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T3 and T4 timeout

Frequent Visitor

T3 and T4 timeout

Xfinity community,

 

Without any changes, I experience multiple short internet disruption daily for a while. Some are couple minutes long and some are couple seconds. After some research, I replaced 1) Moto SB6121 to a brand new SB6141; 2) coax cables; 3) splitter.

 

However, I still experience similar issue after all these. Cable modem reported many T3 timeout errors and some T4 timeout errors. I tried to call Xfinity but the support only knows starting from checking if Windows applications behave right, even I have explained the cable modem log entries.

 

From the forum, T3 and T4 timeout seem to be a common issue but the reasons varies. Can someone please advise if I still have to reach Xfinity to send a technican to check outside cables?

 

 

Thanks a lot.

 

Time Priority Code Message
Aug 01 2019 20:44:27 5-Warning Z00.0 MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1;CM-MAC=78:96:84:f9:f4:31;CMTS-MAC=00:01:5c:86:26:52;CM-QOS=1.1;CM-VER=3.0;
Jan 01 1970 00:00:23 3-Critical R02.0 No Ranging Response received - T3 time-out;CM-MAC=78:96:84:f9:f4:31;CMTS-MAC=00:01:5c:86:26:52;CM-QOS=1.1;CM-VER=3.0;
Jan 01 1970 00:00:18 6-Notice N/A Cable Modem Reboot due to IP loss ;CM-MAC=78:96:84:f9:f4:31;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.0;
Aug 01 2019 20:18:16 3-Critical R02.0 No Ranging Response received - T3 time-out;CM-MAC=78:96:84:f9:f4:31;CMTS-MAC=00:01:5c:86:26:52;CM-QOS=1.1;CM-VER=3.0;
Aug 01 2019 20:16:40 3-Critical R06.0 Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=78:96:84:f9:f4:31;CMTS-MAC=00:01:5c:86:26:52;CM-QOS=1.1;CM-VER=3.0;
Aug 01 2019 20:16:40 3-Critical R03.0 Ranging Request Retries exhausted;CM-MAC=78:96:84:f9:f4:31;CMTS-MAC=00:01:5c:86:26:52;CM-QOS=1.1;CM-VER=3.0;
Aug 01 2019 20:16:15 3-Critical R02.0 No Ranging Response received - T3 time-out;CM-MAC=78:96:84:f9:f4:31;CMTS-MAC=00:01:5c:86:26:52;CM-QOS=1.1;CM-VER=3.0;
Aug 01 2019 19:59:07 3-Critical R06.0 Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=78:96:84:f9:f4:31;CMTS-MAC=00:01:5c:86:26:52;CM-QOS=1.1;CM-VER=3.0;
Aug 01 2019 19:59:07 3-Critical R03.0 Ranging Request Retries exhausted;CM-MAC=78:96:84:f9:f4:31;CMTS-MAC=00:01:5c:86:26:52;CM-QOS=1.1;CM-VER=3.0;
Aug 01 2019 19:58:41 3-Critical R02.0 No Ranging Response received - T3 time-out;CM-MAC=78:96:84:f9:f4:31;CMTS-MAC=00:01:5c:86:26:52;CM-QOS=1.1;CM-VER=3.0;
Aug 01 2019 19:37:50 3-Critical R06.0 Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=78:96:84:f9:f4:31;CMTS-MAC=00:01:5c:86:26:52;CM-QOS=1.1;CM-VER=3.0;
Aug 01 2019 19:37:50 3-Critical R03.0 Ranging Request Retries exhausted;CM-MAC=78:96:84:f9:f4:31;CMTS-MAC=00:01:5c:86:26:52;CM-QOS=1.1;CM-VER=3.0;
Aug 01 2019 19:37:25 3-Critical R02.0 No Ranging Response received - T3 time-out;CM-MAC=78:96:84:f9:f4:31;CMTS-MAC=00:01:5c:86:26:52;CM-QOS=1.1;CM-VER=3.0;
Aug 01 2019 18:31:24 3-Critical R06.0 Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=78:96:84:f9:f4:31;CMTS-MAC=00:01:5c:86:26:52;CM-QOS=1.1;CM-VER=3.0;
Aug 01 2019 18:31:24 3-Critical R03.0 Ranging Request Retries exhausted;CM-MAC=78:96:84:f9:f4:31;CMTS-MAC=00:01:5c:86:26:52;CM-QOS=1.1;CM-VER=3.0;
Aug 01 2019 18:30:59 3-Critical R02.0 No Ranging Response received - T3 time-out;CM-MAC=78:96:84:f9:f4:31;CMTS-MAC=00:01:5c:86:26:52;CM-QOS=1.1;CM-VER=3.0;
Aug 01 2019 14:29:33 5-Warning Z00.0 MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1;CM-MAC=78:96:84:f9:f4:31;CMTS-MAC=00:01:5c:86:26:52;CM-QOS=1.1;CM-VER=3.0;
Jan 01 1970 00:00:19 6-Notice N/A Cable Modem Reboot due to T4 timeout ;CM-MAC=78:96:84:f9:f4:31;CMTS-MAC=00:01:5c:86:26:52;CM-QOS=1.1;CM-VER=3.0;
Aug 01 2019 14:28:37 3-Critical R04.0 Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=78:96:84:f9:f4:31;CMTS-MAC=00:01:5c:86:26:52;CM-QOS=1.1;CM-VER=3.0;
Aug 01 2019 14:24:30 3-Critical R02.0

