a Direct Message with your name and service address? Our team can help. 

 

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Expert

 • 

111.5K Messages

9 hours ago

The upstream power values are ok as well. So even though the signal status values looked OK at that snapshot in time, the error log entries confirm that something is going on. Perhaps there is noise ingress into the line(s) / an upstream channel / return path impairment somewhere.


There are other signal stat values 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 (The Digital Care Team) who are available to these boards. They will be able to poll the CMTS (Cable Modem Termination System) to check 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 check those upstream receive signal stats.

You should get a reply here in your topic. Good luck !

Visitor

 • 

8 Messages

@EG​ Much appreciate your assistance!

Expert

 • 

111.5K Messages

7 hours ago

@user_wtg1dt 

It's my pleasure ! 😊

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