Regular Visitor
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4 Messages
Internet keeps dropping
I've been having frequent Internet drops the last week. When this happens, my Motorola MT7711 seems to have problems acquiring upstream signal. Power levels appear to be within reasonable range (40-50). Modem event log is peppered with criticals such as:
No Ranging Response received - T3 time-out
Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out
SYNC Timing Synchronization failure - Failed to acquire FEC framing
SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing
I've tried using splitters and removing all splitters, neither which work consistently. Right now I have only the feed line going into the modem, but how long it will actually function before my problems return is unknown. Any assistance would be greatly appreciated. Thank you.
BruceW
Gold Problem Solver
•
26.4K Messages
2 years ago
Network connection problems are often due to poor coax connections or damaged coax cable, usually in or near your home. Running the cable through a surge protector, a defective splitter, or too many splitters can cause signal problems as well. If there is an amplifier in the line make sure it's getting power.
If you want to troubleshoot this yourself, please see Internet Troubleshooting Tips. If you still need help, please post your Internet plan speed and the following information from your modem (from http://192.168.100.1):
Copy and pasted text is preferred over images. Be aware that, if you post any images, your message will be made Private for a time, as all images must be approved by the Forum Moderators before the messages containing them become generally visible.
If you can't find the problem or you'd rather have Comcast take care of it and an employee does not respond to your message here, call them at the phone number on your bill or 1-800-Comcast, or use one of the options on https://www.xfinity.com/support/contact-us/. It's not likely they can fix the problem remotely. If not, insist they send a tech out to identify the cause and correct it.
If the tech finds bad coax, splitters, amplifiers, or connections in your home (even if Comcast originally supplied them) you'll probably have to pay for the visit (approx $100) unless you have their Service Protection Plan ( https://www.xfinity.com/support/articles/service-protection-plan, closed to customers that don't already have it). If the trouble is due to a faulty Comcast rental device or anything outside your home you shouldn't be charged.
Please be aware that there are 2 kinds of responses in this Forum: Replies and Comments. When you Comment on a post by scrolling down to "Comment on this post here...", I am notified of your response. But if you select Reply, I am NOT notified and may not be aware of your response.
(edited)
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JR21009
Regular Visitor
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4 Messages
2 years ago
Plan speed: 1 Gbps
System Up Time
0 days 06h:59m:32s
Downstream:
Channel
Lock Status
Modulation
Channel ID
Freq. (MHz)
Pwr (dBmV)
SNR (dB)
Corrected
Uncorrected
1
Locked
QAM256
21
519.0
11.1
40.1
209
36
2
Locked
QAM256
1
387.0
9.0
39.6
382
98
3
Locked
QAM256
2
393.0
10.1
39.9
286
106
4
Locked
QAM256
3
399.0
10.1
40.0
271
106
5
Locked
QAM256
4
405.0
9.3
39.7
346
91
6
Locked
QAM256
5
411.0
9.8
39.9
321
86
7
Locked
QAM256
6
417.0
9.9
40.0
238
97
8
Locked
QAM256
7
423.0
9.4
39.9
339
86
9
Locked
QAM256
8
429.0
9.7
40.0
274
78
10
Locked
QAM256
9
435.0
10.0
40.1
232
86
11
Locked
QAM256
10
441.0
9.6
40.0
287
83
12
Locked
QAM256
11
447.0
9.8
40.0
231
103
13
Locked
QAM256
12
453.0
10.5
40.2
241
46
14
Locked
QAM256
13
459.0
10.6
40.1
184
62
15
Locked
QAM256
14
465.0
11.4
40.2
196
56
16
Locked
QAM256
15
471.0
13.1
40.6
205
26
17
Locked
QAM256
16
477.0
12.1
41.5
246
25
18
Locked
QAM256
17
483.0
11.3
41.3
191
34
19
Locked
QAM256
18
489.0
12.3
41.6
205
26
20
Locked
QAM256
19
495.0
11.5
41.3
