2 Messages
Internet connection frequently drops
Been having this problem starting about a month ago. I have a tech visit scheduled a week from now, but am posting here for additional feedback.
Observed behavior:
- Internet will stop working on all devices on my network, a couple of times times per hour.
- The lights on the modem (my own CM1000) are not flashing in the normal way, signifying some issue with the internet connection
- A few minutes later the modem lights return to normal and the internet reconnects.
Info from my modem's status pages:
Startup Procedure
|
Procedure |
Status |
Comment |
|
Acquire Downstream Channel |
525000000 Hz |
Locked |
|
Connectivity State |
OK |
Operational |
|
Boot State |
OK |
Operational |
|
Security |
Enable |
BPI+ |
|
IP Provisioning Mode |
Honor MDD |
IPv6 only |
Downstream Bonded Channels
|
Channel |
Lock Status |
Modulation |
Channel ID |
Frequency |
Power |
SNR / MER |
Unerrored Codewords |
Correctable Codewords |
Uncorrectable Codewords |
|
1 |
Locked |
QAM256 |
21 |
525000000 Hz |
0.6 dBmV |
40.9 dB |
7136218 |
0 |
0 |
|
2 |
Locked |
QAM256 |
1 |
399000000 Hz |
0.0 dBmV |
40.5 dB |
5947157 |
0 |
0 |
|
3 |
Locked |
QAM256 |
2 |
405000000 Hz |
0.1 dBmV |
40.5 dB |
5950705 |
0 |
0 |
|
4 |
Locked |
QAM256 |
3 |
411000000 Hz |
0.1 dBmV |
40.4 dB |
5939932 |
0 |
0 |
|
5 |
Locked |
QAM256 |
4 |
417000000 Hz |
0.1 dBmV |
40.6 dB |
5957380 |
0 |
0 |
|
6 |
Locked |
QAM256 |
5 |
423000000 Hz |
0.3 dBmV |
40.7 dB |
5961442 |
0 |
0 |
|
7 |
Locked |
QAM256 |
6 |
429000000 Hz |
0.4 dBmV |
40.7 dB |
5964966 |
0 |
0 |
|
8 |
Locked |
QAM256 |
7 |
435000000 Hz |
0.4 dBmV |
40.7 dB |
5968521 |
0 |
0 |
|
9 |
Locked |
QAM256 |
8 |
441000000 Hz |
0.3 dBmV |
40.7 dB |
5972262 |
0 |
0 |
|
10 |
Locked |
QAM256 |
9 |
447000000 Hz |
0.5 dBmV |
40.9 dB |
5975991 |
0 |
0 |
|
11 |
Locked |
QAM256 |
10 |
453000000 Hz |
0.6 dBmV |
40.9 dB |
5979703 |
0 |
0 |
|
12 |
Locked |
QAM256 |
11 |
459000000 Hz |
0.6 dBmV |
40.9 dB |
5983367 |
0 |
0 |
|
13 |
Locked |
QAM256 |
12 |
465000000 Hz |
0.6 dBmV |
40.9 dB |
5987261 |
0 |
0 |
|
14 |
Locked |
QAM256 |
13 |
471000000 Hz |
0.6 dBmV |
40.9 dB |
5990932 |
0 |
0 |
|
15 |
Locked |
QAM256 |
14 |
477000000 Hz |
0.6 dBmV |
40.9 dB |
5994650 |
0 |
0 |
|
16 |
Locked |
QAM256 |
15 |
483000000 Hz |
0.6 dBmV |
40.9 dB |
5998469 |
0 |
0 |
|
17 |
Locked |
QAM256 |
16 |
489000000 Hz |
0.6 dBmV |
40.8 dB |
6001846 |
0 |
0 |
|
18 |
Locked |
QAM256 |
17 |
495000000 Hz |
0.5 dBmV |
40.8 dB |
6005850 |
0 |
0 |
|
19 |
Locked |
QAM256 |
18 |
507000000 Hz |
0.6 dBmV |
40.6 dB |
6009744 |
0 |
0 |
|
20 |
Locked |
QAM256 |
19 |
513000000 Hz |
0.7 dBmV |
41.0 dB |
6013354 |
0 |
0 |
|
21 |
Locked |
QAM256 |
20 |
519000000 Hz |
0.7 dBmV |
41.0 dB |
6016834 |
0 |
0 |
|
22 |
Locked |
QAM256 |
22 |
531000000 Hz |
0.6 dBmV |
40.8 dB |
6020507 |
0 |
0 |
|
23 |
Locked |
QAM256 |
23 |
543000000 Hz |
0.9 dBmV |
40.4 dB |
6024429 |
0 |
0 |
|
24 |
Locked |
QAM256 |
24 |
549000000 Hz |
0.8 dBmV |
41.0 dB |
6028195 |
0 |
0 |
|
25 |
Locked |
QAM256 |
25 |
555000000 Hz |
0.9 dBmV |
41.0 dB |
6031724 |
0 |
0 |
|
26 |
Locked |
QAM256 |
26 |
561000000 Hz |
0.9 dBmV |
41.0 dB |
6035617 |
0 |
0 |
|
27 |
Locked |
QAM256 |
27 |
567000000 Hz |
1.0 dBmV |
41.1 dB |
6039208 |
0 |
0 |
|
28 |
Locked |
QAM256 |
28 |
573000000 Hz |
1.0 dBmV |
41.0 dB |
6043095 |
0 |
0 |
|
29 |
Locked |
QAM256 |
29 |
579000000 Hz |
1.1 dBmV |
41.0 dB |
6046578 |
0 |
0 |
|
30 |
Locked |
QAM256 |
30 |
585000000 Hz |
1.2 dBmV |
41.1 dB |
6050132 |
0 |
0 |
|
31 |
Locked |
QAM256 |
31 |
591000000 Hz |
1.4 dBmV |
40.9 dB |
6066736 |
0 |
0 |
|
32 |
Locked |
QAM256 |
32 |
597000000 Hz |
1.4 dBmV |
41.1 dB |
6052548 |
0 |
0 |
Upstream bonded channels
|
Channel |
Lock Status |
Modulation |
Channel ID |
Frequency |
Power |
|
1 |
Locked |
ATDMA |
9 |
10400000 Hz |
49.8 dBmV |
|
2 |
Locked |
ATDMA |
10 |
16400000 Hz |
49.8 dBmV |
|
3 |
Locked |
ATDMA |
11 |
22800000 Hz |
49.8 dBmV |
|
4 |
Locked |
ATDMA |
12 |
29200000 Hz |
49.8 dBmV |
|
5 |
Locked |
ATDMA |
13 |
35600000 Hz |
49.3 dBmV |
|
6 |
Locked |
ATDMA |
14 |
40400000 Hz |
49.3 dBmV |
