H

Monday, August 21st, 2023 11:54 PM

Closed

Intermittent Internet Access

It's been a very frustrating day being run around by Xfinity. I have been having intermittent connection issues for a few months now. Every time I've contacted support, they've reset the modem, and it's worked fine for a while until it eventually cuts out again. This morning I was in the middle of a work meeting when the internet cut out abruptly. My modem eventually comes back online, but the speeds are half of what they should be. I talked to an Xfinity representative who told me that there was no issues and that everything was working fine and has been for weeks. After we are done talking, I check the modem's logs and, lo and behold, it's reporting Critical errors. Not fine. I then try to get ahold of a different representative who essentially tells me the same thing, but that they will open a ticket about it and call me back. When I finally get a call back, they're stuttering and mumbling through their usual script before they suddenly stop talking all together. I did not get another call back.

I am using a Netgear CM1100 modem with a Netgear AX4300 router. See the modem logs below (I have redacted any MAC addresses). The Critical errors show up any time the modem is rebooted. Sometimes it is an intentional reboot, other times it's unintentional like this morning when my connection dropped.

<tabindex=-1>Startup Procedure</tabindex=-1>
Procedure Status Comment
Acquire Downstream Channel 531000000 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</tabindex=-1>
Channel Lock Status Modulation Channel ID Frequency Power SNR / MER Unerrored Codewords Correctable Codewords Uncorrectable Codewords
1 Locked QAM256 20 531000000 Hz 9.2 dBmV 44.7 dB 414704496 0 0
2 Locked QAM256 1 417000000 Hz 8.2 dBmV 44.5 dB 413825479 0 0
3 Locked QAM256 2 423000000 Hz 8.2 dBmV 44.4 dB 413829068 0 0
4 Locked QAM256 3 429000000 Hz 8.3 dBmV 44.5 dB 413817105 0 0
5 Locked QAM256 4 435000000 Hz 8.4 dBmV 44.6 dB 413819534 0 0
6 Locked QAM256 5 441000000 Hz 8.4 dBmV 44.5 dB 413838512 0 0
7 Locked QAM256 6 447000000 Hz 8.5 dBmV 44.5 dB 413842487 0 0
8 Locked QAM256 7 453000000 Hz 8.5 dBmV 44.6 dB 413847308 0 0
9 Locked QAM256 8 459000000 Hz 8.5 dBmV 44.6 dB 413850410 0 0
10 Locked QAM256 9 465000000 Hz 8.6 dBmV 44.6 dB 413854107 0 0
11 Locked QAM256 10 471000000 Hz 8.7 dBmV 44.6 dB 413857384 0 0
12 Locked QAM256 11 477000000 Hz 8.8 dBmV 44.7 dB 413862199 0 0
13 Locked QAM256 12 483000000 Hz 8.8 dBmV 44.6 dB 413864918 0 0
14 Locked QAM256 13 489000000 Hz 8.9 dBmV 44.7 dB 413868678 0 0
15 Locked QAM256 14 495000000 Hz 9.0 dBmV 44.7 dB 413873874 0 0
16 Locked QAM256 15 501000000 Hz 9.0 dBmV 44.7 dB 413876346 0 0
17 Locked QAM256 16 507000000 Hz 9.1 dBmV 44.7 dB 413881263 0 0
18 Locked QAM256 17 513000000 Hz 9.2 dBmV 44.7 dB 413885495 0 0
19 Locked QAM256 18 519000000 Hz 9.2 dBmV 44.8 dB 413888832 0 0
20 Locked QAM256 19 525000000 Hz 9.2 dBmV 44.8 dB 413892300 0 0
21 Locked QAM256 21 537000000 Hz 9.1 dBmV 44.6 dB 413896671 0 0
22 Locked QAM256 22 543000000 Hz 9.0 dBmV 44.5 dB 413899804 0 0
23 Locked QAM256 23 549000000 Hz 8.9 dBmV 44.3 dB 413903662 0 0
24 Locked QAM256 24 555000000 Hz 8.8 dBmV 44.5 dB 413907691 0 0
25 Locked QAM256 25 561000000 Hz 9.0 dBmV 44.4 dB 413910292 0 0
26 Locked QAM256 26 567000000 Hz 9.2 dBmV 44.6 dB 413915323 0 0
27 Locked QAM256 27 573000000 Hz 9.3 dBmV 44.7 dB 413918688 0 0
28 Locked QAM256 28 579000000 Hz 9.3 dBmV 44.5 dB 413922950 0 0
29 Locked QAM256 29 585000000 Hz 9.2 dBmV 44.6 dB 413926599 0 0
30 Locked QAM256 30 591000000 Hz 9.2 dBmV 44.5 dB 413929004 0 0
31 Locked QAM256 31 597000000 Hz 9.2 dBmV 44.5 dB 413946327 0 0
32 Locked QAM256 32 603000000 Hz 9.2 dBmV 44.4 dB 413950034 0 0

