Many critical T3 errors in cable modem log

I'm troubleshooting some connectivity issues, can anyone interpret this status log from my cable modem and let me know if there's anything I should be concerned about or look further into?

Last 6 characters of MAC addresses have been removed

Time Priority Description
Tue Mar 08 11:20:08 2022 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=28:80:88:xx:xx:xx;CMTS-MAC=00:01:5c:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
Tue Mar 08 11:05:57 2022 Notice (6) CM-STATUS message sent. Event Type Code: 8; Chan ID: 5; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=28:80:88:xx:xx:xx;CMTS-MAC=00:01:5c:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
Tue Mar 08 11:05:35 2022 Critical (3) 16 consecutive T3 timeouts while trying to range on upstream channel 1;CM-MAC=28:80:88:xx:xx:xx;CMTS-MAC=00:01:5c:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
Tue Mar 08 11:05:35 2022 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=28:80:88:xx:xx:xx;CMTS-MAC=00:01:5c:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
Tue Mar 08 11:05:35 2022 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=28:80:88:xx:xx:xx;CMTS-MAC=00:01:5c:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
Mon Mar 07 14:11:22 2022 Notice (6) CM-STATUS message sent. Event Type Code: 5; Chan ID: 48; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=28:80:88:xx:xx:xx;CMTS-MAC=00:01:5c:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
Mon Mar 07 14:11:09 2022 Notice (6) DS profile assignment change. DS Chan ID: 32; Previous Profile: ; New Profile: 1 2 3.;CM-MAC=28:80:88:xx:xx:xx;CMTS-MAC=00:01:5c:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
Mon Mar 07 14:11:08 2022 Notice (6) TLV-11 - unrecognized OID;CM-MAC=28:80:88:xx:xx:xx;CMTS-MAC=00:01:5c:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
Mon Mar 07 14:11:12 2022 Notice (6) Honoring MDD; IP provisioning mode = IPv6
Mon Mar 07 14:10:59 2022 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=28:80:88:xx:xx:xx;CMTS-MAC=00:01:5c:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
Mon Mar 07 14:10:51 2022 Critical (3) No Ranging Response received - T3 time-out;CM-MAC=28:80:88:xx:xx:xx;CMTS-MAC=00:01:5c:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
Mon Mar 07 14:10:39 2022 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=28:80:88:xx:xx:xx;CMTS-MAC=00:01:5c:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
Mon Mar 07 14:10:33 2022 Critical (3) No Ranging Response received - T3 time-out;CM-MAC=28:80:88:xx:xx:xx;CMTS-MAC=00:01:5c:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
Mon Mar 07 14:10:10 2022 Critical (3) 16 consecutive T3 timeouts while trying to range on upstream channel 3;CM-MAC=28:80:88:xx:xx:xx;CMTS-MAC=00:01:5c:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
Mon Mar 07 14:10:10 2022 Critical (3) Ranging Request Retries exhausted;CM-MAC=28:80:88:xx:xx:xx;CMTS-MAC=00:01:5c:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
Mon Mar 07 14:10:10 2022 Critical (3) No Ranging Response received - T3 time-out;CM-MAC=28:80:88:xx:xx:xx;CMTS-MAC=00:01:5c:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
Mon Mar 07 14:06:59 2022 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=28:80:88:xx:xx:xx;CMTS-MAC=00:01:5c:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
Mon Mar 07 14:06:56 2022 Critical (3) No Ranging Response received - T3 time-out;CM-MAC=28:80:88:xx:xx:xx;CMTS-MAC=00:01:5c:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
Mon Mar 07 14:06:56 2022 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=28:80:88:xx:xx:xx;CMTS-MAC=00:01:5c:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
