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Intermittent T3 Timeouts and Drops

Frequent Visitor

Intermittent T3 Timeouts and Drops

For the past month Xfinity Internet has been slow several times per day with dropped ping packets to Comcast dns server. Modem is SB6141 that I own which was replaced today with another SB6141. Both modems show the same symptoms. PC connected directly to modem shows same symptoms.

 

Comcast phone support reports no problems from her end.

 

Suggestions?

 

 

Modem Log 

Apr 29 2019 11:38:03 3-Critical R02.0 No Ranging Response received - T3 time-out;CM-MAC=20:3d:66:08:cb:6b;CMTS-MAC=00:01:5c:b2:a2:73;CM-QOS=1.1;CM-VER=3.0;
Apr 29 2019 11:37:38 3-Critical R06.0 Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=20:3d:66:08:cb:6b;CMTS-MAC=00:01:5c:b2:a2:73;CM-QOS=1.1;CM-VER=3.0;
Apr 29 2019 11:37:38 3-Critical R03.0 Ranging Request Retries exhausted;CM-MAC=20:3d:66:08:cb:6b;CMTS-MAC=00:01:5c:b2:a2:73;CM-QOS=1.1;CM-VER=3.0;
Apr 29 2019 11:37:37 3-Critical R02.0 No Ranging Response received - T3 time-out;CM-MAC=20:3d:66:08:cb:6b;CMTS-MAC=00:01:5c:b2:a2:73;CM-QOS=1.1;CM-VER=3.0;
Apr 29 2019 11:36:42 3-Critical R06.0 Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=20:3d:66:08:cb:6b;CMTS-MAC=00:01:5c:b2:a2:73;CM-QOS=1.1;CM-VER=3.0;
Apr 29 2019 11:36:42 3-Critical R03.0 Ranging Request Retries exhausted;CM-MAC=20:3d:66:08:cb:6b;CMTS-MAC=00:01:5c:b2:a2:73;CM-QOS=1.1;CM-VER=3.0;
Apr 29 2019 11:36:40 3-Critical R02.0 No Ranging Response received - T3 time-out;CM-MAC=20:3d:66:08:cb:6b;CMTS-MAC=00:01:5c:b2:a2:73;CM-QOS=1.1;CM-VER=3.0;
Apr 29 2019 07:32:37 5-Warning Z00.0 MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1;CM-MAC=20:3d:66:08:cb:6b;CMTS-MAC=00:01:5c:b2:a2:73;CM-QOS=1.1;CM-VER=3.0;
Jan 01 1970 00:00:15 6-Notice N/A Cable Modem Reboot due to power reset ;CM-MAC=20:3d:66:08:cb:6b;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.0;
Apr 29 2019 07:21:26 5-Warning Z00.0 MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1;CM-MAC=20:3d:66:08:cb:6b;CMTS-MAC=00:01:5c:b2:a2:73;CM-QOS=1.1;CM-VER=3.0;
Jan 01 1970 00:00:19 3-Critical R02.0 No Ranging Response received - T3 time-out;CM-MAC=20:3d:66:08:cb:6b;CMTS-MAC=00:01:5c:b2:a2:73;CM-QOS=1.1;CM-VER=3.0;
Jan 01 1970 00:00:15 6-Notice N/A Cable Modem Reboot from shell ;CM-MAC=20:3d:66:08:cb:6b;CMTS-MAC=00:01:5c:b2:a2:73;CM-QOS=1.1;CM-VER=3.0;
Apr 29 2019 07:20:34 6-Notice E112.0 SW download Successful - Via Config file
Downstream Bonding Channel Value
Channel ID 12  11  14  15  16  17  18  19 
Frequency 531000000 Hz  525000000 Hz  543000000 Hz  555000000 Hz  561000000 Hz  567000000 Hz  573000000 Hz  579000000 Hz 
Signal to Noise Ratio 38 dB  38 dB  38 dB  38 dB  38 dB  38 dB  38 dB  38 dB 
Downstream Modulation QAM256  QAM256  QAM256  QAM256  QAM256  QAM256  QAM256  QAM256 
Power Level -3 dBmV   -3 dBmV   -3 dBmV   -3 dBmV   -2 dBmV   -2 dBmV   -2 dBmV   -2 dBmV  

