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user_62it7m
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Tuesday, October 22nd, 2024 2:09 AM

connection keeps dropping

My connection has been dropping intermittently for 2 weeks now.  I have had 2 technician out help troubleshoot. I have replaced my modem (S33), router, and patch cable.  The techs tested signals everywhere and even ran a new drop to my house and replace all coax ends. I have connected directly to my modem and to my router with ethernet and the signal drops that way as well. My modem log shows this several times if relevant. 

21/10/2024
18:26:57		 3 UCD invalid or channel unusable;CM-MAC=;CMTS-MAC=;CM-QOS=1.1;CM-VER=3.1;

I restart my modem and my Internet is great for about 20 minutes and then it drops and reconnects over and over. I am the only one in my neighborhood that has an issue but can't figure out what the issue is. The assistant will occasionally show that my modem is offline but most of the time it says I don't have a problem when I do.  Any suggestions?

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1 month ago

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EG

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1 month ago

What do the modem's signal status values look like ? 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.



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user_62it7m

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Channel ID Lock Status Modulation Frequency Power SNR/MER Corrected Uncorrectables
20 Locked QAM256 471000000 Hz 5 dBmV 43 dB 0 0
13 Locked QAM256 429000000 Hz 4 dBmV 43 dB 0 0
14 Locked QAM256 435000000 Hz 4 dBmV 43 dB 0 0
15 Locked QAM256 441000000 Hz 4 dBmV 43 dB 0 0
16 Locked QAM256 447000000 Hz 5 dBmV 43 dB 0 0
17 Locked QAM256 453000000 Hz 5 dBmV 43 dB 0 0
18 Locked QAM256 459000000 Hz 5 dBmV 43 dB 0 0
19 Locked QAM256 465000000 Hz 5 dBmV 43 dB 0 0
21 Locked QAM256 477000000 Hz 5 dBmV 43 dB 0 0
22 Locked QAM256 483000000 Hz 5 dBmV 43 dB 0 0
23 Locked QAM256 489000000 Hz 5 dBmV 43 dB 0 0
24 Locked QAM256 495000000 Hz 5 dBmV 43 dB 0 0
25 Locked QAM256 501000000 Hz 5 dBmV 43 dB 0 0
26 Locked QAM256 507000000 Hz 5 dBmV 43 dB 0 0
27 Locked QAM256 513000000 Hz 5 dBmV 43 dB 0 0
28 Locked QAM256 519000000 Hz 5 dBmV 43 dB 0 0
29 Locked QAM256 525000000 Hz 5 dBmV 43 dB 0 0
30 Locked QAM256 531000000 Hz 5 dBmV 43 dB 0 0
31 Locked QAM256 537000000 Hz 5 dBmV 43 dB 0 0
32 Locked QAM256 543000000 Hz 5 dBmV 43 dB 0 0
33 Locked QAM256 549000000 Hz 5 dBmV 43 dB 0 0
34 Locked QAM256 555000000 Hz 5 dBmV 43 dB 0 0
35 Locked QAM256 561000000 Hz 5 dBmV 43 dB 0 0
36 Locked QAM256 567000000 Hz 5 dBmV 43 dB 0 0
37 Locked QAM256 573000000 Hz 5 dBmV 43 dB 0 0
38 Locked QAM256 579000000 Hz 6 dBmV 43 dB 0 0
39 Locked QAM256 585000000 Hz 6 dBmV 43 dB 0 0
40 Locked QAM256 591000000 Hz 6 dBmV 43 dB 0 0
41 Locked QAM256 597000000 Hz 6 dBmV 43 dB 0 0
42 Locked QAM256 603000000 Hz 6 dBmV 43 dB 0 0
43 Locked QAM256 609000000 Hz 6 dBmV 43 dB 0 0
44 Locked QAM256 615000000 Hz 6 dBmV 43 dB 0 0
193 Locked OFDM PLC 690000000 Hz 7 dBmV 44 dB 592446 0
194 Locked OFDM PLC 957000000 Hz 11 dBmV 44 dB 111696 0


Upstream Bonded Channels
Channel ID Lock Status US Channel Type Frequency Width Power
1 Locked SC-QAM 16400000 Hz 6400000 47.3 dBmV
2 Locked SC-QAM 22800000 Hz 6400000 47.5 dBmV
3 Locked SC-QAM 29200000 Hz 6400000 47.5 dBmV
4 Locked SC-QAM 35600000 Hz 6400000 47.8 dBmV

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1 month ago

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EG

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1 month ago

The signal status values at that snapshot in time were OK / within specs. Please post the balance of the error log entries in their entirety but redact any and all CM and CMTS MAC addresses.

