Frequent T3/T4 time outs after severe weather

Hi all,

We've lived in our house for about 15 months and have had a very steady internet connection up until some recent bad weather. We had a service appointment this past weekend, where the tech replaced some connections at the house, though I haven't seen much improvement apart from scattered instances of the internet staying up for longer than normal. With the severity of the weather, I'm wondering if something isn't going wrong further up the chain from my house. The modem restarting itself briefly improves things, until it starts receiving timeouts some time later.

Logs from my modem typically look like this:

                                    Jan 01 1970 0:00:17     6-Notice     N/A     Cable Modem Reboot due to T4 timeout ;CM-MAC=<redacted>;CMTS-MAC=<redacted>;CM-QOS=1.1;CM-VER=3.0;             Jul 10 2023 10:18:53     3-Critical     R04.0     Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=<redacted>;CMTS-MAC=<redacted>;CM-QOS=1.1;CM-VER=3.0;             Jul 10 2023 10:14:45     3-Critical     R02.0     No Ranging Response received - T3 time-out;CM-MAC=<redacted>;CMTS-MAC=<redacted>;CM-QOS=1.1;CM-VER=3.0;             Jul 10 2023 10:10:02     5-Warning     Z00.0     MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1;CM-MAC=<redacted>;CMTS-MAC=<redacted>;CM-QOS=1.1;CM-VER=3.0;             Jan 01 1970 0:00:36     3-Critical     R02.0     No Ranging Response received - T3 time-out;CM-MAC=<redacted>;CMTS-MAC=<redacted>;CM-QOS=1.1;CM-VER=3.0;             Jan 01 1970 0:00:18     6-Notice     N/A     Cable Modem Reboot due to T4 timeout ;CM-MAC=<redacted>;CMTS-MAC=<redacted>;CM-QOS=1.1;CM-VER=3.0;             Jul 10 2023 10:08:33     3-Critical     R04.0     Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=<redacted>;CMTS-MAC=<redacted>;CM-QOS=1.1;CM-VER=3.0;             Jul 10 2023 10:04:33     3-Critical     R02.0     No Ranging Response received - T3 time-out;CM-MAC=<redacted>;CMTS-MAC=<redacted>;CM-QOS=1.1;CM-VER=3.0;             Jul 09 2023 21:01:40     3-Critical     R02.0     No Ranging Response received - T3 time-out;CM-MAC=<redacted>;CMTS-MAC=<redacted>;CM-QOS=1.1;CM-VER=3.0;             Jul 09 2023 21:00:27     3-Critical     R06.0     Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=<redacted>;CMTS-MAC=<redacted>;CM-QOS=1.1;CM-VER=3.0;

Edit to add some logs from today as well:



 
 
 
 
 
 
 
 
 
 
 
  
   
    
    
    
    
  
  
   
    
    Jul 12 2023 10:43:55 
    5-Warning 
    Z00.0 
    MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1;CM-MAC=<redacted>;CMTS-MAC=<redacted>;CM-QOS=1.1;CM-VER=3.0; 
    
    
    Jan 01 1970 0:00:18 
    6-Notice 
    N/A 
    Cable Modem Reboot due to T4 timeout ;CM-MAC=<redacted>;CMTS-MAC=<redacted>;CM-QOS=1.1;CM-VER=3.0; 
    
    
    Jul 12 2023 10:42:54 
    3-Critical 
    R04.0 
    Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=<redacted>;CMTS-MAC=<redacted>;CM-QOS=1.1;CM-VER=3.0; 
    
    
    Jul 12 2023 10:38:45 
    3-Critical 
    R02.0 
    No Ranging Response received - T3 time-out;CM-MAC=<redacted>;CMTS-MAC=<redacted>;CM-QOS=1.1;CM-VER=3.0; 
    
    
    Jul 12 2023 10:20:47 
    3-Critical 
    R06.0 
    Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=<redacted>;CMTS-MAC=<redacted>;CM-QOS=1.1;CM-VER=3.0; 
    
