Skip to main content
MtnIceBox
1st Topic
1st Reply

Visitor

 • 

3 Messages

Tuesday, April 26th, 2022 4:28 PM

Closed

Critical T3 time-outs

Hello,

I have a Motorola MB8600 modem and am having issues with frequent internet disconnects, some which require restarting the modem. I checked our event log and see multiple daily Critical T3 time-outs. I would like to have an Xfinity service provider out to my home to fix the line. Please advise. I have pasted a portion of the event log below.

Event Log  
  
    Time    Priority    Description 
    07:18:16
Tue Apr 26 2022		   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;
    07:18:19
Tue Apr 26 2022		   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;
    07:18:26
Tue Apr 26 2022		   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;
    07:18:32
Tue Apr 26 2022		   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;
    07:18:32
Tue Apr 26 2022		   Critical (3)   Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
    07:18:32
Tue Apr 26 2022		   Critical (3)   16 consecutive T3 timeouts while trying to range on upstream channel 3;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
    07:18:56
Tue Apr 26 2022		   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;
    07:19:04
Tue Apr 26 2022		   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;
    07:19:06
Tue Apr 26 2022		   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;
    07:19:17
Tue Apr 26 2022		   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;
    07:19:17
Tue Apr 26 2022		   Critical (3)   Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
    07:19:17
Tue Apr 26 2022		   Critical (3)   16 consecutive T3 timeouts while trying to range on upstream channel 2;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
    07:20:05
Tue Apr 26 2022		   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;

Question

 • 

Updated 

4 years ago

 • Edited

292

6

0

This conversation is no longer open for comments or replies and is no longer visible to community members.

Oldest First
Selected Oldest First
EG

Expert

 • 

118.3K Messages

4 years ago

Please also 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

0

MtnIceBox

Visitor

 • 

3 Messages

4 years ago

 Downstream Bonded Channels  
  
   Channel Lock Status Modulation Channel ID Freq. (MHz) Pwr (dBmV) SNR (dB) Corrected Uncorrected
   1 Locked QAM256 20 495.0 -6.9 37.3 1261 431
   2 Locked QAM256 17 477.0 -6.6 37.2 1273 436
   3 Locked QAM256 18 483.0 -6.7 37.3 1115 430
   4 Locked QAM256 19 489.0 -7.2 37.1 1116 385
   5 Locked QAM256 21 507.0 -6.5 37.5 830 327
   6 Locked QAM256 22 513.0 -6.2 37.7 765 314
   7 Locked QAM256 23 519.0 -6.2 37.9 704 337
   8 Locked QAM256 24 525.0 -6.1 38.0 674 308
   9 Locked QAM256 25 531.0 -6.0 37.8 711 358
   10 Locked QAM256 26 543.0 -6.2 38.1 605 325
   11 Locked QAM256 27 549.0 -6.5 37.9 491 304
   12 Locked QAM256 28 555.0 -7.1 37.8 481 366
   13 Locked QAM256 29 561.0 -7.1 37.5 551 350
   14 Locked QAM256 30 567.0 -7.0 37.5 566 369
   15 Locked QAM256 31 573.0 -6.8 37.7 541 350
   16 Locked QAM256 32 579.0 -5.4 38.4 455 292
   17 Locked QAM256 33 585.0 -4.6 38.9 325 253
   18 Locked QAM256 34 591.0 -4.2 39.0 285 278
   19 Locked QAM256 35 597.0 -4.2 39.0 326 246
   20 Locked QAM256 36 603.0 -4.4 38.9 314 275
   21 Locked QAM256 37 609.0 -4.2 39.1 242 245
   22 Locked QAM256 38 615.0 -4.3 39.1 222 252
   23 Locked QAM256 39 621.0 -3.7 39.4 189 254
   24 Locked QAM256 40 627.0 -3.1 39.9 166 249
   25 Locked QAM256 41 633.0 -2.9 40.0 191 246
   26 Locked QAM256 42 639.0 -3.1 39.8 180 239
   27 Locked QAM256 43 645.0 -3.3 39.6 207 281
   28 Locked QAM256 44 651.0 -4.9 38.4 236 287
   29 Locked QAM256 45 657.0 -5.7 38.3 277 319
   30 Locked QAM256 46 663.0 -5.0 38.8 217 320
   31 Locked QAM256 47 669.0 -4.4 39.3 226 315
   32 Locked OFDM PLC 48 722.0 -3.6 0.0 67301357 912109