<tabindex=-1>Upstream Bonded Channels</tabindex=-1>
Channel Lock Status Modulation Channel ID Frequency Power
1 Locked ATDMA 1 16400000 Hz 39.8 dBmV
2 Locked ATDMA 2 22800000 Hz 39.8 dBmV
3 Locked ATDMA 3 29200000 Hz 39.8 dBmV
4 Locked ATDMA 4 35600000 Hz 39.8 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 12.6 dBmV 43.8 dB 148 ~ 3947 32844552 996820 0
2 Not Locked 0 0 0 Hz 7.0 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: Mon Aug 21 15:37:22 2023

System Up Time: 2:32:44

2023-08-21, 21:05:31

Critical (3)

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

2023-08-21, 21:05:31

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=XX:XX:XX:XX:XX:XX;CM-QOS=1.1;CM-VER=3.1;

2023-08-21, 21:05:17

Notice (6)

Honoring MDD; IP provisioning mode = IPv6

2023-08-21, 21:05:13

Critical (3)

UCD invalid or channel unusable;CM-MAC=XX:XX:XX:XX:XX:XX;CMTS-MAC=XX:XX:XX:XX:XX:XX;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;

2023-08-21, 20:39:30

Critical (3)

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

2023-08-21, 20:39:12

Critical (3)

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

2023-08-21, 19:24:19

Critical (3)

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

2023-08-21, 19:24:01

Critical (3)

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

2023-08-21, 19:21:19

Critical (3)

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

2023-08-21, 19:21:11

Critical (3)

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

2023-08-21, 19:21:07

Critical (3)

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

2023-08-21, 19:20:20

Critical (3)

SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=XX:XX:XX:XX:XX:XX;CMTS-MAC=XX:XX:XX:XX:XX:XX;CM-QOS=1.1;CM-VER=3.1;

2023-08-21, 19:20:16

Critical (3)

SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=XX:XX:XX:XX:XX:XX;CMTS-MAC=XX:XX:XX:XX:XX:XX;CM-QOS=1.1;CM-VER=3.1;

2023-08-21, 17:23:03

Critical (3)

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

2023-08-21, 17:22:46

Critical (3)

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

2023-08-21, 17:20:53

Critical (3)

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

2023-08-21, 17:20:36

Critical (3)

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

2023-07-11, 01:17:36

Critical (3)

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

2023-07-11, 01:17:20

Critical (3)

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

2023-07-11, 01:09:14

Critical (3)

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

2023-07-11, 01:08:56

Critical (3)

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

2023-07-11, 01:07:04

Critical (3)

Resetting the cable modem due to docsDevResetNow

2023-07-01, 09:49:31

Critical (3)

Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=XX:XX:XX:XX:XX:XX;CMTS-MAC=XX:XX:XX:XX:XX:XX;CM-QOS=1.1;CM-VER=3.1;

2023-06-16, 02:28:01

Critical (3)

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

2023-06-16, 02:27:42

Critical (3)

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

2023-06-13, 19:11:28

Critical (3)

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

2023-06-13, 19:11:10

Critical (3)

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

2023-06-05, 23:05:00

Critical (3)

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

2023-06-05, 23:04:42

Critical (3)

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

 

Expert

 • 

110.7K Messages

2 years ago

This may or may not be the root cause of the problem (YMMV) but it should be addressed regardless.