No Ranging Response received - T3 time-out;CM-MAC=78:96:84:f9:f4:31;CMTS-MAC=00:01:5c:86:26:52;CM-QOS=1.1;CM-VER=3.0;

 

 

 

 

Downstream Bonding Channel Value
Channel ID 22  13  16  17  18  19  20  21 
Frequency 627000000 Hz  573000000 Hz  591000000 Hz  597000000 Hz  603000000 Hz  609000000 Hz  615000000 Hz  621000000 Hz 
Signal to Noise Ratio 34 dB  36 dB  36 dB  35 dB  34 dB  35 dB  36 dB  36 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
-10 dBmV   -7 dBmV   -7 dBmV   -8 dBmV   -10 dBmV   -9 dBmV   -11 dBmV   -9 dBmV  

 

Upstream Bonding Channel Value
Channel ID
Frequency 36500000 Hz  17300000 Hz  23700000 Hz  30100000 Hz 
Ranging Service ID 9834  9834  9834  9834 
Symbol Rate 5.120 Msym/sec  5.120 Msym/sec  5.120 Msym/sec  5.120 Msym/sec 
Power Level 41 dBmV  37 dBmV  39 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 Status (Codewords) Bonding Channel Value
Channel ID 22  13  16  17  18  19  20  21 
Total Unerrored Codewords 90205996  90197206  90214015  90222585  90188007  90187009  90190968  90193020 
Total Correctable Codewords 16  17  15  17  16 
Total Uncorrectable Codewords 1114  892  1356  1421  818  1419  1555  979 
Expert

Re: T3 and T4 timeout

The downstream power is on the low / weak side and it may be intermittently fluctuating even lower 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: T3 and T4 timeout

Sounds very reasonable. I will give a try. Thanks for the suggestions.

Expert

Re: T3 and T4 timeout

Please post back with how you make out.



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Frequent Visitor

Re: T3 and T4 timeout

I noticed that from street there is a spliter to split cables to basement and second floor. At this moment, I don't have anything on the second floor so I removed the second cable from spliter but still kept spliter. The singal to noise ratio increased about 15%. Not sure if the number is more reasonable than before. Usually, T3 timeout happens every 3-4 hours, and T4 timeout happends 2-3 times a day.

 

Downstream Bonding Channel Value
Channel ID 10  11 
Frequency 519000000 Hz  525000000 Hz  531000000 Hz  537000000 Hz  543000000 Hz  549000000 Hz  555000000 Hz  561000000 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
0 dBmV   0 dBmV   0 dBmV   -1 dBmV   -1 dBmV   -1 dBmV   -1 dBmV   -1 dBmV  

 

Upstream Bonding Channel Value
Channel ID
Frequency 36500000 Hz  17300000 Hz  23700000 Hz  30100000 Hz 
Ranging Service ID 11212  11212  11212  11212 
Symbol Rate 5.120 Msym/sec  5.120 Msym/sec  5.120 Msym/sec  5.120 Msym/sec 
Power Level 51 dBmV  53 dBmV  51 dBmV  51 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 Status (Codewords) Bonding Channel Value
Channel ID 10  11 
Total Unerrored Codewords 747087273  747106473  747115472  747138215  747065485  747072252  747066005  747082454 
Total Correctable Codewords 22  330  106  15  10551  5782  9804  726 
Total Uncorrectable Codewords 667  2524  1894  607  3462  4172  7340  894 
Highlighted
Expert

Re: T3 and T4 timeout

Yeah, the downstream is better but whatever you did it made the upstream power worse...



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I am a Customer Expert volunteering my time to help other customers here in the Forums.
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Frequent Visitor

Re: T3 and T4 timeout

Since no need to use splitter, I have removed both splitters and replaced with coaxial cable connectors. Here is current data. It will take couple hours to find out if modem still timeouts or reboots.

 

Downstream Bonding Channel Value
Channel ID 14  15  16  17  18  19  20  22 
Frequency 579000000 Hz  585000000 Hz  591000000 Hz  597000000 Hz  603000000 Hz  609000000 Hz  615000000 Hz  627000000 Hz 
Signal to Noise Ratio 38 dB  38 dB  38 dB  38 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
7 dBmV   7 dBmV   7 dBmV   7 dBmV   7 dBmV   6 dBmV   6 dBmV   6 dBmV  

 

Upstream Bonding Channel Value
Channel ID
Frequency 36500000 Hz  17300000 Hz  23700000 Hz  30100000 Hz 
Ranging Service ID 8864  8864  8864  8864 
Symbol Rate 5.120 Msym/sec  5.120 Msym/sec  5.120 Msym/sec  5.120 Msym/sec 
Power Level 43 dBmV  45 dBmV  43 dBmV  43 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 Status (Codewords) Bonding Channel Value
Channel ID 14  15  16  17  18  19  20  22 
Total Unerrored Codewords 76902036  76909464  76917737  76925955  76893147  76895890  76897403  76897590 
Total Correctable Codewords 18  11  14  10  13 
Total Uncorrectable Codewords 680  1427  1341  1295  672  681  639  1450 
Expert

Re: T3 and T4 timeout

Now that's all within spec !!



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I am a Customer Expert volunteering my time to help other customers here in the Forums.
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Frequent Visitor

Re: T3 and T4 timeout

Unfortunately, still sees many T3 timeouts today. There seems to be less T4 timeout. I guess I still have to ask a technician to come. WIll post back updates if any. Thanks.