Community Forum

Lots of T3 timeouts; unlocked upstream channels; frequent disconnects

Highlighted
New Poster

Lots of T3 timeouts; unlocked upstream channels; frequent disconnects

Hi all. I have gigabit service (1000/35), with a moto mb8600 modem. 

 

Downstream speeds generally seem fine. Upload has always been below spec -- generally between 10-20mbs.

 

In the last few months, we've had increasingly frequent connection drops -- I have to reboot the modem, which can take multiple attemts, and usually takes 5+ minutes to reconnect.

 

I (finally) decided to look into it. The modem logs are filled with T3 timeout errors:

 

  15:51:44
Fri Jul 17 2020
  Critical (3)   16 consecutive T3 timeouts while trying to range on upstream channel 2;CM-MAC=00:40:36:4f:70:9c;CMTS-MAC=00:01:5c:79:38:55;CM-QOS=1.1;CM-VER=3.1;
    15:51:54
Fri Jul 17 2020
  Critical (3)   No Ranging Response received - T3 time-out;CM-MAC=00:40:36:4f:70:9c;CMTS-MAC=00:01:5c:79:38:55;CM-QOS=1.1;CM-VER=3.1;
    15:51:54
Fri Jul 17 2020
  Critical (3)   Ranging Request Retries exhausted;CM-MAC=00:40:36:4f:70:9c;CMTS-MAC=00:01:5c:79:38:55;CM-QOS=1.1;CM-VER=3.1;
    15:51:54
Fri Jul 17 2020
  Critical (3)   16 consecutive T3 timeouts while trying to range on upstream channel 1;CM-MAC=00:40:36:4f:70:9c;CMTS-MAC=00:01:5c:79:38:55;CM-QOS=1.1;CM-VER=3.1;
    15:54:39
Fri Jul 17 2020
  Critical (3)   No Ranging Response received - T3 time-out;CM-MAC=00:40:36:4f:70:9c;CMTS-MAC=00:01:5c:79:38:55;CM-QOS=1.1;CM-VER=3.1;
    15:54:39
Fri Jul 17 2020
  Critical (3)   Ranging Request Retries exhausted;CM-MAC=00:40:36:4f:70:9c;CMTS-MAC=00:01:5c:79:38:55;CM-QOS=1.1;CM-VER=3.1;
    15:54:39
Fri Jul 17 2020
  Critical (3)   16 consecutive T3 timeouts while trying to range on upstream channel 3;CM-MAC=00:40:36:4f:70:9c;CMTS-MAC=00:01:5c:79:38:55;CM-QOS=1.1;CM-VER=3.1;
    15:54:40
Fri Jul 17 2020
  Critical (3)   No Ranging Response received - T3 time-out;CM-MAC=00:40:36:4f:70:9c;CMTS-MAC=00:01:5c:79:38:55;CM-QOS=1.1;CM-VER=3.1;
 

 

and so forth -- this is constant. The connection page describes 4 upstream channels, only one of which is locked:



   Upstream Bonded Channels
 

 

 
 

 


  
   Channel Lock Status Channel Type Channel ID Symb. Rate (Ksym/sec) Freq. (MHz) Pwr (dBmV)
   1 Not Locked SC-QAM 93 5120 17.3 35.8
   2 Not Locked SC-QAM 94 5120 23.7 44.8
   3 Not Locked SC-QAM 95 5120 30.1 39.5
   4 Locked SC-QAM 96 5120 36.5 46.3

 

 

power levels fluctuate a bit, and I've seen them above 50.

 

We just have internet, so a single cable enters the house and runs to the modem; no splitters, etc. There's a longish cable run accross my backyard (been there for 20+ years at least; predates us being in the house). I suspect that old cable was damaged in a storm at some point. 

 

Anyone have suggestions, or guidance on how to quickly get talking to a tech support person?