    
    Jul 12 2023 10:20:46 
    3-Critical 
    R03.0 
    Ranging Request Retries exhausted;CM-MAC=<redacted>;CMTS-MAC=<redacted>;CM-QOS=1.1;CM-VER=3.0; 
    
    
    Jul 12 2023 10:20:45 
    3-Critical 
    R02.0 
    No Ranging Response received - T3 time-out;CM-MAC=<redacted>;CMTS-MAC=<redacted>;CM-QOS=1.1;CM-VER=3.0; 
    
    
    Jul 12 2023 9:55:06 
    5-Warning 
    Z00.0 
    MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1;CM-MAC=<redacted>;CMTS-MAC=<redacted>;CM-QOS=1.1;CM-VER=3.0; 
    
    
    Jan 01 1970 0:00:25 
    3-Critical 
    R02.0 
    No Ranging Response received - T3 time-out;CM-MAC=<redacted>;CMTS-MAC=<redacted>;CM-QOS=1.1;CM-VER=3.0;

Responses

EG

Expert

•

110K Messages

2 years ago

Please also post the modem's signal stat values. Please copy all of the text in its entirety of the *Downstream Power Levels*, the *SNR's* (Signal to Noise Ratios), and the *Upstream Power Level* numbers and paste them into your next post.

0

D

dewenning

Visitor

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6 Messages

2 years ago

Sure! Here's what I currently see:

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EG

Expert

•

110K Messages

2 years ago

The signal status values at that snapshot in time were OK but the error log entries indicate that something intermittent is going on. Perhaps there is noise ingress into the line(s) / an upstream channel / return path impairment somewhere.

There are other signal stat values 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 (The Digital Care Team) who are available to these boards. They will be able to poll the CMTS (Cable Modem Termination System) to check 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 the CMTS for those upstream receive signal stats.

You should get a reply here in your topic. Good luck !

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D

dewenning

Visitor

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6 Messages

@EG Thanks so much!

2 years ago

EG

Expert

•

110K Messages

@dewenning You're quite welcome !

I am not a Comcast Employee.
I am a Customer Expert volunteering my time to help other customers here in the Forums.
We ask that you post publicly so people with similar questions may benefit from the conversation.

Was your question answered? Please mark an Accepted Answer! tick

I am not a Comcast Employee.
I am a Customer Expert volunteering my time to help other customers here in the Forums.
We ask that you post publicly so people with similar questions may benefit from the conversation.

Was your question answered? Please mark an Accepted Answer! tick

2 years ago

0

XfinitySara

Official Employee

•

1.7K Messages

2 years ago

Hey there, @dewenning! Thanks for posting your service concerns. I'm sorry to hear about the intermittent connection you've been noticing, and would love to help however I can! Reviewing our Connection Troubleshooting Tips, do you see anything needing adjustment? We just like to start in the public space in case anyone in the community has similar concerns, before we take this into a Direct (private) Message, if necessary.

1

0

EG

Expert

•

110K Messages

N.M.....

(edited)

I am not a Comcast Employee.
I am a Customer Expert volunteering my time to help other customers here in the Forums.
We ask that you post publicly so people with similar questions may benefit from the conversation.

Was your question answered? Please mark an Accepted Answer! tick

2 years ago

0

D

dewenning

Visitor

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6 Messages

2 years ago

Other than my modem being a little old (ARRIS SB6141), everything looks like it should be okay. Connections are all tight and look free from any corrosion that I can see; I don't believe there are any splitters in use (even the box look like it is just a single connection). From the last service visit we had this past weekend, I believe everything checked out just fine on the inside of the house.

1

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XfinitySara

Official Employee

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1.7K Messages

Got it. Thank you for confirming, @dewenning! Go ahead and send us a Direct Message to get started.

