Intermittent Internet drops - 16 consecutive T3 timeouts while trying to range on upstream channel 2

I have been having really unreliable internet since moving into this house. I see the orange service line is above ground and a thicker service line is above ground and cut, so not sure that there is a history here. I have replaced my modem and router, but still have the same issue. The lights on the modem stay lit and blue, so I assumed it was not the modem or service, but I finally got to look at the modem log and despite it having a blue globe, I actually found critical errors in the log. This is a new modem, Motorola MB8600 DOCSIS 3.1 and actually, the third modem I have tried. So, if one upstream channel is lost, does that cause a service outage for me or is it just slower? The connection/channel information is when everything started to work again. I'll try to grab that when it isn't working next time. But is this log entry a clue to my problems?

16 consecutive T3 timeouts while trying to range on upstream channel 2

Logs:

08:31:13 Sun Oct 10 2021	Critical (3)	Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"]xx:xx:xx;CMTS-MAC=[Edited: "Personal Information"]:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
08:31:33 Sun Oct 10 2021	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"]:xx:xx:xx;CMTS-MAC=[Edited: "Personal Information"]:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
08:31:49 Sun Oct 10 2021	Critical (3)	Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"]:xx:xx:xx;CMTS-MAC=[Edited: "Personal Information"]:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
08:32:35 Sun Oct 10 2021	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"]:xx:xx:xx;CMTS-MAC=[Edited: "Personal Information"]:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
08:33:06 Sun Oct 10 2021	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"]:xx:xx:xx;CMTS-MAC=[Edited: "Personal Information"]:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
08:33:24 Sun Oct 10 2021	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"]:xx:xx:xx;CMTS-MAC=[Edited: "Personal Information"]:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
08:33:43 Sun Oct 10 2021	Critical (3)	Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"]:xx:xx:xx;CMTS-MAC=[Edited: "Personal Information"]:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
08:33:59 Sun Oct 10 2021	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"]:xx:xx:xx;CMTS-MAC=[Edited: "Personal Information"]:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
08:34:16 Sun Oct 10 2021	Critical (3)	Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"]:xx:xx:xx;CMTS-MAC=[Edited: "Personal Information"]:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
08:34:35 Sun Oct 10 2021	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"]:xx:xx:xx;CMTS-MAC=[Edited: "Personal Information"]:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
08:34:45 Sun Oct 10 2021	Critical (3)	Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"]:xx:xx:xx;CMTS-MAC=[Edited: "Personal Information"]:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
08:35:27 Sun Oct 10 2021	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"]:xx:xx:xx;CMTS-MAC=[Edited: "Personal Information"]:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
08:35:37 Sun Oct 10 2021	Critical (3)	Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"]:xx:xx:xx;CMTS-MAC=[Edited: "Personal Information"]:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
08:36:08 Sun Oct 10 2021	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"]:xx:xx:xx;CMTS-MAC=[Edited: "Personal Information"]:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
08:36:49 Sun Oct 10 2021	Critical (3)	Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"]:xx:xx:xx;CMTS-MAC=[Edited: "Personal Information"]:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
08:36:53 Sun Oct 10 2021	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"]:xx:xx:xx;CMTS-MAC=[Edited: "Personal Information"]:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
08:36:53 Sun Oct 10 2021	Critical (3)	Ranging Request Retries exhausted;CM-MAC=[Edited: "Personal Information"]:xx:xx:xx;CMTS-MAC=[Edited: "Personal Information"]:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
08:36:53 Sun Oct 10 2021	Critical (3)	16 consecutive T3 timeouts while trying to range on upstream channel 2;CM-MAC=[Edited: "Personal Information"]:xx:xx:xx;CMTS-MAC=[Edited: "Personal Information"]:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
08:36:57 Sun Oct 10 2021	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"]:xx:xx:xx;CMTS-MAC=[Edited: "Personal Information"]:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
08:37:22 Sun Oct 10 2021	Critical (3)	Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"]:xx:xx:xx;CMTS-MAC=[Edited: "Personal Information"]xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
08:37:46 Sun Oct 10 2021	Critical (3)	Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"]:xx:xx:xx;CMTS-MAC=[Edited: "Personal Information"]:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
08:38:10 Sun Oct 10 2021	Critical (3)	Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"]:xx:xx:xx;CMTS-MAC=[Edited: "Personal Information"]:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
08:38:41 Sun Oct 10 2021	Critical (3)	Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"]:xx:xx:xx;CMTS-MAC=[Edited: "Personal Information"]:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
08:46:13 Sun Oct 10 2021	Critical (3)	Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"]:xx:xx:xx;CMTS-MAC=[Edited: "Personal Information"]:xx:xx:xx;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=[Edited: "Personal Information"]:xx:xx:xx;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=[Edited: "Personal Information"]:xx:xx:xx;CMTS-MAC=[Edited: "Personal Information"]:xx:xx:xx;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=[Edited: "Personal Information"]:xx:xx:xx;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=[Edited: "Personal Information"]:xx:xx:xx;CMTS-MAC=[Edited: "Personal Information"]:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Notice (6)	Honoring MDD; IP provisioning mode = IPv6
08:07:13 Mon Oct 11 2021	Notice (6)	DS profile assignment change. DS Chan ID: 32; Previous Profile: ; New Profile: 1 2 3.;CM-MAC=[Edited: "Personal Information"]:xx:xx:xx;CMTS-MAC=[Edited: "Personal Information"]:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
08:24:21 Mon Oct 11 2021	Warning (5)	MDD message timeout;CM-MAC=[Edited: "Personal Information"]:xx:xx:xx;CMTS-MAC=[Edited: "Personal Information"]:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
08:24:23 Mon Oct 11 2021	Notice (6)	CM-STATUS message sent. Event Type Code: 4; Chan ID: 10 11 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 37; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=[Edited: "Personal Information"]:xx:xx:xx;CMTS-MAC=[Edited: "Personal Information"]:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;