|
7 |
Not Locked |
Unknown |
0 |
0 Hz |
0.0 dBmV |
|
8 |
Not Locked |
Unknown |
0 |
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 |
159 |
722000000 Hz |
2.4 dBmV |
40.0 dB |
946 ~ 3149 |
5265110 |
1019272 |
0 |
|
2 |
Not Locked |
0 |
0 |
0 Hz |
0.5 dBmV |
0.0 dB |
0 ~ 4095 |
0 |
0 |
0 |
Upstream OFDM channels
|
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 |
Cable modem information
|
Hardware Version |
2.02 |
|
Firmware Version |
V7.01.01 |
|
Cable Modem Serial Number |
4L058BWE04AFE |
|
CM certificate |
Installed |
|
CM MAC |
[Edited: “Personal Information”] |
Event log
|
Time |
Priority |
Description |
|
2024-10-18, 14:53:08 |
Warning (5) |
REG-RSP-MP Mismatch Between Calculated Value for P1.6hi Compared to CCAP Provided Value;CM-MAC=[Edited: “Personal Information”];CMTS-MAC=[Edited: “Personal Information”];CM-QOS=1.1;CM-VER=3.1; |
|
2024-10-18, 14:53:03 |
Notice (6) |
DS profile assignment change. DS Chan ID: 32; Previous Profile: ; New Profile: 1 2 3.;CM-MAC=[Edited: “Personal Information”];CMTS-MAC=[Edited: “Personal Information”];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=[Edited: “Personal Information”];CMTS-MAC=[Edited: “Personal Information”];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”];CMTS-MAC=[Edited: “Personal Information”];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”];CMTS-MAC=[Edited: “Personal Information”];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”];CMTS-MAC=[Edited: “Personal Information”];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”];CMTS-MAC=[Edited: “Personal Information”];CM-QOS=1.1;CM-VER=3.1; |
|
2024-10-18, 10:28:27 |
Critical (3) |
Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=[Edited: “Personal Information”];CMTS-MAC=[Edited: “Personal Information”];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”];CMTS-MAC=[Edited: “Personal Information”];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”];CMTS-MAC=[Edited: “Personal Information”];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”];CMTS-MAC=[Edited: “Personal Information”];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”];CMTS-MAC=[Edited: “Personal Information”];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”];CMTS-MAC=[Edited: “Personal Information”];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”];CMTS-MAC=[Edited: “Personal Information”];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”];CMTS-MAC=[Edited: “Personal Information”];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”];CMTS-MAC=[Edited: “Personal Information”];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”];CMTS-MAC=[Edited: “Personal Information”];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”];CMTS-MAC=[Edited: “Personal Information”];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”];CMTS-MAC=[Edited: “Personal Information”];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”];CMTS-MAC=[Edited: “Personal Information”];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”];CMTS-MAC=[Edited: “Personal Information”];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”];CMTS-MAC=[Edited: “Personal Information”];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”];CMTS-MAC=[Edited: “Personal Information”];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”];CMTS-MAC=[Edited: “Personal Information”];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”];CMTS-MAC=[Edited: “Personal Information”];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”];CMTS-MAC=[Edited: “Personal Information”];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”];CMTS-MAC=[Edited: “Personal Information”];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”];CMTS-MAC=[Edited: “Personal Information”];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”];CMTS-MAC=[Edited: “Personal Information”];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”];CMTS-MAC=[Edited: “Personal Information”];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”];CMTS-MAC=[Edited: “Personal Information”];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”];CMTS-MAC=[Edited: “Personal Information”];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”];CMTS-MAC=[Edited: “Personal Information”];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”];CMTS-MAC=[Edited: “Personal Information”];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”];CMTS-MAC=[Edited: “Personal Information”];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”];CMTS-MAC=[Edited: “Personal Information”];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”];CMTS-MAC=[Edited: “Personal Information”];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”];CMTS-MAC=[Edited: “Personal Information”];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”];CMTS-MAC=[Edited: “Personal Information”];CM-QOS=1.1;CM-VER=3.1; |
Best I can gather from googling or ChatGPT analysis is:
- My bonded channels' metrics are within acceptable values.
- Given that my modem restarts often, ISP issues are more likely. The recurring Timing Synchronization and Ranging errors can disrupt the connection, causing the modem to restart or lose sync. Given how frequently these are occurring in the log, there may be an issue with the connection from the modem to the ISP’s equipment, possibly due to line degradation, signal interference, or problems with the ISP’s equipment.
Two years ago I had an Xfinity tech out and they were very helpful. They updated all my cable terminations, replaced out of spec splitters and eliminated unnecessary splitters, and resolved a problem out by the street. I have double checked that all connections are still snug and the modem is getting enough ventilation.
Seems pretty likely that this is just something outside the house, and a tech visit should get to the bottom of it, right?
EG
Expert
•
107.1K Messages
1 month ago
The upstream power is on the high side and it may be intermittently fluctuating even higher to out of spec levels. That can cause random disconnects, spontaneous re-booting of the modem, speed, packet loss, latency problems, and the un-bonding of channels.
In an effort to try to obtain better connectivity / more wiggle room, check to see if there are any excess/unneeded coax cable splitters in the line leading to the modem that can be eliminated/re-configured. Any splitters that remain should be high quality and cable rated for 5-1002 MHz, bi-directional, and no gold colored garbage from Home Depot, Target, Wal-Mart, etc. Splitters should be swapped with known to be good / new ones to test.
Also check the coax cable for any damage such as cuts, nicks, abrasions, kinks, sharp bends, etc.
If there aren't any unneeded splitters that can be eliminated and if your coax wiring setup can't be reconfigured so that there is a single two-way splitter connected directly off of the drop from the street / pole with one port feeding the modem and the other port feeding the rest of the house/equipment with additional splits as needed and you've checked all the wiring and fittings for integrity and tightness and refresh them by taking them apart then check for and clean off any corrosion / oxidation on the center wire and put them back together again, then perhaps it's best to book a tech visit to investigate and correct.
Good luck with it !
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XfinityEmilyB
Official Employee
•
1.7K Messages
1 month ago
@user_3uroqk Welcome to our community forum and thank you @EG for jumping in with some awesome advice :). I rely on my internet every day and want to make sure your connection is just as dependable. The large number of T3 timeouts usually indicates an issue outside the home, assuming you've checked all coax connections to make sure they are finger tight and there's no noticeable damage on the line.
Please send a direct message by clicking the chat icon in the upper right corner of the page, click on the pen and paper icon, then enter “Xfinity Support” in the “To” section. Include your name and address so I can find the account and help you schedule an appointment with a technician.
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