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Have to reboot modem, at least daily to get my 1GIG tier. (Goes to 50mpbs download)

robby69
Frequent Visitor

Have to reboot modem, at least daily to get my 1GIG tier. (Goes to 50mpbs download)

(Have Comcast gigabit service), Max speed I get hardwired ever was 800+.  Usually hovers around 600.  Have to reboot every day or two, otherwise download speed drops to 50mbps, upload speed remains constant at 42mbps.  Rebooting modem "fixes" issue.  The speed dropping and having to do a reboot to fix it is my issue.  Got a new modem in december compatible with new gigabit service.  Old modem with 300mbs service was rock solid.

https://www.speedtest.net/my-result/d/2109f6d2-c839-481e-8ff3-915eea3ec0c8

Connection
   Startup Sequence
 

 

  
   Startup StepStatusComment
 

 



  
   Acquire Downstream Channel549000000 HzLocked
 

 


  
   Upstream ConnectionOKOperational
 

 


  
   Boot StateOKOperational
 

 



  
   Configuration FileOK 
 

 


  
   SecurityEnabledBPI+
 

 


  


   Connection Status
 

 

  
   System Up Time0 days 00h:20m:07s 
 

 


  
   Network AccessAllowed 
 

 


  


   Downstream Bonded Channels
 

 

 
 

 


  
   ChannelLock StatusModulationChannel IDFreq. (MHz)Pwr (dBmV)SNR (dB)CorrectedUncorrected
   1LockedQAM25613549.03.542.200
   2LockedQAM25610531.02.040.000
   3LockedQAM25611537.03.342.100
   4LockedQAM25612543.03.342.000
   5LockedQAM25614555.03.542.100
   6LockedQAM25615561.03.642.200
   7LockedQAM25616567.03.442.200
   8LockedQAM25617573.03.042.000
   9LockedQAM25618579.02.842.000
   10LockedQAM25619585.03.342.000
   11LockedQAM25620591.03.742.300
   12LockedQAM25621597.03.942.200
   13LockedQAM25622603.04.042.200
   14LockedQAM25623609.03.842.100
   15LockedQAM25624615.03.641.800
   16LockedQAM25625621.03.941.900
   17LockedQAM25626627.03.941.800
   18LockedQAM25627633.04.141.700
   19LockedQAM25628639.04.241.700
   20LockedQAM25629645.04.241.900
   21LockedQAM25630651.04.241.700
   22LockedQAM25631657.04.141.700
   23LockedQAM25632663.03.841.700
   24LockedQAM25633669.03.741.500
   25LockedQAM25634675.03.341.400
   26LockedQAM25635681.03.141.300
   27LockedQAM25636687.02.941.200
   28LockedQAM25637693.02.641.000
   29LockedQAM25638699.02.040.600
   30LockedQAM25639705.01.840.600
   31LockedQAM25640711.02.140.600
   32LockedOFDM PLC41762.00.939.659785650


   Upstream Bonded Channels
 

 

 
 

 


  
   ChannelLock StatusChannel TypeChannel IDSymb. Rate (Ksym/sec)Freq. (MHz)Pwr (dBmV)
   1LockedSC-QAM1512035.645.3
   2LockedSC-QAM2512029.245.3
   3LockedSC-QAM3512022.844.3
   4LockedSC-QAM4512016.444.3
   5LockedSC-QAM5256040.443.3


   Downstream Frequency Setting
 

 

  
   Downstream Frequency Select
  
 

 


  



   LAG Enable/Disable
 

 

  
   LAG(Link Aggregation Group, or Ethernet Port Bonding) Disable Enable    
 

 



  
EG
Expert

Re: Have to reboot modem, at least daily to get my 1GIG tier. (Goes to 50mpbs download)

The signal stats looked o/k at that snapshot in time. Are there any error log entries being shown ? If so, please post them in their entirety.

 

What is the exact make and model number of the modem ?