The downstream power is too high / out of spec (especially on the OFDM channel). It may be over-driving the front-end receiver circuit of the modem. That can cause random disconnects, spontaneous re-booting of the modem, speed, packet loss, latency problems, and the un-bonding of channels.


Is there a drop amplifier on the coax cable line leading to the modem ? If so, try removing / bypassing it and see. If not, you can try installing a -6 dB forward path-only attenuator pad such as this one on the coax port on the rear of the modem to knock that power level down and see;


https://www.amazon.com/FPA6-54-Forward-Attenuator-DOCSIS-Internet/dp/B08KTRC3XZ  


It won't affect the upstream power level which is within spec. Good luck !

Official Employee

 • 

2.2K Messages

2 years ago

Hello @himynameisben thanks for using our Forums as a tool to get in contact with our Xfinity Support Team. We are happy to see what is going on and causing these intermittent connection issues that are stopping you from having a good experience with or Xfinity internet service. As recommended by our expert above do you have any kind of amplifiers in your set-up that could be causing these issues? 

8 Messages

2 years ago

Hi! I live in an apartment building, so from at least the cable outlet to my modem, there are no amplifiers or splits. Beyond that, I have no way to verify.

I have gone ahead and installed the adapter as EG recommended. I have noticed that the Downstream power has decreased across the board by about 6 dBmV as expected. I installed that at about 8/25/23 - 21:15:00 modem time. Despite that, I am still getting the same or similar critical errors from the modem logs. I rebooted the modem a couple times to be sure. Please advise.

<tabindex=-1>Startup Procedure</tabindex=-1>
Procedure Status Comment
Acquire Downstream Channel 531000000 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</tabindex=-1>
Channel Lock Status Modulation Channel ID Frequency Power SNR / MER Unerrored Codewords Correctable Codewords Uncorrectable Codewords
1 Locked QAM256 20 531000000 Hz 2.7 dBmV 45.2 dB 31808679 0 0
2 Locked QAM256 1 417000000 Hz 2.0 dBmV 45.0 dB 30929839 0 0
3 Locked QAM256 2 423000000 Hz 2.0 dBmV 45.0 dB 30918499 0 0
4 Locked QAM256 3 429000000 Hz 2.1 dBmV 45.1 dB 30935160 0 0
5 Locked QAM256 4 435000000 Hz 2.2 dBmV 45.0 dB 30938899 0 0
6 Locked QAM256 5 441000000 Hz 2.2 dBmV 45.2 dB 30942513 0 0
7 Locked QAM256 6 447000000 Hz 2.2 dBmV 45.3 dB 30946124 0 0
8 Locked QAM256 7 453000000 Hz 2.3 dBmV 45.3 dB 30950094 0 0
9 Locked QAM256 8 459000000 Hz 2.3 dBmV 45.1 dB 30954301 0 0
10 Locked QAM256 9 465000000 Hz 2.4 dBmV 45.3 dB 30958116 0 0
11 Locked QAM256 10 471000000 Hz 2.4 dBmV 45.1 dB 30961921 0 0
12 Locked QAM256 11 477000000 Hz 2.5 dBmV 45.2 dB 30965500 0 0
13 Locked QAM256 12 483000000 Hz 2.5 dBmV 45.3 dB 30969435 0 0
14 Locked QAM256 13 489000000 Hz 2.6 dBmV 45.2 dB 30972957 0 0
15 Locked QAM256 14 495000000 Hz 2.6 dBmV 45.3 dB 30976710 0 0
16 Locked QAM256 15 501000000 Hz 2.7 dBmV 45.4 dB 30980548 0 0
17 Locked QAM256 16 507000000 Hz 2.8 dBmV 45.2 dB 30984336 0 0
18 Locked QAM256 17 513000000 Hz 2.9 dBmV 45.3 dB 30987886 0 0
19 Locked QAM256 18 519000000 Hz 2.8 dBmV 45.4 dB 30991547 0 0
20 Locked QAM256 19 525000000 Hz 2.8 dBmV 45.4 dB 30995434 0 0
21 Locked QAM256 21 537000000 Hz 2.7 dBmV 45.1 dB 31000069 0 0
22 Locked QAM256 22 543000000 Hz 2.6 dBmV 45.2 dB 31003625 0 0
23 Locked QAM256 23 549000000 Hz 2.5 dBmV 45.1 dB 31007342 0 0
24 Locked QAM256 24 555000000 Hz 2.5 dBmV 45.1 dB 31010763 0 0
25 Locked QAM256 25 561000000 Hz 2.7 dBmV 45.1 dB 31014967 0 0
26 Locked QAM256 26 567000000 Hz 2.8 dBmV 45.1 dB 31018481 0 0
27 Locked QAM256 27 573000000 Hz 2.8 dBmV 45.2 dB 31022195 0 0
28 Locked QAM256 28 579000000 Hz 2.8 dBmV 45.2 dB 31025959 0 0
29 Locked QAM256 29 585000000 Hz 2.8 dBmV 45.1 dB 31029590 0 0
30 Locked QAM256 30 591000000 Hz 2.8 dBmV 45.1 dB 31033898 0 0
31 Locked QAM256 31 597000000 Hz 3.0 dBmV 45.1 dB 31050616 0 0
32 Locked QAM256 32 603000000 Hz 3.1 dBmV 45.0 dB 31039655 0 0