(edited)

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user_62it7m

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@EG​

31/12/1969
19:00:21		 3 CMSTATUS:US_Diplexer_Mode_Change_Ignored:TLV-21.1, 85MHz.
31/12/1969
19:00:23		 3 UCD invalid or channel unusable;CM-MAC=;CM-QOS=1.1;CM-VER=3.1;
31/12/1969
19:00:34		 3 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-84.2, 108MHz.
31/12/1969
19:00:34		 3 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-84.3, 1002MHz.
31/12/1969
19:00:34		 3 CMSTATUS:US_Diplexer_Mode_Change:TLV-84.1, 5-42MHz.
21/10/2024
13:53:27		 3 UCD invalid or channel unusable;CM-MAC=;CM-QOS=1.1;CM-VER=3.1;
21/10/2024
14:17:12		 3 Successful LAN WebGUI login from 174.179.133.120 on 24/10/21 at 2:17 PM.
21/10/2024
16:33:06		 3 Failed LAN WebGUI login attempt from 174.179.133.120 on 24/10/21 at 4:33 PM.
21/10/2024
16:33:15		 3 Successful LAN WebGUI login from 174.179.133.120 on 24/10/21 at 4:33 PM.
21/10/2024
17:22:29		 3 Successful LAN WebGUI login from 174.179.133.120 on 24/10/21 at 5:22 PM.
21/10/2024
17:53:00		 3 Successful LAN WebGUI login from 174.179.133.120 on 24/10/21 at 5:53 PM.
31/12/1969
19:00:16		 3 CMSTATUS:US_Diplexer_Mode_Change:Init, 5-42MHz.
31/12/1969
19:00:19		 3 SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC;CM-QOS=1.1;CM-VER=3.1;
31/12/1969
19:00:20		 3 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-21.2, 258MHz.
31/12/1969
19:00:20		 3 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-21.3, 1002MHz.
31/12/1969
19:00:20		 3 CMSTATUS:US_Diplexer_Mode_Change_Ignored:TLV-21.1, 85MHz.
31/12/1969
19:00:22		 3 UCD invalid or channel unusable;CM-MAC=;CM-QOS=1.1;CM-VER=3.1;
31/12/1969
19:00:35		 3 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-84.2, 108MHz.
31/12/1969
19:00:35		 3 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-84.3, 1002MHz.
31/12/1969
19:00:35		 3 CMSTATUS:US_Diplexer_Mode_Change:TLV-84.1, 5-42MHz.
21/10/2024
18:19:43		 3 UCD invalid or channel unusable;CM-MAC=0;CM-QOS=1.1;CM-VER=3.1;
21/10/2024
18:19:43		 3 Successful LAN WebGUI login from 192.168.100.10 on 24/10/21 at 6:19 PM.
21/10/2024
18:19:45		 3 UCD invalid or channel unusable;CM-MAC=0;CM-QOS=1.1;CM-VER=3.1;
31/12/1969
19:00:16		 3 CMSTATUS:US_Diplexer_Mode_Change:Init, 5-42MHz.
31/12/1969
19:00:20		 3 SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC;CM-QOS=1.1;CM-VER=3.1;
31/12/1969
19:00:21		 3 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-21.2, 258MHz.
31/12/1969
19:00:21		 3 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-21.3, 1002MHz.
31/12/1969
19:00:21		 3 CMSTATUS:US_Diplexer_Mode_Change_Ignored:TLV-21.1, 85MHz.
31/12/1969
19:00:23		 3 UCD invalid or channel unusable;CM-MAC=;CM-QOS=1.1;CM-VER=3.1;
31/12/1969
19:00:34		 3 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-84.2, 108MHz.
31/12/1969
19:00:34		 3 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-84.3, 1002MHz.
31/12/1969
19:00:34		 3 CMSTATUS:US_Diplexer_Mode_Change:TLV-84.1, 5-42MHz.
21/10/2024
18:26:57		 3 UCD invalid or channel unusable;CM-MAC=;CM-QOS=1.1;CM-VER=3.1;
21/10/2024
20:06:12		 3 Successful LAN WebGUI login from 174.179.133.120 on 24/10/21 at 8:06 PM.
21/10/2024
20:49:21		 3 Successful LAN WebGUI login from 174.179.133.120 on 24/10/21 at 8:49 PM.
21/10/2024
21:01:16		 3 Failed LAN WebGUI login attempt from 174.179.133.120 on 24/10/21 at 9:01 PM.
21/10/2024
21:01:22		 3 Successful LAN WebGUI login from 174.179.133.120 on 24/10/21 at 9:01 PM.
31/12/1969
19:00:16		 3 CMSTATUS:US_Diplexer_Mode_Change:Init, 5-42MHz.
