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user_775752
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3 Messages

Tuesday, January 11th, 2022

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T3 and T4 Timeout errors

Hello,

I am having issues with my internet connection dropping multiple times each day.  The logs in my modem are showing T3 .  I've tried contacting support via chat.  I was told that the "server team" did something to resolve it, but the issue has continued to persist.

I have a Motorola MB7621 Cable Modem.  Device information is below:

Device Information

 

 

   Cable Specification Version

DOCSIS 3.0

   Hardware Version

V1.0

   Software Version

7621-5.7.1.7

   Cable Modem MAC Address

[Edited: "Personal Information"]

   Cable Modem Serial Number

1300-MB7621-30-2222

   CM Certificate

Installed

   

5.7.1mp4

Below are the logs

Log

 


  

 Time 

 Priority 

 Description 

 Mon Jan 10 17:53:37 2022  

 Critical (3) 

 Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.0; 

 Mon Jan 10 17:57:57 2022  

 Critical (3) 

 Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.0; 

 Mon Jan 10 17:58:07 2022  

 Critical (3) 

 No Ranging Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; 

 Mon Jan 10 18:55:25 2022  

 Critical (3) 

 Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.0; 

 Mon Jan 10 18:55:25 2022  

 Critical (3) 

 Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.0; 

 Mon Jan 10 18:55:25 2022  

 Critical (3) 

 16 consecutive T3 timeouts while trying to range on upstream channel 0;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.0; 

 Mon Jan 10 18:55:35 2022  

 Critical (3) 

 Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.0; 

 Mon Jan 10 18:55:35 2022  

 Critical (3) 

 Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.0; 

 Mon Jan 10 18:55:35 2022  

 Critical (3) 

 16 consecutive T3 timeouts while trying to range on upstream channel 4;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.0; 

 Mon Jan 10 18:56:11 2022  

 Critical (3) 

 Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.0; 

 Mon Jan 10 18:56:11 2022  

 Critical (3) 

 Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.0; 

 Mon Jan 10 18:56:11 2022  

 Critical (3) 

 16 consecutive T3 timeouts while trying to range on upstream channel 3;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.0; 

 Mon Jan 10 18:56:48 2022  

 Critical (3) 

 Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.0; 

 Mon Jan 10 18:56:48 2022  

 Critical (3) 

 Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.0; 

 Mon Jan 10 18:56:48 2022  

 Critical (3) 

 16 consecutive T3 timeouts while trying to range on upstream channel 2;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.0; 

 Mon Jan 10 18:59:12 2022  

 Critical (3) 

 Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.0; 

 Mon Jan 10 19:26:45 2022  

 Critical (3) 

 Resetting the cable modem due to docsDevResetNow 

 Time Not Established 

 Critical (3) 

 No Ranging Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; 

 Time Not Established 

 Notice (6) 

 Honoring MDD; IP provisioning mode = IPv6 

 Mon Jan 10 21:21:59 2022  

 Critical (3) 

 Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.0; 

 Mon Jan 10 21:21:59 2022  

 Critical (3) 

 Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.0; 

 Mon Jan 10 21:21:59 2022  

 Critical (3) 

 16 consecutive T3 timeouts while trying to range on upstream channel 1;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.0; 

 Mon Jan 10 21:22:24 2022  

 Critical (3) 

 Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.0; 

 Mon Jan 10 21:22:24 2022  

 Critical (3) 

 Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.0; 

 Mon Jan 10 21:22:24 2022  

 Critical (3) 

 16 consecutive T3 timeouts while trying to range on upstream channel 0;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.0; 

 Mon Jan 10 21:22:43 2022  

 Critical (3) 

 Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.0; 

 Mon Jan 10 21:22:43 2022  

 Critical (3) 

 Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.0; 

 Mon Jan 10 21:22:43 2022  

 Critical (3) 

 16 consecutive T3 timeouts while trying to range on upstream channel 4;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.0; 

 Mon Jan 10 21:22:58 2022  

 Critical (3) 

 Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.0; 

 Mon Jan 10 21:27:18 2022  

 Critical (3) 

 Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.0; 

 Mon Jan 10 21:27:28 2022  

 Critical (3) 

 No Ranging Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.0;CM-VER=3.0; 

 Mon Jan 10 21:27:37 2022  

 Notice (6) 

 Honoring MDD; IP provisioning mode = IPv6 

See below for signal information

 Downstream Bonded Channels

 


  

   Channel

Lock Status

Modulation

Channel ID

Freq. (MHz)

Pwr (dBmV)