<tabindex=-1>Upstream Bonded Channels</tabindex=-1>
Channel Lock Status Modulation Channel ID Frequency Power
1 Locked ATDMA 1 16400000 Hz 41.0 dBmV
2 Locked ATDMA 2 22800000 Hz 41.0 dBmV
3 Locked ATDMA 3 29200000 Hz 41.3 dBmV
4 Locked ATDMA 4 35600000 Hz 41.3 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 5.9 dBmV 44.0 dB 148 ~ 3947 1046384 22042 0
2 Not Locked 0 0 0 Hz 0.9 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: Fri Aug 25 13:42:25 2023
System Up Time: 0:12:17



Time

Priority

Description

2023-08-25, 21:31:01

Critical (3)

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

2023-08-25, 21:31:01

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=XX:XX:XX:XX:XX:XX;CM-QOS=1.1;CM-VER=3.1;

2023-08-25, 21:30:47

Notice (6)

Honoring MDD; IP provisioning mode = IPv6

2023-08-25, 21:30:42

Critical (3)

UCD invalid or channel unusable;CM-MAC=XX:XX:XX:XX:XX:XX;CMTS-MAC=XX:XX:XX:XX:XX:XX;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;

2023-08-25, 21:17:22

Critical (3)

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

2023-08-25, 21:17:03

Critical (3)

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

2023-08-23, 09:07:22

Critical (3)

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

2023-08-23, 09:07:07

Critical (3)

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

2023-08-23, 09:04:26

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;

2023-08-23, 09:04:21

Critical (3)

Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=XX:XX:XX:XX:XX:XX;CMTS-MAC=XX:XX:XX:XX:XX:XX;CM-QOS=1.1;CM-VER=3.1;

2023-08-23, 09:04:11

Critical (3)

SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=XX:XX:XX:XX:XX:XX;CMTS-MAC=XX:XX:XX:XX:XX:XX;CM-QOS=1.1;CM-VER=3.1;

2023-08-23, 09:04:10

Critical (3)

Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=XX:XX:XX:XX:XX:XX;CMTS-MAC=XX:XX:XX:XX:XX:XX;CM-QOS=1.1;CM-VER=3.1;

2023-08-23, 09:04:10

Critical (3)

SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=XX:XX:XX:XX:XX:XX;CMTS-MAC=XX:XX:XX:XX:XX:XX;CM-QOS=1.1;CM-VER=3.1;

2023-08-23, 09:04:09

Critical (3)

Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=XX:XX:XX:XX:XX:XX;CMTS-MAC=XX:XX:XX:XX:XX:XX;CM-QOS=1.1;CM-VER=3.1;