Mon Mar 07 14:06:51 2022 Critical (3) No Ranging Response received - T3 time-out;CM-MAC=28:80:88:xx:xx:xx;CMTS-MAC=00:01:5c:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
Mon Mar 07 14:06:51 2022 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=28:80:88:xx:xx:xx;CMTS-MAC=00:01:5c:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
Mon Mar 07 14:06:49 2022 Critical (3) No Ranging Response received - T3 time-out;CM-MAC=28:80:88:xx:xx:xx;CMTS-MAC=00:01:5c:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
Mon Mar 07 14:06:48 2022 Critical (3) 16 consecutive T3 timeouts while trying to range on upstream channel 0;CM-MAC=28:80:88:xx:xx:xx;CMTS-MAC=00:01:5c:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
Mon Mar 07 14:06:48 2022 Critical (3) Ranging Request Retries exhausted;CM-MAC=28:80:88:xx:xx:xx;CMTS-MAC=00:01:5c:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
Mon Mar 07 14:06:48 2022 Critical (3) No Ranging Response received - T3 time-out;CM-MAC=28:80:88:xx:xx:xx;CMTS-MAC=00:01:5c:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
Mon Mar 07 14:06:48 2022 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=28:80:88:xx:xx:xx;CMTS-MAC=00:01:5c:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
Mon Mar 07 14:06:46 2022 Critical (3) No Ranging Response received - T3 time-out;CM-MAC=28:80:88:xx:xx:xx;CMTS-MAC=00:01:5c:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
Mon Mar 07 14:06:46 2022 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=28:80:88:xx:xx:xx;CMTS-MAC=00:01:5c:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
Mon Mar 07 14:06:29 2022 Critical (3) No Ranging Response received - T3 time-out;CM-MAC=28:80:88:xx:xx:xx;CMTS-MAC=00:01:5c:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
Mon Mar 07 14:06:15 2022 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=28:80:88:xx:xx:xx;CMTS-MAC=00:01:5c:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
Mon Mar 07 14:06:12 2022 Critical (3) No Ranging Response received - T3 time-out;CM-MAC=28:80:88:xx:xx:xx;CMTS-MAC=00:01:5c:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
Mon Mar 07 14:05:50 2022 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=28:80:88:xx:xx:xx;CMTS-MAC=00:01:5c:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
Mon Mar 07 14:05:48 2022 Critical (3) No Ranging Response received - T3 time-out;CM-MAC=28:80:88:xx:xx:xx;CMTS-MAC=00:01:5c:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
Mon Mar 07 14:05:27 2022 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=28:80:88:xx:xx:xx;CMTS-MAC=00:01:5c:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
Mon Mar 07 14:05:17 2022 Critical (3) No Ranging Response received - T3 time-out;CM-MAC=28:80:88:xx:xx:xx;CMTS-MAC=00:01:5c:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
Mon Mar 07 14:05:02 2022 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=28:80:88:xx:xx:xx;CMTS-MAC=00:01:5c:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
Mon Mar 07 14:04:54 2022 Critical (3) No Ranging Response received - T3 time-out;CM-MAC=28:80:88:xx:xx:xx;CMTS-MAC=00:01:5c:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
Mon Mar 07 14:04:44 2022 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=28:80:88:xx:xx:xx;CMTS-MAC=00:01:5c:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
Mon Mar 07 14:04:34 2022 Critical (3) No Ranging Response received - T3 time-out;CM-MAC=28:80:88:xx:xx:xx;CMTS-MAC=00:01:5c:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
Mon Mar 07 14:04:33 2022 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=28:80:88:xx:xx:xx;CMTS-MAC=00:01:5c:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;