SNR (dB)

Corrected

Uncorrected

1

Locked

QAM256

9

573.0

10.1

42.8

24672

342

2

Locked

QAM256

10

579.0

10.0

42.9

17803

273

3

Locked

QAM256

11

585.0

10.1

42.9

5647

226

4

Locked

QAM256

12

591.0

9.5

42.5

21626

224

5

Locked

QAM256

13

597.0

9.1

42.4

16407

306

6

Locked

QAM256

14

603.0

9.5

42.6

4502

203

7

Locked

QAM256

15

609.0

9.0

42.3

23841

359

8

Locked

QAM256

16

615.0

8.9

42.2

7740

225

9

Locked

QAM256

17

621.0

8.7

42.1

10150

172

10

Locked

QAM256

18

627.0

8.8

42.1

21161

243

11

Locked

QAM256

19

633.0

8.8

42.1

2972

155

12

Locked

QAM256

20

639.0

8.4

41.5

10497

172

13

Locked

QAM256

21

645.0

8.7

41.5

8952

197

14

Locked

QAM256

22

651.0

8.6

42.0

7672

133

15

Locked

QAM256

23

657.0

8.7

42.2

3547

116

16

Locked

QAM256

24

663.0

8.7

42.3

7969

266

17

Locked

QAM256

25

669.0

8.5

43.3

6678

265

18

Locked

QAM256

26

675.0

8.3

43.3

15662

447

19

Locked

QAM256

27

681.0

8.6

43.3

2168

237

20

Locked

QAM256

28

687.0

9.1

43.0

3800

211

21

Locked

QAM256

29

693.0

8.6

43.6

20702

457

22

Locked

QAM256

30

699.0

9.0

43.4

2764

283

23

Locked

QAM256

31

705.0

9.3

43.7

2421

245

24

Locked

QAM256

32

711.0

9.4

43.6

2701

199

Total

 

 

 

 

 

 

252054

5956

Upstream Bonded Channels

 


  

   Channel

Lock Status

Channel Type

Channel ID

Symb. Rate (Ksym/sec)

Freq. (MHz)

Pwr (dBmV)

1

Locked

ATDMA

10

2560

40.4

41.5

2

Locked

ATDMA

8

5120

16.4

43.3

3

Locked

ATDMA

7

5120

22.8

43.3

4

Locked

ATDMA

6

5120

29.2

43.5

5

Locked

ATDMA

5

5120

35.6

43.3

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

Question

 • 

Updated 

4 years ago

 • Edited

980

2

0

Oldest First
Selected Oldest First

Accepted Solution

EG

Expert

 • 

112.2K Messages

4 years ago

The downstream power is a bit on the high side but I'm not certain that it is the root cause of the problem.

The error log entries confirm that something is going on. Perhaps there is noise ingress into the line(s) / an upstream channel-return path impairment 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 !

4

user_775752

Visitor

 • 

3 Messages

@EG Thank you for your help!

4 years ago

0

EG

Expert

 • 

112.2K Messages

@user_775752

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

4 years ago

0

user_60eb20

Visitor

 • 

1 Message

any update on this? Was this resolved? I have the same (or similar) issue.

4 years ago

0

EG

Expert

 • 

112.2K Messages

@user_60eb20

Please create a new topic of your own here on this board detailing your issue. Thanks. 

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

4 years ago

0

EG

Expert

 • 

112.2K Messages

4 years ago

Please redact all of the CM MAC and the CMTS MAC addresses in your error log entries for your privacy.  They are considered to be personal information. Personally identifying information is a violation of their forum guidelines. The forum bot will not allow your post to be seen publically. It flagged your post as "Private".

2

0

user_775752

Visitor

 • 

3 Messages

4 years ago

0

CCKorie

Problem Solver

 • 

1.1K Messages

Hey there, @user_775752. 

 

We appreciate all the information provided and the logs. I'd be happy to help look into the issues. Can you send me a DM with your name and address? 

 

• Click the "Direct Messaging" icon or https://comca.st/3iVtu1B

• Click the "New message" (pencil and paper) icon

• The "To:" line prompts you to "Type the name of a person", but don't do that.

Instead, type "Xfinity Support" there. As you are typing a drop-down list appears.

• Select "Xfinity Support" from the list. An "Xfinity Support" graphic replaces the "To:" line.

• Type your message in the text area near the bottom of the window

• Press Enter or tap the > icon to send it any of those platforms will be able to assist. :)

I no longer work for Comcast.

4 years ago

0

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