2023-08-23, 09:03:35

Critical (3)

SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=XX:XX:XX:XX:XX:XX;CMTS-MAC=XX:XX:XX:XX:XX:XX;CM-QOS=1.1;CM-VER=3.1;

2023-08-23, 09:03:29

Critical (3)

SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=XX:XX:XX:XX:XX:XX;CMTS-MAC=XX:XX:XX:XX:XX:XX;CM-QOS=1.1;CM-VER=3.1;

2023-08-23, 09:03:26

Critical (3)

SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=XX:XX:XX:XX:XX:XX;CMTS-MAC=XX:XX:XX:XX:XX:XX;CM-QOS=1.1;CM-VER=3.1;

2023-08-23, 09:00:56

Critical (3)

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

2023-08-23, 09:00:43

Critical (3)

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

2023-08-23, 08:59:03

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;

2023-08-23, 08:58:53

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;

2023-08-23, 08:58:43

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;

2023-08-23, 08:58:33

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;

2023-08-23, 08:58:23

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;

2023-08-23, 08:58:13

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;

2023-08-23, 08:58:03

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;

2023-08-23, 08:57:51

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;

2023-08-23, 08:57:15

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;

2023-08-23, 08:56:14

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;

2023-08-23, 08:55:27

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;

2023-08-23, 08:51:20

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;

2023-08-23, 08:47:10

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;

2023-08-23, 08:43:01

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;

2023-08-23, 08:38:54

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;

2023-08-23, 08:34:45

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;

2023-08-23, 08:30:35

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;

2023-08-23, 08:26:27

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;

 

8 Messages

2 years ago

Internet speeds are sitting at about 260 Mbps of the 400 I'm paying for.

Official Employee

 • 

3.1K Messages

Thank you so much for reaching back out and providing those details. Are you getting those speeds through a hardwired connection or through a WiFi connection? Also, do you have any devices hardwired that you can try running a speed test on to see what you are getting?

I am an Official Xfinity Employee.
Official Employees are from multiple teams within Xfinity: CARE, Product, Leadership.
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8 Messages

I'm still getting around the same speeds. I tested on several different devices.

Official Employee

 • 

1.7K Messages

@himynameisben are you able to confirm if you're getting the slow speed while connected directly to the modem, while using an Ethernet cable? Bypassing your router is always ideal when troubleshooting a speed issue.

 

In terms of an intermittent connection. Do you continue to lose connection or has that stopped? 

I am an Official Xfinity Employee.
Official Employees are from multiple teams within Xfinity: CARE, Product, Leadership.
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8 Messages

Confirmed that those speeds were when connected using Ethernet.

I haven't lost connection in the last couple days, no, but it previously was infrequent and randomly drops every week or so. The modem reboots, and it runs fine for a while until it inevitably happens again. Because of the drops, several of my devices do not always functioning properly. Last time this happened was in the middle of a work meeting. I would like to prevent that from happening again.

Official Employee

 • 

3.4K Messages

Thank you for confirming all of that information. Given the troubleshooting steps you've already taken I would like to get a look at the signals on our end, as well as check that ticket. Please send a DM to Xfinity Support with your full name and address to get started. 

To send a direct message:
Click "Sign In" if necessary
Click the "Direct Message" icon or  https://forums.xfinity.com/direct-messaging
Click the "New message" (pencil and paper) icon
The "To:" line prompts you to "Type the name of a person". Instead, type "Xfinity Support" there.
As you are typing a drop-down list appears. Select "Xfinity Support" from that list.
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Type your message in the text area near the bottom of the window
 Press Enter to send it

I am an Official Xfinity Employee.
Official Employees are from multiple teams within Xfinity: CARE, Product, Leadership.
We ask that you post publicly so people with similar questions may benefit from the conversation.
Was your question answered? Please, mark a reply as the Accepted Answer.tick

8 Messages

2 years ago

Just had a technician out to take a look. He replaced the coax cable from the modem to the wall. Not sure if he did anything else outside the unit or not. Our speeds rose up to the right amount, so he left. That only lasted about an hour or so until the speeds dropped back down to 200Mbps. I checked the modem logs again, and we're still getting those critical errors.