 

Upstream Bonding Channel Value
Channel ID
Frequency 35600000 Hz  29200000 Hz  22800000 Hz  16000000 Hz 
Ranging Service ID 10048  10048  10048  10048 
Symbol Rate 5.120 Msym/sec  5.120 Msym/sec  5.120 Msym/sec  5.120 Msym/sec 
Power Level 49 dBmV  50 dBmV  48 dBmV  46 dBmV 
Upstream Modulation [2] QPSK
[1] 32QAM
[3] 64QAM
 
[2] QPSK
[1] 32QAM
[3] 64QAM
 
[2] QPSK
[1] 32QAM
[3] 64QAM
 
[2] QPSK
[1] 32QAM
[3] 64QAM
 
Ranging Status Success  Success  Success  Success 

 

Signal Stats (Codewords) Bonding Channel Value
Channel ID 12  11  14  15  16  17  18  19 
Total Unerrored Codewords 1043315543  1043323923  1043332404  1043340587  1043309519  1043310549  1043312919  1043323378 
Total Correctable Codewords 547  698  885  1198  507  1001  835  1026 
Total Uncorrectable Codewords 4817  6704  6225  6271  6684  6159  6328  6256 

 

Expert

Re: Intermittent T3 Timeouts and Drops

The upstream power is approaching the high side and it may be intermittently fluctuating even higher to out of spec levels. That can cause random disconnects, spontaneous re-booting of the modem, and speed and latency problems.

In a self troubleshooting 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 5-1002 MHz, bi-directional, and no gold colored garbage types like GE, RadioShack, RCA, Philips, Leviton, Magnavox, and Rocketfish from big box stores like Home Depot, Lowes, Target, Wal-Mart etc. Splitters should be swapped with known to be good / new ones to test

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.



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Frequent Visitor

Re: Intermittent T3 Timeouts and Drops

Thanks for the helpful response. I removed one splitter (Holland brand Silver colored I believe) and now have the modem directly connected to the Comcast input. No T3 timeouts since I did this.

 

Do the upstream power levels (updated below) still seem high?

 

I will call Comcast to inquire about  "Upstream Rx Power" (Upstream Receive Power Level), the "Upstream SNR Ch." (Upstream Signal To Noise Ratio), and the "Upstream ICFR" (In Channel Frequency Response) and post those when I have them.

 

Here are the new signal levels after connecting the modem directly to the Comcast feed.

Downstream Bonding Channel Value
Channel ID 22  23  25  26  28  29  30  31 
Frequency 597000000 Hz  603000000 Hz  615000000 Hz  621000000 Hz  633000000 Hz  639000000 Hz  645000000 Hz  651000000 Hz 
Signal to Noise Ratio 38 dB  39 dB  38 dB  38 dB  38 dB  38 dB  38 dB  38 dB 
Downstream Modulation QAM256  QAM256  QAM256  QAM256  QAM256  QAM256  QAM256  QAM256 
Power Level 2 dBmV   2 dBmV   1 dBmV   1 dBmV   0 dBmV   0 dBmV   0 dBmV   0 dBmV  

 

Upstream Bonding Channel Value
Channel ID
Frequency 35600000 Hz  29200000 Hz  22800000 Hz  16000000 Hz 
Ranging Service ID 13214  13214  13214  13214 
Symbol Rate 5.120 Msym/sec  5.120 Msym/sec  5.120 Msym/sec  5.120 Msym/sec 
Power Level 43 dBmV  44 dBmV  42 dBmV  41 dBmV 
Upstream Modulation [2] QPSK
[1] 32QAM
[3] 64QAM
 
[2] QPSK
[1] 32QAM
[3] 64QAM
 
[2] QPSK
[1] 32QAM
[3] 64QAM
 
[2] QPSK
[1] 32QAM
[3] 64QAM
 
Ranging Status Success  Success  Success  Success 

 

Signal Stats (Codewords) Bonding Channel Value
Channel ID 22  23  25  26  28  29  30  31 
Total Unerrored Codewords 1630638798  1630655394  1630647235  1630663548  1630630827  1630632017  1630633005  1630633972 
Total Correctable Codewords 177  148  213  182  188  167  178  201 
Total Uncorrectable Codewords 1687  1377  1292  1379  1570  1467  1552  1623 
Expert

Re: Intermittent T3 Timeouts and Drops


@DOCEDOC123 wrote:

 

Do the upstream power levels (updated below) still seem high?