31/12/1969
19:00:19		 3 SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC;CM-QOS=1.1;CM-VER=3.1;
31/12/1969
19:00:20		 3 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-21.2, 258MHz.
31/12/1969
19:00:20		 3 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-21.3, 1002MHz.
31/12/1969
19:00:20		 3 CMSTATUS:US_Diplexer_Mode_Change_Ignored:TLV-21.1, 85MHz.
31/12/1969
19:00:22		 3 UCD invalid or channel unusable;CM-MAC;CM-QOS=1.1;CM-VER=3.1;
31/12/1969
19:00:34		 3 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-84.2, 108MHz.
31/12/1969
19:00:34		 3 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-84.3, 1002MHz.
31/12/1969
19:00:34		 3 CMSTATUS:US_Diplexer_Mode_Change:TLV-84.1, 5-42MHz.
22/10/2024
14:56:24		 3 UCD invalid or channel unusable;CM-MAC=0;CM-QOS=1.1;CM-VER=3.1;
22/10/2024
15:00:22		 3 Successful LAN WebGUI login from 174.179.133.120 on 24/10/22 at 3:00 PM.
22/10/2024
16:24:32		 3 SYNC Timing Synchronization failure - Failed to receive MAC SYNC frame within time-out period;CM-MAC=;CM-QOS=1.1;CM-VER=3.1;
22/10/2024
16:24:36		 3 SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=;CM-QOS=1.1;CM-VER=3.1;
22/10/2024
16:25:23		 3 SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=;CM-QOS=1.1;CM-VER=3.1;
22/10/2024
16:25:23		 3 Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=;CM-QOS=1.1;CM-VER=3.1;
22/10/2024
16:25:31		 3 SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=;CM-QOS=1.1;CM-VER=3.1;
22/10/2024
16:25:31		 3 Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=;CM-QOS=1.1;CM-VER=3.1;
22/10/2024
16:29:55		 3 SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=;CM-QOS=1.1;CM-VER=3.1;
22/10/2024
16:31:58		 3 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-21.2, 258MHz.
22/10/2024
16:31:58		 3 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-21.3, 1002MHz.
22/10/2024
16:31:58		 3 CMSTATUS:US_Diplexer_Mode_Change_Ignored:TLV-21.1, 85MHz.
22/10/2024
16:32:00		 3 UCD invalid or channel unusable;CM-MACCM-QOS=1.1;CM-VER=3.1;
22/10/2024
16:32:11		 3 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-84.2, 108MHz.
22/10/2024
16:32:11		 3 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-84.3, 1002MHz.
22/10/2024
16:32:11		 3 CMSTATUS:US_Diplexer_Mode_Change:TLV-84.1, 5-42MHz.
22/10/2024
16:32:22		 3 UCD invalid or channel unusable;CM-MAC=;CM-QOS=1.1;CM-VER=3.1;
31/12/1969
19:00:16		 3 CMSTATUS:US_Diplexer_Mode_Change:Init, 5-42MHz.
31/12/1969
19:00:19		 3 SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=;CM-QOS=1.1;CM-VER=3.1;
31/12/1969
19:00:22		 3 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-21.2, 258MHz.
31/12/1969
19:00:22		 3 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-21.3, 1002MHz.
31/12/1969
19:00:22		 3 CMSTATUS:US_Diplexer_Mode_Change_Ignored:TLV-21.1, 85MHz.
31/12/1969
19:00:24		 3 UCD invalid or channel unusable;CM-MAC=d\;CM-QOS=1.1;CM-VER=3.1;
31/12/1969
19:00:36		 3 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-84.2, 108MHz.
31/12/1969
19:00:36		 3 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-84.3, 1002MHz.
31/12/1969
19:00:36		 3 CMSTATUS:US_Diplexer_Mode_Change:TLV-84.1, 5-42MHz.
22/10/2024
16:34:09		 3 UCD invalid or channel unusable;CM-MAC;CM-QOS=1.1;CM-VER=3.1;
22/10/2024
16:55:41		 3 Successful LAN WebGUI login from 174.179.133.120 on 24/10/22 at 4:55 PM.
31/12/1969
19:00:16		 3 CMSTATUS:US_Diplexer_Mode_Change:Init, 5-42MHz.
31/12/1969
19:00:19		 3 SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC;CM-QOS=1.1;CM-VER=3.1;
31/12/1969
