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T3 and T4 timeouts

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Frequent Visitor

T3 and T4 timeouts

I have been having multiple t3 and t4 timeouts a day, the issue didn’t start until last month, Comcast he replace all lines and connections, netgear support (I have a nighthawk C7800) says everything is working on the modem what could be causing this?? Is this due to the increased usage during the pandemic or should I look I to having my in wall wiring replaced (it’s only 6 months old)?
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Expert

Re: T3 and T4 timeouts

What do the modem's signal stats look like ? Try getting them here http://192.168.100.1 or here http://10.0.0.1

Please post the *Downstream Power Level*, the *Upstream Power Level*, and the *SNR* (Signal to Noise Ratio) numbers.




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Frequent Visitor

Re: T3 and T4 timeouts

Procedure Status Comment
Acquire Downstream Channel 507000000 Hz Locked
Connectivity State OK Operational
Boot State OK Operational
Security ENABLED BPI+
IP Provisioning Mode Honor MDD IPv6 only
Downstream Bonded Channels
Channel Lock Status Modulation Channel ID Frequency Power SNR Correctables Uncorrectabables
1 Locked QAM256 5 507000000 Hz 4.3 dBmV 40.2 dB 0 0
2 Locked QAM256 1 477000000 Hz 4.6 dBmV 40.0 dB 0 0
3 Locked QAM256 2 483000000 Hz 4.6 dBmV 40.2 dB 0 0
4 Locked QAM256 3 489000000 Hz 4.4 dBmV 40.0 dB 0 0
5 Locked QAM256 4 495000000 Hz 4.4 dBmV 40.0 dB 0 0
6 Locked QAM256 6 513000000 Hz 4.2 dBmV 40.1 dB 0 0
7 Locked QAM256 7 519000000 Hz 4.2 dBmV 40.2 dB 0 0
8 Locked QAM256 8 525000000 Hz 3.8 dBmV 40.1 dB 0 0
9 Locked QAM256 9 531000000 Hz 3.5 dBmV 40.0 dB 0 0
10 Locked QAM256 10 537000000 Hz 3.4 dBmV 39.7 dB 0 0
11 Locked QAM256 11 543000000 Hz 3.3 dBmV 39.9 dB 0 0
12 Locked QAM256 12 549000000 Hz 2.9 dBmV 39.8 dB 0 0
13 Locked QAM256 13 555000000 Hz 2.9 dBmV 39.3 dB 0 0
14 Locked QAM256 14 561000000 Hz 2.8 dBmV 39.5 dB 0 0
15 Locked QAM256 15 567000000 Hz 2.5 dBmV 39.4 dB 0 0
16 Locked QAM256 16 573000000 Hz 2.7 dBmV 39.7 dB 0 0
17 Locked QAM256 17 579000000 Hz 2.4 dBmV 39.5 dB 0 0
18 Locked QAM256 18 585000000 Hz 2.5 dBmV 39.4 dB 0 0
19 Locked QAM256 19 591000000 Hz 2.9 dBmV 39.8 dB 0 0
20 Locked QAM256 33 453000000 Hz 4.7 dBmV 40.1 dB 0 0
21 Locked QAM256 34 459000000 Hz 4.7 dBmV 40.1 dB 0 0
22 Locked QAM256 35 465000000 Hz 4.8 dBmV 40.0 dB 0 0
23 Locked QAM256 36 471000000 Hz 4.5 dBmV 40.1 dB 0 0
24 Locked QAM256 38 429000000 Hz 5.2 dBmV 40.2 dB 0 0
25 Locked QAM256 39 435000000 Hz 5.0 dBmV 40.1 dB 0 0
26 Locked QAM256 40 441000000 Hz 5.0 dBmV 40.1 dB 0 0
27 Locked QAM256 41 447000000 Hz 4.9 dBmV 40.1 dB 0 0
28 Locked QAM256 42 405000000 Hz 5.3 dBmV 40.6 dB 0 0
29 Locked QAM256 43 411000000 Hz 5.3 dBmV 40.4 dB 0 0
30 Locked QAM256 44 417000000 Hz 5.0 dBmV 40.2 dB 0 0
31 Locked QAM256 45 423000000 Hz 4.9 dBmV 40.1 dB 0 0
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 4 5120 Ksym/sec 16600000 Hz 41.8 dBmV
2 Locked ATDMA 1 5120 Ksym/sec 35800000 Hz 42.8 dBmV
3 Locked ATDMA 2 5120 Ksym/sec 29400000 Hz 42.8 dBmV
4 Locked ATDMA 3 5120 Ksym/sec 23000000 Hz 42.3 dBmV
5 Not Locked Unknown 0 0 Ksym/sec 0 Hz 0 dBmV
6 Not Locked Unknown 0 0 Ksym/sec 0 Hz 0 dBmV
7 Not Locked Unknown 0 0 Ksym/sec 0 Hz 0 dBmV
8 Not Locked Unknown 0 0 Ksym/sec 0 Hz 0 dBmV
Downstream OFDM Channels
Channel Channel ID Indicator Subcarrier Zero Frequency Active Subcarrier Number Range Total Codewords Uncorrectable Codewords
1 37 Non-Primary 611600000 Hz 1228 ~ 2867 751263 0
2 0 Other 0 Hz 0 ~ 0 0 0
Upstream OFDMA Channels
Channel UpstreamIsMuted Ranging Status Subcarrier Zero Frequency Active Subcarrier Number Range Symbols Per Frame Tx Power
1 Other 0 Hz 0 ~ 0 0 0 dBmV
2 Other 0 Hz 0 ~ 0 0 0 dBmV
Current System Time: Sat, Jul 04, 2020 15:32:09
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Frequent Visitor

Re: T3 and T4 timeouts

I posted my modems readings I got over 25 t3 and t4 errros from midnight to 9 am I did not have a single issue until Comcast buried a new line under my drive way, this has since been replaced but the problem continues
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Expert

Re: T3 and T4 timeouts

The stats are fine. Are you actually having any connection problems, or are you just focusing on the error log entries ?



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Frequent Visitor

Re: T3 and T4 timeouts

I’m actually dropping connection anywhere from 5-15 times a day
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Frequent Visitor

Re: T3 and T4 timeouts

I have 30 + t3 and t4 error codes from today alone
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Expert

Re: T3 and T4 timeouts

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) 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 !



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Re: T3 and T4 timeouts

Thank you!!!!
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Official Employee

Re: T3 and T4 timeouts

Hi @Marlowwebb25

 

We appreciate you for using the Xfinity Forum to bring this to our attention. I apologize for the experience you're having. I know first hand how this can be an inconvenience and would like to investigate this to help get your connection issues resolved. 

 

To get started, please send me a private message with your first and last name and the street numbers associated with your address. To send a private message, click on "ComcastChe" and then click send a message. 


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Official Employees are from multiple teams within Comcast: CARE, Product, Leadership. We ask that you post publicly so people with similar questions may benefit from the conversation.
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