To send a direct message:

Ensure you are first signed in, then you will see a chat box icon at the top right of your page. Click that or follow this link here: https://forums.xfinity.com/direct-messaging
From there, click the 'New Message' icon. In the 'To' field, type 'Xfinity Support'.
Type your message in the text area that appears at the bottom of the window and hit enter to send. An official employee, such as myself or whoever is first available, will respond.

To expedite your request, we ask that you please include your name and the service address alongside a detailed summary of your request/question. Thank you!

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

2 years ago

0

EG

Expert

•

110K Messages

2 years ago

@dewenning

FWIW. This may or may not be the root cause of the problem but it should be addressed nevertheless. The SB6141 is no longer supported by them. ;

https://www.xfinity.com/support/devices#search

That doesn't mean that it won't currently function, but it will no longer receive any updates. And one day, it will no longer function on their system at all. You really should consider upgrading it to something more current / modern. Good luck !

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D

dewenning

Visitor

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6 Messages

@EG Yeah! I looked through the list and noticed it's no longer supported. It's probably time to upgrade anyhow, though it'd be nice to rule out anything else before spending the money (though I'm not sure how that can be done, so maybe it just needs done). I very much appreciate your replies!

2 years ago

0

EG

Expert

•

110K Messages

2 years ago

@dewenning

Send that direct message to Xfinity Support and let them take a look at your line stats from their end and see what they say.

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D

dewenning

Visitor

•

6 Messages

2 years ago

As a quick update, replacing my modem with something from the approved list (ARRIS SB6190) and everything has been working great ever since. I see occasional T3 timeouts in the logs for it, but have experienced no internet drop outs or modem restarts since replacing it. As a bonus, my down speed has increased from about 100Mbps to about 400Mbps when wired.

I greatly appreciate everyone's help. Thanks so much!

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Your Home Network

dewenning

Frequent T3/T4 time outs after severe weather

EG

dewenning

EG

dewenning

EG

XfinitySara

EG

dewenning

XfinitySara

EG

dewenning

EG

dewenning

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Jul 12 2023 10:43:55	5-Warning	Z00.0	MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1;CM-MAC=<redacted>;CMTS-MAC=<redacted>;CM-QOS=1.1;CM-VER=3.0;
Jan 01 1970 0:00:18	6-Notice	N/A	Cable Modem Reboot due to T4 timeout ;CM-MAC=<redacted>;CMTS-MAC=<redacted>;CM-QOS=1.1;CM-VER=3.0;
Jul 12 2023 10:42:54	3-Critical	R04.0	Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=<redacted>;CMTS-MAC=<redacted>;CM-QOS=1.1;CM-VER=3.0;
Jul 12 2023 10:38:45	3-Critical	R02.0	No Ranging Response received - T3 time-out;CM-MAC=<redacted>;CMTS-MAC=<redacted>;CM-QOS=1.1;CM-VER=3.0;
Jul 12 2023 10:20:47	3-Critical	R06.0	Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=<redacted>;CMTS-MAC=<redacted>;CM-QOS=1.1;CM-VER=3.0;
Jul 12 2023 10:20:46	3-Critical	R03.0	Ranging Request Retries exhausted;CM-MAC=<redacted>;CMTS-MAC=<redacted>;CM-QOS=1.1;CM-VER=3.0;
Jul 12 2023 10:20:45	3-Critical	R02.0	No Ranging Response received - T3 time-out;CM-MAC=<redacted>;CMTS-MAC=<redacted>;CM-QOS=1.1;CM-VER=3.0;
Jul 12 2023 9:55:06	5-Warning	Z00.0	MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1;CM-MAC=<redacted>;CMTS-MAC=<redacted>;CM-QOS=1.1;CM-VER=3.0;
Jan 01 1970 0:00:25	3-Critical	R02.0	No Ranging Response received - T3 time-out;CM-MAC=<redacted>;CMTS-MAC=<redacted>;CM-QOS=1.1;CM-VER=3.0;