226
48
21
Locked
QAM256
20
513.0
11.4
41.5
191
29
22
Locked
QAM256
22
525.0
11.9
41.4
224
13
23
Locked
QAM256
23
531.0
10.9
41.2
182
48
24
Locked
QAM256
24
537.0
10.6
41.0
195
58
Total
5902
1527
Upstream
Channel
Lock Status
Channel Type
Channel ID
Symb. Rate (Ksym/sec)
Freq. (MHz)
Pwr (dBmV)
1
Locked
ATDMA
4
5120
29.2
44.3
2
Locked
ATDMA
2
5120
16.3
44.5
3
Locked
ATDMA
3
5120
22.8
44.0
4
Locked
ATDMA
5
5120
35.6
44.5
5
Locked
ATDMA
6
2560
40.4
45.0
6
Not Locked
Unknown
0
0
0
0.0
7
Not Locked
Unknown
0
0
0
0.0
8
Not Locked
Unknown
0
0
0
0.0
Time
Priority
Description
Fri Sep 15 05:50:28 2023
Critical (3)
No Ranging Response received - T3 time-out;CM-MAC=XX:XX:XX:XX:XX:XX;CMTS-MAC=XX:XX:XX:XX:XX:XX;CM-QOS=1.0;CM-VER=3.0;
Fri Sep 15 05:51:43 2023
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=1.0;CM-VER=3.0;
Fri Sep 15 05:51:54 2023
Critical (3)
No Ranging Response received - T3 time-out;CM-MAC=XX:XX:XX:XX:XX:XX;CMTS-MAC=XX:XX:XX:XX:XX:XX;CM-QOS=1.0;CM-VER=3.0;
Fri Sep 15 05:52:01 2023
Critical (3)
SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=XX:XX:XX:XX:XX:XX;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0;
Fri Sep 15 05:52:26 2023
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=1.0;CM-VER=3.0;
Fri Sep 15 05:52:27 2023
Critical (3)
SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=XX:XX:XX:XX:XX:XX;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0;
Fri Sep 15 05:52:28 2023
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=1.0;CM-VER=3.0;
Fri Sep 15 05:52:37 2023
Notice (6)
Honoring MDD; IP provisioning mode = IPv6
Time Not Established
Critical (3)
No Ranging Response received - T3 time-out;CM-MAC=XX:XX:XX:XX:XX:XX;CMTS-MAC=XX:XX:XX:XX:XX:XX;CM-QOS=1.0;CM-VER=3.0;
Time Not Established
Critical (3)
SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=XX:XX:XX:XX:XX:XX;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0;
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=1.0;CM-VER=3.0;
Time Not Established
Critical (3)
No Ranging Response received - T3 time-out;CM-MAC=XX:XX:XX:XX:XX:XX;CMTS-MAC=XX:XX:XX:XX:XX:XX;CM-QOS=1.0;CM-VER=3.0;
Time Not Established
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=1.0;CM-VER=3.0;
Time Not Established
Critical (3)
No Ranging Response received - T3 time-out;CM-MAC=XX:XX:XX:XX:XX:XX;CMTS-MAC=XX:XX:XX:XX:XX:XX;CM-QOS=1.0;CM-VER=3.0;
Time Not Established
Critical (3)
SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=XX:XX:XX:XX:XX:XX;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0;
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=1.0;CM-VER=3.0;
Time Not Established
Critical (3)
No Ranging Response received - T3 time-out;CM-MAC=XX:XX:XX:XX:XX:XX;CMTS-MAC=XX:XX:XX:XX:XX:XX;CM-QOS=1.0;CM-VER=3.0;
Time Not Established
Warning (5)
B-INIT-RNG Failure - Retries exceeded;CM-MAC=XX:XX:XX:XX:XX:XX;CMTS-MAC=XX:XX:XX:XX:XX:XX;CM-QOS=1.0;CM-VER=3.0;
Time Not Established
Critical (3)
No Ranging Response received - T3 time-out;CM-MAC=XX:XX:XX:XX:XX:XX;CMTS-MAC=XX:XX:XX:XX:XX:XX;CM-QOS=1.0;CM-VER=3.0;
Time Not Established
Warning (5)
B-INIT-RNG Failure - Retries exceeded;CM-MAC=XX:XX:XX:XX:XX:XX;CMTS-MAC=XX:XX:XX:XX:XX:XX;CM-QOS=1.0;CM-VER=3.0;
Time Not Established
Critical (3)
No Ranging Response received - T3 time-out;CM-MAC=XX:XX:XX:XX:XX:XX;CMTS-MAC=XX:XX:XX:XX:XX:XX;CM-QOS=1.0;CM-VER=3.0;
Time Not Established
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=1.0;CM-VER=3.0;
Time Not Established
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=1.0;CM-VER=3.0;
Time Not Established
Critical (3)
No Ranging Response received - T3 time-out;CM-MAC=XX:XX:XX:XX:XX:XX;CMTS-MAC=XX:XX:XX:XX:XX:XX;CM-QOS=1.0;CM-VER=3.0;
Time Not Established
Warning (5)
B-INIT-RNG Failure - Retries exceeded;CM-MAC=XX:XX:XX:XX:XX:XX;CMTS-MAC=XX:XX:XX:XX:XX:XX;CM-QOS=1.0;CM-VER=3.0;
Time Not Established
Critical (3)
No Ranging Response received - T3 time-out;CM-MAC=XX:XX:XX:XX:XX:XX;CMTS-MAC=XX:XX:XX:XX:XX:XX;CM-QOS=1.0;CM-VER=3.0;