<tabindex=-1>Startup Procedure</tabindex=-1>
Procedure Status Comment
Acquire Downstream Channel 531000000 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</tabindex=-1>
Channel Lock Status Modulation Channel ID Frequency Power SNR / MER Unerrored Codewords Correctable Codewords Uncorrectable Codewords
1 Locked QAM256 20 531000000 Hz 6.0 dBmV 44.8 dB 516121241 0 0
2 Locked QAM256 1 417000000 Hz 5.2 dBmV 44.6 dB 515276133 0 0
3 Locked QAM256 2 423000000 Hz 5.2 dBmV 44.7 dB 515264679 0 0
4 Locked QAM256 3 429000000 Hz 5.2 dBmV 44.6 dB 515281099 0 0
5 Locked QAM256 4 435000000 Hz 5.3 dBmV 44.6 dB 515285053 0 0
6 Locked QAM256 5 441000000 Hz 5.2 dBmV 44.6 dB 515288368 0 0
7 Locked QAM256 6 447000000 Hz 5.3 dBmV 44.7 dB 515292076 0 0
8 Locked QAM256 7 453000000 Hz 5.4 dBmV 44.6 dB 515295697 0 0
9 Locked QAM256 8 459000000 Hz 5.4 dBmV 44.5 dB 515300351 0 0
10 Locked QAM256 9 465000000 Hz 5.5 dBmV 44.8 dB 515304247 0 0
11 Locked QAM256 10 471000000 Hz 5.6 dBmV 44.7 dB 515307943 0 0
12 Locked QAM256 11 477000000 Hz 5.7 dBmV 44.7 dB 515311818 0 0
13 Locked QAM256 12 483000000 Hz 5.7 dBmV 44.8 dB 515315419 0 0
14 Locked QAM256 13 489000000 Hz 5.9 dBmV 44.9 dB 515319155 0 0
15 Locked QAM256 14 495000000 Hz 5.9 dBmV 44.9 dB 515323210 0 0
16 Locked QAM256 15 501000000 Hz 6.0 dBmV 45.0 dB 515326452 0 0
17 Locked QAM256 16 507000000 Hz 6.1 dBmV 44.8 dB 515329606 0 0
18 Locked QAM256 17 513000000 Hz 6.1 dBmV 44.9 dB 515332952 0 0
19 Locked QAM256 18 519000000 Hz 6.1 dBmV 44.9 dB 515337625 0 0
20 Locked QAM256 19 525000000 Hz 6.1 dBmV 44.7 dB 515341669 0 0
21 Locked QAM256 21 537000000 Hz 6.0 dBmV 44.8 dB 515345259 0 0
22 Locked QAM256 22 543000000 Hz 5.9 dBmV 44.6 dB 515349259 0 0
23 Locked QAM256 23 549000000 Hz 5.8 dBmV 44.7 dB 515352903 0 0
24 Locked QAM256 24 555000000 Hz 5.8 dBmV 44.7 dB 515356622 0 0
25 Locked QAM256 25 561000000 Hz 5.9 dBmV 44.7 dB 515360385 0 0
26 Locked QAM256 26 567000000 Hz 6.0 dBmV 44.7 dB 515364476 0 0
27 Locked QAM256 27 573000000 Hz 6.1 dBmV 44.8 dB 515367344 0 0
28 Locked QAM256 28 579000000 Hz 6.2 dBmV 44.8 dB 515372171 0 0
29 Locked QAM256 29 585000000 Hz 6.2 dBmV 44.7 dB 515375706 0 0
30 Locked QAM256 30 591000000 Hz 6.2 dBmV 44.8 dB 515379567 0 0
31 Locked QAM256 31 597000000 Hz 6.3 dBmV 44.7 dB 515396128 0 0
32 Locked QAM256 32 603000000 Hz 6.3 dBmV 44.6 dB 515385467 0 0