Looks good. Good luck !



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Official Employee

Re: Intermittent T3 Timeouts and Drops

Hello, All. I have not heard back from you. If you still need assistance, please feel free to start a new thread.


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Frequent Visitor

Re: Intermittent T3 Timeouts and Drops

Here is an update. Symptoms persist since original post. During Internet rush hours (6-9 am and 5-9 pm) connection is unusable for most activites. Othertimes it varies from responsive to sluggish.

 

As of 24-May with PC connected directly to SB6141 modem and modem connected directly to Comcast demark with no splitters.

  • Using http://speedtest.xfinity.com/  Down 6.6 Mbps Up 0.4 Mbps Latency 320 ms Woodstock Ga
  • Per Xfinity support Upstream SNR 35.3 Upstream Receive power = -0.1 ICFR = 41
Downstream Bonding Channel Value
Channel ID 23  20  21  22  24  25  26  27 
Frequency 603000000 Hz  585000000 Hz  591000000 Hz  597000000 Hz  609000000 Hz  615000000 Hz  621000000 Hz  627000000 Hz 
Signal to Noise Ratio 39 dB  39 dB  39 dB  38 dB  39 dB  39 dB  38 dB  39 dB 
Downstream Modulation QAM256  QAM256  QAM256  QAM256  QAM256  QAM256  QAM256  QAM256 
Power Level 1 dBmV   2 dBmV   2 dBmV   1 dBmV   1 dBmV   1 dBmV   0 dBmV   0 dBmV  

 

Upstream Bonding Channel Value
Channel ID
Frequency 35800000 Hz  29400000 Hz  23000000 Hz  16600000 Hz 
Ranging Service ID 12138  12138  12138  12138 
Symbol Rate 5.120 Msym/sec  5.120 Msym/sec  5.120 Msym/sec  5.120 Msym/sec 
Power Level 44 dBmV  44 dBmV  43 dBmV  41 dBmV 
Upstream Modulation [2] QPSK
[1] 32QAM
[3] 64QAM
 
[2] QPSK
[1] 32QAM
[3] 64QAM
 
[2] QPSK
[1] 32QAM
[3] 64QAM
 
[2] QPSK
[1] 32QAM
[3] 64QAM
 
Ranging Status Success  Success  Success  Success 

 

Signal Stats (Codewords) Bonding Channel Value
Channel ID 23  20  21  22  24  25  26  27 
Total Unerrored Codewords 115758315  115191558  115199833  115208025  115174934  115175931  115177100  115178712 
Total Correctable Codewords 22  10  27  59  26  20 
Total Uncorrectable Codewords 3109  1493  1402  1396  1481  1533  1477  1395 

 

 

Frequent Visitor

Re: Intermittent T3 Timeouts and Drops

Modem log shows fewer T3 timeouts since connecting directly to Comcast demark. Powercycling modem sometimes helps improve thruput though that may be my imagination.