Time Not Established
Warning (5)
B-INIT-RNG Failure - Retries exceeded;CM-MAC=XX:XX:XX:XX:XX:XX;CMTS-MAC=XX:XX:XX:XX:XX:XX;CM-QOS=1.0;CM-VER=3.0;
Time Not Established
Critical (3)
No Ranging Response received - T3 time-out;CM-MAC=XX:XX:XX:XX:XX:XX;CMTS-MAC=XX:XX:XX:XX:XX:XX;CM-QOS=1.0;CM-VER=3.0;
Time Not Established
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=1.0;CM-VER=3.0;
Time Not Established
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=1.0;CM-VER=3.0;
Time Not Established
Critical (3)
No Ranging Response received - T3 time-out;CM-MAC=XX:XX:XX:XX:XX:XX;CMTS-MAC=XX:XX:XX:XX:XX:XX;CM-QOS=1.0;CM-VER=3.0;
Time Not Established
Critical (3)
SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=XX:XX:XX:XX:XX:XX;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0;
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=1.0;CM-VER=3.0;
Time Not Established
Critical (3)
No Ranging Response received - T3 time-out;CM-MAC=XX:XX:XX:XX:XX:XX;CMTS-MAC=XX:XX:XX:XX:XX:XX;CM-QOS=1.0;CM-VER=3.0;
Time Not Established
Critical (3)
SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=XX:XX:XX:XX:XX:XX;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0;
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=1.0;CM-VER=3.0;
Time Not Established
Critical (3)
No Ranging Response received - T3 time-out;CM-MAC=XX:XX:XX:XX:XX:XX;CMTS-MAC=XX:XX:XX:XX:XX:XX;CM-QOS=1.0;CM-VER=3.0;
Time Not Established
Notice (6)
Honoring MDD; IP provisioning mode = IPv6
Time Not Established
Critical (3)
No Ranging Response received - T3 time-out;CM-MAC=XX:XX:XX:XX:XX:XX;CMTS-MAC=XX:XX:XX:XX:XX:XX;CM-QOS=1.0;CM-VER=3.0;
Time Not Established
Notice (6)
Honoring MDD; IP provisioning mode = IPv6
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0
BruceW
Gold Problem Solver
•
26.4K Messages
2 years ago
You didn't post the modem model number, but whatever it is, it isn't approved for Gigabit service -- no 24 channel modem is. Please see https://www.xfinity.com/support/devices. The signal levels and SNR values posted look good, the event log not so much. I suspect that there are other problems, but there's really not much point in going after them until you either replace the modem with a model approved for Gigabit, or reduce your plan speed to one for which the device is approved.
Good luck!
Please be aware that there are 2 kinds of responses in this Forum: Replies and Comments. When you Comment on a post by scrolling down to "Comment on this post here...", I am notified of your response. But if you select Reply, I am NOT notified and may not be aware of your response.
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JR21009
Regular Visitor
•
4 Messages
2 years ago
Model number was in my initial post - Motorola MT7711. It was supported when I bought it and it's worked fine for more than 3.5 years. That doesn't necessarily mean that it hasn't developed a problem, but since cable modems w/ voice aren't cheap I'm trying to consider the more inexpensive possibilities first. The feed coming into my house is also about 21 years old now (I'm the original owner), so maybe that's a factor. I'm very capable when it comes to troubleshooting, but some things are out of my hands, sadly. Thank you for looking everything over, though.
(edited)
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BruceW
Gold Problem Solver
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26.4K Messages
2 years ago
Apologies for overlooking that. Comcast rates the MT7711 for use with plan speeds "Up to 864 Mbps". Unless you're in a situation where Gigabit is cheaper then 800 Mbps, I'd give switching to that speed a try. Couldn't hurt!
Please be aware that there are 2 kinds of responses in this Forum: Replies and Comments. When you Comment on a post by scrolling down to "Comment on this post here...", I am notified of your response. But if you select Reply, I am NOT notified and may not be aware of your response.
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