Responses

Accepted Solution

EG

Expert

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110.1K Messages

3 years ago

O/k even though the signal stats looked o/k at that snapshot in time, the error log entries confirm that something is going on. Perhaps there is intermittent spurious noise ingress into the line(s) / an upstream channel / return path impairment somewhere.

There are other signal stat figures 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 that 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 poll for those upstream receive signal stats.

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

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5hl

Contributor

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40 Messages

@EG Another issue that I've just encountered is that out cable boxes keep losing connectivity. I power cycled the cable box and it went through bootup, tried to connect to services, failed and is now just a black screen.

3 years ago

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EG

Expert

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110.1K Messages

3 years ago

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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5hl

Contributor

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40 Messages

3 years ago

The log with the T3 errors were taken when I was experiencing 75% packet loss, so this signal log is from just a few minutes ago. I'll try to update it when I encounter the packet loss problem again

Startup Procedure

Procedure	Status	Comment
Acquire Downstream Channel	579000000 Hz	Locked
Connectivity State	OK	Operational
Boot State	OK	Operational
Security	Enabled	BPI+
IP Provisioning Mode	Honor MDD	honorMdd(4)

Downstream Bonded Channels

Channel	Lock Status	Modulation	Channel ID	Frequency	Power	SNR	Correctables	Uncorrectables
1	Locked	QAM256	32	579000000 Hz	0.5 dBmV	41.5 dB	41	56
2	Locked	QAM256	17	483000000 Hz	2 dBmV	42.8 dB	178	134
3	Locked	QAM256	18	489000000 Hz	1.8 dBmV	42.5 dB	115	205
4	Locked	QAM256	19	495000000 Hz	1.8 dBmV	42.5 dB	137	78
5	Locked	QAM256	20	507000000 Hz	1.7 dBmV	42.5 dB	121	145
6	Locked	QAM256	21	513000000 Hz	1.3 dBmV	42.4 dB	53	101
7	Locked	QAM256	22	519000000 Hz	0.9 dBmV	42.2 dB	131	145
8	Locked	QAM256	23	525000000 Hz	0.4 dBmV	42.1 dB	129	97
9	Locked	QAM256	24	531000000 Hz	0.3 dBmV	42.1 dB	29	65
10	Locked	QAM256	25	537000000 Hz	0.1 dBmV	41.9 dB	91	166
11	Locked	QAM256	26	543000000 Hz	-0.3 dBmV	41.7 dB	44	73
12	Locked	QAM256	27	549000000 Hz	-0.4 dBmV	41.7 dB	134	124
13	Locked	QAM256	28	555000000 Hz	-0.3 dBmV	41.6 dB	84	100
14	Locked	QAM256	29	561000000 Hz	-0.1 dBmV	41.7 dB	38	53
15	Locked	QAM256	30	567000000 Hz	-0.1 dBmV	41.6 dB	22	89
16	Locked	QAM256	31	573000000 Hz	0 dBmV	41.4 dB	55	86
17	Locked	QAM256	33	585000000 Hz	1.2 dBmV	41.9 dB	19	93
18	Locked	QAM256	34	591000000 Hz	1.3 dBmV	42 dB	42	81
19	Locked	QAM256	35	597000000 Hz	1.5 dBmV	42 dB	39	43
20	Locked	QAM256	36	603000000 Hz	1.6 dBmV	41.9 dB	16	86
21	Locked	QAM256	37	609000000 Hz	1.7 dBmV	42.1 dB	48	73
22	Locked	QAM256	38	615000000 Hz	1.8 dBmV	42.1 dB	21	75
23	Locked	QAM256	39	621000000 Hz	1.8 dBmV	42 dB	40	48
24	Locked	QAM256	40	627000000 Hz	1.8 dBmV	42 dB	19	74
25	Locked	QAM256	41	633000000 Hz	2 dBmV	42.1 dB	31	53
26	Locked	QAM256	42	639000000 Hz	2.3 dBmV	42.1 dB	27	44
27	Locked	QAM256	43	645000000 Hz	2.3 dBmV	42.2 dB	36	77
28	Locked	QAM256	44	651000000 Hz	2.1 dBmV	42.2 dB	43	60
29	Locked	QAM256	45	657000000 Hz	1.9 dBmV	42.1 dB	9	29
30	Locked	QAM256	46	663000000 Hz	2.2 dBmV	42.3 dB	6	47
31	Locked	QAM256	47	669000000 Hz	2.6 dBmV	42.4 dB	13	48
32	Not Locked	Unknown	0	0 Hz	0.0 dBmV	0.0 dB	0	0