Time Priority Code Message
May 24 2019 06:44:46 5-Warning Z00.0 MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1;CM-MAC=20:3d:66:08:cb:6b;CMTS-MAC=00:01:5c:b2:a2:73;CM-QOS=1.1;CM-VER=3.0;
Jan 01 1970 00:00:20 3-Critical R02.0 No Ranging Response received - T3 time-out;CM-MAC=20:3d:66:08:cb:6b;CMTS-MAC=00:01:5c:b2:a2:73;CM-QOS=1.1;CM-VER=3.0;
Jan 01 1970 00:00:15 6-Notice N/A Cable Modem Reboot due to power reset ;CM-MAC=20:3d:66:08:cb:6b;CMTS-MAC=00:01:5c:b2:a2:73;CM-QOS=1.1;CM-VER=3.0;
May 24 2019 05:51:33 5-Warning Z00.0 MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1;CM-MAC=20:3d:66:08:cb:6b;CMTS-MAC=00:01:5c:b2:a2:73;CM-QOS=1.1;CM-VER=3.0;
Jan 01 1970 00:00:18 3-Critical R02.0 No Ranging Response received - T3 time-out;CM-MAC=20:3d:66:08:cb:6b;CMTS-MAC=00:01:5c:b2:a2:73;CM-QOS=1.1;CM-VER=3.0;
Jan 01 1970 00:00:14 6-Notice N/A Cable Modem Reboot due to power reset ;CM-MAC=20:3d:66:08:cb:6b;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.0;
May 24 2019 04:39:40 5-Warning Z00.0 MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1;CM-MAC=20:3d:66:08:cb:6b;CMTS-MAC=00:01:5c:b2:a2:73;CM-QOS=1.1;CM-VER=3.0;
Jan 01 1970 00:00:20 3-Critical R02.0 No Ranging Response received - T3 time-out;CM-MAC=20:3d:66:08:cb:6b;CMTS-MAC=00:01:5c:b2:a2:73;CM-QOS=1.1;CM-VER=3.0;
Jan 01 1970 00:00:15 6-Notice N/A Cable Modem Reboot due to IP loss ;CM-MAC=20:3d:66:08:cb:6b;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.0;
May 24 2019 03:35:46 5-Warning Z00.0 MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1;CM-MAC=20:3d:66:08:cb:6b;CMTS-MAC=00:01:5c:b2:a2:73;CM-QOS=1.1;CM-VER=3.0;
Jan 01 1970 00:00:21 3-Critical R02.0 No Ranging Response received - T3 time-out;CM-MAC=20:3d:66:08:cb:6b;CMTS-MAC=00:01:5c:b2:a2:73;CM-QOS=1.1;CM-VER=3.0;
Jan 01 1970 00:00:15 6-Notice N/A Cable Modem Reboot due to power reset ;CM-MAC=20:3d:66:08:cb:6b;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.0;
May 10 2019 06:48:42 5-Warning Z00.0 MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1;CM-MAC=20:3d:66:08:cb:6b;CMTS-MAC=00:01:5c:b2:a2:73;CM-QOS=1.1;CM-VER=3.0;
Frequent Visitor

Re: Intermittent T3 Timeouts and Drops

Despite everything looking good about the modem, T3 Timeouts and Drops continue. Trying to use the Internet is painful as the connection is dropped or thruput slows to a crawl.