   Upstream Bonded Channels  
  
   Channel Lock Status Channel Type Channel ID Symb. Rate (Ksym/sec) Freq. (MHz) Pwr (dBmV)
   1 Locked SC-QAM 7 2560 10.4 47.8
   2 Locked SC-QAM 8 5120 16.4 48.0
   3 Locked SC-QAM 9 5120 22.8 48.8
   4 Locked SC-QAM 10 5120 29.2 49.0
   5 Locked SC-QAM 11 5120 35.6 48.0
   6 Locked SC-QAM 12 2560 40.4 48.8

0

0

EG

Expert

 • 

118.3K Messages

4 years ago

The upstream power is on the high side and it may be intermittently fluctuating even higher to out of spec levels. And the downstream power is on the low / weak side as well. 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 there 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 5-1000 MHz, bi-directional, and no gold colored garbage from Radio Shack, Home Depot, Target, 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, 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 !

1

0

MtnIceBox

Visitor

 • 

3 Messages

@EG​ Ok, thank you for the response. I will give all that a try, and yes, we only have one splitter from the wall to the modem/TV box. I will try replacing it with a new one to see if that helps. Xfinity is coming for a support visit tomorrow, so we'll see if they have any solutions.

4 years ago

0

EG

Expert

 • 

118.3K Messages

4 years ago

Bear in mind that if the premises facing techs can not find or fix a problem at your home, it is they who are responsible for escalating it to their line / network / maintenance dept. techs. The problem may lie beyond your home in the local neighborhood infrastructure somewhere but it is their S.O.P. to start at the home. And if the problem is found to be on their side of the demarcation point, there will not be any charge.

Please post back here with how things turn out.

0

0

user_7add69

Visitor

 • 

2 Messages

4 years ago

I have a SurfBoard 8200 and same issue and the techs can not figure it out.  I think the upstream levels are high as you (EG) stated for other users.  Please have a look:

Startup Procedure
Procedure Status Comment
Acquire Downstream Channel 669000000 Hz Locked
Connectivity State OK Operational
Boot State OK Operational
Configuration File OK 
Security Enabled BPI+
DOCSIS Network Access Enabled Allowed 
Downstream Bonded Channels
Channel ID Lock Status Modulation Frequency Power SNR/MER Corrected Uncorrectables
42 Locked QAM256 669000000 Hz 2.6 dBmV 40.9 dB 1129 2032
14 Locked QAM256 495000000 Hz 0.9 dBmV 41.4 dB 7594 13967
15 Locked QAM256 507000000 Hz 1.0 dBmV 41.5 dB 10011 20705
16 Locked QAM256 513000000 Hz 1.2 dBmV 41.5 dB 8903 19939
17 Locked QAM256 519000000 Hz 1.5 dBmV 41.6 dB 10776 20863
18 Locked QAM256 525000000 Hz 1.5 dBmV 41.7 dB 13442 29384
19 Locked QAM256 531000000 Hz 1.8 dBmV 41.8 dB 15848 39772
20 Locked QAM256 537000000 Hz 1.9 dBmV 41.7 dB 16157 45843
21 Locked QAM256 543000000 Hz 1.9 dBmV 41.7 dB 18300 53371
22 Locked QAM256 549000000 Hz 2.0 dBmV 41.7 dB 14311 36138
23 Locked QAM256 561000000 Hz 1.9 dBmV 41.6 dB 16619 40104
24 Locked QAM256 567000000 Hz 1.9 dBmV 41.6 dB 17632 57786
25 Locked Other 693000000 Hz 2.8 dBmV 39.0 dB 3972662369 8966
26 Not Locked QAM256 0 Hz 0.0 dBmV 41.5 dB 16875 46608
27 Locked QAM256 573000000 Hz 1.7 dBmV 41.6 dB 10160 23202
28 Locked QAM256 579000000 Hz 1.8 dBmV 41.4 dB 6411 18608
29 Locked QAM256 585000000 Hz 2.1 dBmV 41.4 dB 7311 20886
30 Locked QAM256 591000000 Hz 2.0 dBmV 41.3 dB 9223 24442
31 Locked QAM256 597000000 Hz 2.1 dBmV 41.4 dB 11042 29703
32 Locked QAM256 603000000 Hz 2.4 dBmV 41.3 dB 10773 30153
33 Locked QAM256 609000000 Hz 2.1 dBmV 40.8 dB 8687 25884
34 Locked QAM256 615000000 Hz 2.2 dBmV 41.2 dB 7904 24034
35 Locked QAM256 621000000 Hz 2.4 dBmV 41.2 dB 7882 24692
36 Locked QAM256 627000000 Hz 2.2 dBmV 41.1 dB 8062 25488
37 Locked QAM256 633000000 Hz 2.5 dBmV 41.2 dB 7803 26052
38 Locked QAM256 639000000 Hz 2.3 dBmV 41.4 dB 7804 24597
39 Locked QAM256 645000000 Hz 2.4 dBmV 41.2 dB 9799 26385
40 Locked QAM256 651000000 Hz 2.6 dBmV 41.1 dB 8383 23642
41 Locked QAM256 657000000 Hz 2.5 dBmV 41.0 dB 9799 27894
43 Locked QAM256 663000000 Hz 2.5 dBmV 40.3 dB 10142 27244
44 Locked QAM256 675000000 Hz 2.1 dBmV 40.9 dB 9965 26047
45 Locked QAM256 681000000 Hz 2.4 dBmV 40.9 dB 10726 26669


Upstream Bonded Channels
Channel Channel ID Lock Status US Channel Type Frequency Width Power
1 73 Locked SC-QAM Upstream 36500000 Hz 6400000 Hz 49.0 dBmV
2 74 Locked SC-QAM Upstream 30100000 Hz 6400000 Hz 49.0 dBmV
3 75 Locked SC-QAM Upstream 23700000 Hz 6400000 Hz 48.0 dBmV
4 76 Locked SC-QAM Upstream 17300000 Hz 6400000 Hz 48.0 dBmV


Current System Time: Wed Jul 27 18:04:55 2022

0

0

EG

Expert

 • 

118.3K Messages

4 years ago

Yes, they are on the high side. Have you tried any of the advice that I gave to the original poster @MtnIceBox ?

I wonder how the original poster @MtnIceBox made out ?

2

0

user_7add69

Visitor

 • 

2 Messages

@EG​ I wonder that as well.

Yes, I tried several and no change.  Xfinity showed up and now running at slower speed and not a word from them on the issue nor the fix. 

I have modem logs documenting the multiple  T3s before each and every drop but who at xfinity cares?  Not by "supervisor" so we will see if anyone on this forum responds.  Very disappointing the number of T3 errors here but the techs show up and are not aware.

4 years ago

0

CCStephanieT

Contributor

 • 

342 Messages

Hello @user_7add69  Could you please send our team a direct message with your full name and full address? Our team can most definitely take a further look at this issue.

To send a "Direct Message" to Xfinity Support:

Click "Sign In" if necessary

Click the "Direct Messaging" icon or https://comca.st/3EqVMu7

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

The "To:" line prompts you to "Type the name of a person". Instead, type "Xfinity Support" there

 - As you are typing a drop-down list appears. Select "Xfinity Support" from that list

 - An "Xfinity Support" graphic replaces the "To:" line

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

Press Enter to send it

 

See https://comca.st/3KQF8q9 for an example.

I no longer work for Comcast. 

4 years ago

0

forum icon

New to the Community?

Start Here