Upstream Bonded Channels

Channel	Lock Status	US Channel Type	Channel ID	Symbol Rate	Frequency	Power
1	Locked	ATDMA	5	5120 Ksym/sec	16400000 Hz	40.3 dBmV
2	Locked	ATDMA	6	5120 Ksym/sec	22800000 Hz	39.8 dBmV
3	Locked	ATDMA	7	5120 Ksym/sec	29200000 Hz	40 dBmV
4	Locked	ATDMA	8	5120 Ksym/sec	35600000 Hz	40 dBmV
5	Not Locked	Unknown	0	0 Ksym/sec	0 Hz	0.0 dBmV
6	Not Locked	Unknown	0	0 Ksym/sec	0 Hz	0.0 dBmV
7	Not Locked	Unknown	0	0 Ksym/sec	0 Hz	0.0 dBmV
8	Not Locked	Unknown	0	0 Ksym/sec	0 Hz	0.0 dBmV

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	48	850000000 Hz	1.3 dBmV	41.3 dB	1108 ~ 2987	4209026753	3489682945	0
2	Not Locked	0	0	0 Hz	0 dBmV	0.0 dB	0 ~ 4095	0	0	0

Upstream OFDMA Channels

Channel	Lock Status	Modulation / Profile ID	Channel ID	Frequency	Power
1	Not Locked	0	0	0 Hz	0 dBmV
2	Not Locked	0	0	0 Hz	0 dBmV

Current System Time:Wed Mar 09 10:18:35 2022

System Up Time:2 days 22:15:16

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EG

Expert

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110.1K Messages

3 years ago

Please do. Most of those errors occurred within a very short time span. BTW, the signal stats were good at that snapshot in time.

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5hl

Contributor

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40 Messages

3 years ago

I just experienced an outage and when it occurred, I was not able to reach the web interface of my modem when internet drops so I can't pull the signal logs. My modem is a Netgear CM1150V and when it loses connectivity, the Upstream LED is off and my home phone has a fast busy or no tone at all. However, it does typically recover on it own sometimes within minutes, other times after an hour or more, without me rebooting/powercycling the modem.

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XfinityAmira

Official Employee

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4.1K Messages

Hello and thanks for taking the time to reach out to us on our Forums page in regard to the connection issues you have been experiencing. I know the importance of having a solid and steady connection, so I am sorry to hear this has not been the case for you. We would love to further look into/troubleshoot this on our end. To take a deeper look, please send us a Private Direct Message. Here are the detailed steps to direct message us:
• Click "Sign In" if necessary
• Click the "Direct Message icon” (upper right corner of this page)
• Click the "New message" (pencil and paper) icon
• Type "Xfinity Support" in the to line and select "Xfinity Support" from the drop-down list
• Type your message in the text area near the bottom of the window
• Press Enter to send your message

Thank you @EG for escalating, very much appreciated!

(Edited: Due to grammar)

(edited)

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3 years ago

5hl

Contributor

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40 Messages

3 years ago

@EG, thanks for escalating this to Comcast support. A technician came out last week and found that the terminals on the coax cable outside my home were corroded, replaced a filter and a splitter. My signal has been stable since.

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EG

Expert

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110.1K Messages

@5hl

Thanks for posting back. Hope things hold up for you ! Good luck ! Now closing your marked "solved" topic.

I am not a Comcast Employee.
I am a Customer Expert volunteering my time to help other customers here in the Forums.
We ask that you post publicly so people with similar questions may benefit from the conversation.

Was your question answered? Please mark an Accepted Answer! tick

3 years ago

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5hl

Many critical T3 errors in cable modem log

EG

5hl

EG

5hl

EG

5hl

XfinityAmira

5hl

EG

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