Time Priority Code Message
May 30 2019 00:42:55 5-Warning Z00.0 MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1;CM-MAC=20:3d:66:08:cb:6b;CMTS-MAC=00:01:5c:b2:a2:73;CM-QOS=1.1;CM-VER=3.0;
May 30 2019 00:42:09 3-Critical R02.0 No Ranging Response received - T3 time-out;CM-MAC=20:3d:66:08:cb:6b;CMTS-MAC=00:01:5c:b2:a2:73;CM-QOS=1.1;CM-VER=3.0;
May 30 2019 00:38:42 3-Critical D11.1 TFTP Request Retries exceeded, CM unable to register
May 30 2019 00:38:42 3-Critical D05.0 TFTP failed - Request sent - No Response;CM-MAC=20:3d:66:08:cb:6b;CMTS-MAC=00:01:5c:b2:a2:73;CM-QOS=1.1;CM-VER=3.0;
Jan 01 1970 00:16:53 3-Critical R02.0 No Ranging Response received - T3 time-out;CM-MAC=20:3d:66:08:cb:6b;CMTS-MAC=00:01:5c:b2:a2:73;CM-QOS=1.1;CM-VER=3.0;
Jan 01 1970 00:12:54 5-Warning R09.0 B-INIT-RNG Failure - Retries exceeded;CM-MAC=20:3d:66:08:cb:6b;CMTS-MAC=00:01:5c:b2:a2:73;CM-QOS=1.1;CM-VER=3.0;
Jan 01 1970 00:12:05 3-Critical R02.0 No Ranging Response received - T3 time-out;CM-MAC=20:3d:66:08:cb:6b;CMTS-MAC=00:01:5c:b2:a2:73;CM-QOS=1.1;CM-VER=3.0;
Jan 01 1970 00:00:15 6-Notice N/A Cable Modem Reboot due to T4 timeout ;CM-MAC=20:3d:66:08:cb:6b;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.0;
May 30 2019 00:20:40 3-Critical R04.0 Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=20:3d:66:08:cb:6b;CMTS-MAC=00:01:5c:b2:a2:73;CM-QOS=1.1;CM-VER=3.0;
May 30 2019 00:17:24 5-Warning T202.0 Lost MDD Timeout;CM-MAC=20:3d:66:08:cb:6b;CMTS-MAC=00:01:5c:b2:a2:73;CM-QOS=1.1;CM-VER=3.0;
May 30 2019 00:17:01 3-Critical T05.0 SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=20:3d:66:08:cb:6b;CMTS-MAC=00:01:5c:b2:a2:73;CM-QOS=1.1;CM-VER=3.0;
May 29 2019 20:26:45 3-Critical R02.0 No Ranging Response received - T3 time-out;CM-MAC=20:3d:66:08:cb:6b;CMTS-MAC=00:01:5c:b2:a2:73;CM-QOS=1.1;CM-VER=3.0;
May 29 2019 20:26:32 3-Critical T05.0 SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=20:3d:66:08:cb:6b;CMTS-MAC=00:01:5c:b2:a2:73;CM-QOS=1.1;CM-VER=3.0;
May 29 2019 14:29:00 3-Critical R02.0 No Ranging Response received - T3 time-out;CM-MAC=20:3d:66:08:cb:6b;CMTS-MAC=00:01:5c:b2:a2:73;CM-QOS=1.1;CM-VER=3.0;
May 29 2019 14:28:58 5-Warning Z00.0 MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1;CM-MAC=20:3d:66:08:cb:6b;CMTS-MAC=00:01:5c:b2:a2:73;CM-QOS=1.1;CM-VER=3.0;
Jan 01 1970 00:00:36 3-Critical R02.0 No Ranging Response received - T3 time-out;CM-MAC=20:3d:66:08:cb:6b;CMTS-MAC=00:01:5c:b2:a2:73;CM-QOS=1.1;CM-VER=3.0;
Jan 01 1970 00:00:15 6-Notice N/A Cable Modem Reboot due to T4 timeout ;CM-MAC=20:3d:66:08:cb:6b;CMTS-MAC=00:01:5c:b2:a2:73;CM-QOS=1.1;CM-VER=3.0;
May 29 2019 14:27:36 3-Critical R04.0 Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=20:3d:66:08:cb:6b;CMTS-MAC=00:01:5c:b2:a2:73;CM-QOS=1.1;CM-VER=3.0;
May 29 2019 14:23:37 6-Notice N/A MDD Recovery following MDD Loss;CM-MAC=20:3d:66:08:cb:6b;CMTS-MAC=00:01:5c:b2:a2:73;CM-QOS=1.1;CM-VER=3.0;
May 29 2019 14:23:02 3-Critical R04.0 Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=20:3d:66:08:cb:6b;CMTS-MAC=00:01:5c:b2:a2:73;CM-QOS=1.1;CM-VER=3.0;
Frequent Visitor

Re: Intermittent T3 Timeouts and Drops

Downstream Bonding Channel Value
Channel ID 34  35  36  37 
Frequency 453000000 Hz  459000000 Hz  465000000 Hz  471000000 Hz  477000000 Hz  483000000 Hz  489000000 Hz  495000000 Hz 
Signal to Noise Ratio 39 dB  39 dB  39 dB  39 dB  39 dB  39 dB  39 dB  39 dB 
Downstream Modulation QAM256  QAM256  QAM256  QAM256  QAM256  QAM256  QAM256  QAM256 
Power Level
The Downstream Power Level reading is a snapshot taken at the time this page was requested. Please Reload/Refresh this Page for a new reading
2 dBmV   2 dBmV   2 dBmV   2 dBmV   1 dBmV   1 dBmV   1 dBmV   1 dBmV  

 

Upstream Bonding Channel Value
Channel ID
Frequency 35800000 Hz  29400000 Hz  23000000 Hz  16600000 Hz 
Ranging Service ID 10467  10467  10467  10467 
Symbol Rate 5.120 Msym/sec  5.120 Msym/sec  5.120 Msym/sec  5.120 Msym/sec 
Power Level 44 dBmV  44 dBmV  43 dBmV  41 dBmV 
Upstream Modulation [2] QPSK
[1] 32QAM
[3] 64QAM
 