<tabindex=-1>Upstream Bonded Channels</tabindex=-1>
Channel Lock Status Modulation Channel ID Frequency Power
1 Locked ATDMA 1 16400000 Hz 43.3 dBmV
2 Locked ATDMA 2 22800000 Hz 43.3 dBmV
3 Locked ATDMA 3 29200000 Hz 43.5 dBmV
4 Locked ATDMA 4 35600000 Hz 43.5 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 9.6 dBmV 44.0 dB 148 ~ 3947 35968028 1064697 0
2 Not Locked 0 0 0 Hz 3.7 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: Tue Aug 29 13:45:07 2023
System Up Time: 3:09:55

Time

Priority

Description

2023-08-29, 18:36:05

Critical (3)

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

2023-08-29, 18:36:05

Notice (6)

DS profile assignment change. DS Chan ID: 32; Previous Profile: ; New Profile: 1 2 3.;CM-MAC=00:00:00:00:00:00;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;

2023-08-29, 18:35:52

Notice (6)

Honoring MDD; IP provisioning mode = IPv6

2023-08-29, 18:35:48

Critical (3)

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

2023-08-29, 18:28:50

Critical (3)

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

2023-08-29, 18:28:32

Critical (3)

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

2023-08-29, 18:24:01

Critical (3)

Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=00:00:00:00:00:00;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;

2023-08-29, 18:23:56

Critical (3)

SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=00:00:00:00:00:00;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;

2023-08-29, 18:23:56

Critical (3)

Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=00:00:00:00:00:00;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;

2023-08-29, 18:23:56

Critical (3)

SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=00:00:00:00:00:00;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;

2023-08-29, 18:23:55

Critical (3)

Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=00:00:00:00:00:00;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;

2023-08-29, 18:23:20

Critical (3)

SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=00:00:00:00:00:00;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;

2023-08-29, 18:23:09

Critical (3)

SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=00:00:00:00:00:00;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;

2023-08-29, 18:23:06

Critical (3)

SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=00:00:00:00:00:00;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;

2023-08-28, 18:42:43

Critical (3)

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

2023-08-28, 18:42:24

Critical (3)

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

2023-08-25, 21:31:01

Critical (3)

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

2023-08-25, 21:30:42

Critical (3)

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

2023-08-25, 21:17:22

Critical (3)

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

2023-08-25, 21:17:03

Critical (3)

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

2023-08-23, 09:07:22

Critical (3)

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

2023-08-23, 09:07:07

Critical (3)

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

2023-08-23, 09:04:26

Critical (3)

SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=00:00:00:00:00:00;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;

2023-08-23, 09:04:21

Critical (3)

Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=00:00:00:00:00:00;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;

2023-08-23, 09:04:11

Critical (3)

SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=00:00:00:00:00:00;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;

2023-08-23, 09:04:10

Critical (3)

Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=00:00:00:00:00:00;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;

2023-08-23, 09:04:10

Critical (3)

SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=00:00:00:00:00:00;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;

2023-08-23, 09:04:09

Critical (3)

Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=00:00:00:00:00:00;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;

2023-08-23, 09:03:35

Critical (3)

SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=00:00:00:00:00:00;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;

2023-08-23, 09:03:29

Critical (3)

SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=00:00:00:00:00:00;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;

2023-08-23, 09:03:26

Critical (3)

SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=00:00:00:00:00:00;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;

2023-08-23, 09:00:56

Critical (3)

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

2023-08-23, 09:00:43

Critical (3)

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

2023-08-23, 08:59:03

Critical (3)

SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=00:00:00:00:00:00;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;

 

Official Employee

 • 

1.7K Messages

Hey there @himynameisben thanks so much for sharing these error logs and channel bonding information.  We do have certain information recorded here as well that can be used to help pinpoint the possible origin of these issues.  We're happy to continue working with you here as well as our Live chat.

I am an Official Xfinity Employee.
Official Employees are from multiple teams within Xfinity: CARE, Product, Leadership.
We ask that you post publicly so people with similar questions may benefit from the conversation.
Was your question answered? Please, mark a reply as the Accepted Answer.tick
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