Startup Step	Status	Comment
Acquire Downstream Channel	507000000 Hz	Locked
Upstream Connection	OK	Operational
Boot State	OK	Operational
Configuration File	OK
Security	Enabled	BPI+

Downstream Bonded Channels

Channel	Lock Status	Modulation	Channel ID	Freq. (MHz)	Pwr (dBmV)	SNR (dB)	Corrected	Uncorrected
1	Locked	QAM256	5	507.0	7.4	40.6	0	0
2	Locked	QAM256	2	483.0	7.9	40.7	0	0
3	Locked	QAM256	3	489.0	7.7	40.6	0	0
4	Locked	QAM256	4	495.0	7.5	39.8	0	0
5	Locked	QAM256	6	513.0	7.1	40.5	0	0
6	Locked	QAM256	7	519.0	6.9	40.3	0	0
7	Locked	QAM256	8	525.0	6.6	40.4	0	0
8	Locked	QAM256	9	531.0	6.7	40.4	0	0
9	Locked	QAM256	10	537.0	6.3	40.2	0	0
10	Locked	QAM256	11	543.0	6.3	40.1	0	0
11	Locked	QAM256	12	549.0	6.0	40.0	0	0
12	Locked	QAM256	13	555.0	6.1	39.9	0	0
13	Locked	QAM256	14	561.0	6.1	39.6	0	0
14	Locked	QAM256	15	567.0	6.0	39.8	0	0
15	Locked	QAM256	16	573.0	6.2	39.7	0	0
16	Locked	QAM256	17	579.0	6.1	39.8	0	0
17	Locked	QAM256	18	585.0	6.4	39.9	0	0
18	Locked	QAM256	19	591.0	6.7	39.8	0	0
19	Locked	QAM256	20	597.0	6.9	39.8	0	0
20	Locked	QAM256	21	603.0	6.5	39.6	0	0
21	Locked	QAM256	22	609.0	6.1	39.4	0	0
22	Locked	QAM256	23	615.0	5.9	39.0	0	0
23	Locked	QAM256	24	621.0	6.3	39.2	0	0
24	Locked	QAM256	25	627.0	6.7	39.2	0	0
25	Locked	QAM256	26	633.0	7.2	39.2	0	0
26	Locked	QAM256	27	639.0	7.5	38.9	0	0
27	Locked	QAM256	28	645.0	7.8	39.4	0	0
28	Locked	QAM256	29	651.0	7.8	39.2	0	0
29	Locked	QAM256	30	657.0	8.0	39.1	0	0
30	Locked	QAM256	31	663.0	8.1	39.0	0	0
31	Locked	QAM256	32	669.0	8.2	39.0	0	0
32	Locked	OFDM PLC	37	690.0	8.9	37.8	72073439	0

Upstream Bonded Channels

Channel	Lock Status	Channel Type	Channel ID	Symb. Rate (Ksym/sec)	Freq. (MHz)	Pwr (dBmV)
1	Locked	SC-QAM	1	5120	35.6	36.5
2	Locked	SC-QAM	2	5120	29.2	36.5
3	Locked	SC-QAM	3	5120	22.8	35.8
4	Locked	SC-QAM	4	5120	16.4	35.8
5	Locked	SC-QAM	9	1280	39.6	36.0

Responses

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Selected Oldest First

EG

Expert

•

112.2K Messages

4 years ago

@Valkyrie-MT

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 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 can check the CMTS (Cable Modem Termination System) 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 !

XfinityThomasC

Official Employee

•

2.7K Messages

4 years ago

Hello and thank you @Valkyrie-MT! I really appreciate you being a member of the Comcast Family! I'm sorry to hear you're having these issues since moving into your new home. Can you direct message us your name and address, please? Make sure you are signed in with your Xfinity credentials.

In the top right corner, you'll see a little chat icon near the bell icon. Click the direct message icon
Click the "New message" (pencil and paper) icon
In the 'To' line, type "Xfinity Support" there. A drop-down list appears. Select "Xfinity Support" from that list (an "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. An official employee, such as myself or whoever is first available, will respond. Thanks!

user_b4f173

Visitor

•

1 Message

4 years ago

I'm having the exact same error messages with extremely frequent outages. Can't resolve the outage until I disconnect/reconnect the COAX cable and reboot my modem. This is the 2nd modem I've purchased to resolve the issue and it is still ongoing. How can I resolve this?

(edited)

EG

Expert

•

112.2K Messages

4 years ago

@user_b4f173

Please create a new topic of your own here on this board detailing your issue. Thanks.

Your Home Network

Valkyrie-MT

Intermittent Internet drops - 16 consecutive T3 timeouts while trying to range on upstream channel 2

EG

XfinityThomasC

user_b4f173

EG

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