[2] QPSK
[1] 32QAM
[3] 64QAM
 
[2] QPSK
[1] 32QAM
[3] 64QAM
 
[2] QPSK
[1] 32QAM
[3] 64QAM
 
Ranging Status Success  Success  Success  Success 

 

Signal Stats (Codewords) Bonding Channel Value
Channel ID 34  35  36  37 
Total Unerrored Codewords 8394298379  8394313787  8394305783  8394322066  8394288908  8394290109  8394291306  8394293155 
Total Correctable Codewords 94  99  91  158  142  194  160  172 
Total Uncorrectable Codewords 716  1620  1453  1464  1649  1466  1636  817 
Highlighted
Expert

Re: Intermittent T3 Timeouts and Drops

You told me via PM's that you were in contact with Comcast Michael concerning this. Try PM'ing him again about it. If you can't get in touch with him I will re -escalate the issue.



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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? Mark the post as Best Answer!
Frequent Visitor

Re: Intermittent T3 Timeouts and Drops

Thanks for the reply.  Comcast is scheduling a tech on site to investigate woes upstream of their demarkation point.

 

I will post an update when (if) this is resolved.

Frequent Visitor

Re: Intermittent T3 Timeouts and Drops

Comcast tech on site found poor signal quality coming to Comcast demark. He replaced connection from house to street and the grounding block. He will ask maintenance to keep an eye on the Comcast equipment and connections outside the house to detect signal ingress.

 

No problems found with connection between grounding block and cable modem.

 

Cable modem signal after tech visit.

Downstream

Signal to Noise Ratio    37 dB       38 dB       38 dB       37 dB     38 dB  38 dB   38 dB  37 dB

Power Level 5 dBmV 5 dBmV  5 dBmV 5 dBmV 5 dBmV 5 dBmV 5 dBmV 5 dBmV 

Upstream

Power Level        36 dBmV         36 dBmV         36 dBmV         36 dBmV

Official Employee

Re: Intermittent T3 Timeouts and Drops

Thanks for providing the tech visit detail, DOCEDOC123. Please monitor the performance of your internet and report back and continued issues. We're here to confirm the issue is mitigated. 


I am an Official Comcast Employee.
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.
Was your question answered? Mark the post as Best Answer!
Frequent Visitor

Re: Intermittent T3 Timeouts and Drops

No disconnects since tech on-site visit. VPN connections to other sites now stable for 72 hours; previously VPN would drop after an hour or so. Upload and download speed match Comcast plans.

 

Lessons learned

  • Use the forum for initial troubleshooting especially if you own the cable modem. Comcast phone support repeatedly said nothing was wrong on Comcast end. Other than offering to reset my modem they were ineffective at troubleshooting. Their only solution was to dispatch a tech and potentailly charge me, depending on what was discovered. Not my idea of a robust troubleshooting approach.
  • Prior to a tech visit, simplify the signal distribution  (remove splitters) and test with modem connected directly to Comcast grounding block. This reduces the chance that problems in your side of the network will confuse the issue. Consider temporarily moving the modem to the comcast enclosure and test signal and thru put with a laptop.
  • Use an effective speed test site (not Comcast's). Look at the graphs of  download, upload and ping patterns. Comcast speed test said no problems whereas the graphs from https://sourceforge.net/speedtest/ showed repeated stalls in upload and download.
  • Explain the history and troubleshooting to the onsite tech. My tech said the work order comments had no history or advice. When he heard my tale of woe, he immediately focused on the Comcast side of the network.
  • Be prepared to persist. Resolution took two months. I was out of town some some of that is mine. Check the forum and private messages for replies. Otherwise  time slips by.

Kudos to the Comcast employees who helped me via the forum. 

Frequent Visitor

Re: Intermittent T3 Timeouts and Drops

And thanks to  @EG who started me on the path with a terrific troubleshooting approach.

Official Employee

Re: Intermittent T3 Timeouts and Drops

Glad to hear that things are working so well, DOCEDOC123. Thanks for providing a public update here. Let us know if you end up needing any additional support. 


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Expert

Re: Intermittent T3 Timeouts and Drops


@DOCEDOC123 wrote:

And thanks to  @EG who started me on the path with a terrific troubleshooting approach.


Quite welcome ! Smiley Happy



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