19:00:20		 3 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-21.2, 258MHz.
31/12/1969
19:00:20		 3 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-21.3, 1002MHz.
31/12/1969
19:00:20		 3 CMSTATUS:US_Diplexer_Mode_Change_Ignored:TLV-21.1, 85MHz.
31/12/1969
19:00:22		 3 UCD invalid or channel unusable;;CM-QOS=1.1;CM-VER=3.1;
31/12/1969
19:00:34		 3 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-84.2, 108MHz.
31/12/1969
19:00:34		 3 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-84.3, 1002MHz.
31/12/1969
19:00:35		 3 CMSTATUS:US_Diplexer_Mode_Change:TLV-84.1, 5-42MHz.
23/10/2024
14:25:47		 3 UCD invalid or channel unusable;CM-QOS=1.1;CM-VER=3.1;
31/12/1969
19:00:16		 3 CMSTATUS:US_Diplexer_Mode_Change:Init, 5-42MHz.
31/12/1969
19:00:19		 3 SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-QOS=1.1;CM-VER=3.1;
31/12/1969
19:00:21		 3 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-21.2, 258MHz.
31/12/1969
19:00:21		 3 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-21.3, 1002MHz.
31/12/1969
19:00:21		 3 CMSTATUS:US_Diplexer_Mode_Change_Ignored:TLV-21.1, 85MHz.
31/12/1969
19:00:23		 3 UCD invalid or channel unusable;CM-MAC=d4:6c:6d:2b:55:09;CMTS-MAC=00:90:f0:6e:00:00;CM-QOS=1.1;CM-VER=3.1;
31/12/1969
19:00:27		 6 Honoring MDD; IP provisioning mode = IPv6
31/12/1969
19:00:35		 3 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-84.2, 108MHz.
31/12/1969
19:00:35		 3 CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-84.3, 1002MHz.
31/12/1969
19:00:35		 3 CMSTATUS:US_Diplexer_Mode_Change:TLV-84.1, 5-42MHz.
23/10/2024
15:04:16		 6 DS profile assignment change. DS Chan ID: 32; Previous Profile: ; New Profile: 1 2 3.;;CM-QOS=1.1;CM-VER=3.1;
23/10/2024
15:04:17		 6 DS profile assignment change. DS Chan ID: 33; Previous Profile: ; New Profile: 1 2 3.;;CM-QOS=1.1;CM-VER=3.1;
23/10/2024
15:04:25		 3 UCD invalid or channel unusable;CM-QOS=1.1;CM-VER=3.1;
23/10/2024
15:19:25		 3 Failed LAN WebGUI login attempt from 174.179.133.120 on 24/10/23 at 3:19 PM.
23/10/2024
15:19:30		 3 Successful LAN WebGUI login from 174.179.133.120 on 24/10/23 at 3:19 PM.
23/10/2024
15:36:08		 3 Successful LAN WebGUI login from 174.179.133.120 on 24/10/23 at 3:36 PM.

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1 month ago

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EG

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107.1K Messages

1 month ago

Thank you ! OK 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 !

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user_62it7m

5 Messages

Thanks for the help. 

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1 month ago

XfinityMartyR

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1.5K Messages

1 month ago

 

Thank you @EG for your insights! user_62it7m We would be more than happy to take a look at everything on our end. Please send us a direct message. 
 
To send a "Direct Message" message:
• Click "Sign In" if necessary
• Click the "Direct Message" icon
• Click the "New message" (pencil and paper) icon
• Type "Xfinity Support" in the "To:" line and select "Xfinity Support" from the drop-down list which appears. The "Xfinity Support" graphic replaces the "To:" line
• Type your message in the text area near the bottom of the window
• Press Enter to send it

 

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EG

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107.1K Messages

1 month ago

@user_62it7m  @XfinityMartyR  It's my pleasure !

(edited)

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