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I am a Customer Expert volunteering my time to help other customers here in the Forums.
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robby69
Frequent Visitor

Re: Have to reboot modem, at least daily to get my 1GIG tier. (Goes to 50mpbs download)

After I rebooted early this morning when it was 80mbps, it went to 700-800

Few hours later now:

Xfinity.speedtest. com showing 380mbps on 1Gig connection

Speedtest.net peaks at 600mbps then drops to 360mpbs at end of test

uploads on both are steady at 42mbps

 

Modem is Motorola MB8600 docsis 3.1 (installed earlier this year) and speeds were consistently around 800+mbps, occassionally going to 900.

 

Here is event log

Event Log

   Event Log
 

 

 
 

 


  
   Time  Priority  Description 
   Time Not Established Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=00:40:36:6f:8a:67;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
   Time Not Established Critical (3) No Ranging Response received - T3 time-out;CM-MAC=00:40:36:6f:8a:67;CMTS-MAC=00:01:5c:74:04:6e;CM-QOS=1.1;CM-VER=3.1;
   14:07:51
Wed Jan 6 2021
 Critical (3) SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=00:40:36:6f:8a:67;CMTS-MAC=00:01:5c:74:04:6e;CM-QOS=1.1;CM-VER=3.1;
   Time Not Established Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=00:40:36:6f:8a:67;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
   Time Not Established Critical (3) No Ranging Response received - T3 time-out;CM-MAC=00:40:36:6f:8a:67;CMTS-MAC=00:01:5c:74:04:6e;CM-QOS=1.1;CM-VER=3.1;
   Time Not Established Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=00:40:36:6f:8a:67;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
   Time Not Established Critical (3) No Ranging Response received - T3 time-out;CM-MAC=00:40:36:6f:8a:67;CMTS-MAC=00:01:5c:74:04:6e;CM-QOS=1.1;CM-VER=3.1;
   Time Not Established Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=00:40:36:6f:8a:67;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
   Time Not Established Critical (3) No Ranging Response received - T3 time-out;CM-MAC=00:40:36:6f:8a:67;CMTS-MAC=00:01:5c:74:04:6e;CM-QOS=1.1;CM-VER=3.1;
   Time Not Established Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=00:40:36:6f:8a:67;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
   Time Not Established Critical (3) No Ranging Response received - T3 time-out;CM-MAC=00:40:36:6f:8a:67;CMTS-MAC=00:01:5c:74:04:6e;CM-QOS=1.1;CM-VER=3.1;
   Time Not Established Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=00:40:36:6f:8a:67;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
   Time Not Established Critical (3) No Ranging Response received - T3 time-out;CM-MAC=00:40:36:6f:8a:67;CMTS-MAC=00:01:5c:74:04:6e;CM-QOS=1.1;CM-VER=3.1;
   03:51:40
Thu Jan 7 2021
 Critical (3) SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=00:40:36:6f:8a:67;CMTS-MAC=00:01:5c:74:04:6e;CM-QOS=1.1;CM-VER=3.1;
   03:51:46
Thu Jan 7 2021
 Critical (3) No Ranging Response received - T3 time-out;CM-MAC=00:40:36:6f:8a:67;CMTS-MAC=00:01:5c:74:04:6e;CM-QOS=1.1;CM-VER=3.1;
   14:51:21
Fri Jan 8 2021
 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=00:40:36:6f:8a:67;CMTS-MAC=00:01:5c:74:04:6e;CM-QOS=1.1;CM-VER=3.1;
   19:10:13
Wed Jan 13 2021
 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=00:40:36:6f:8a:67;CMTS-MAC=00:01:5c:74:04:6e;CM-QOS=1.1;CM-VER=3.1;
   04:27:31
Mon Jan 18 2021
 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=00:40:36:6f:8a:67;CMTS-MAC=00:01:5c:74:04:6e;CM-QOS=1.1;CM-VER=3.1;
   05:27:25
Tue Feb 2 2021
 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=00:40:36:6f:8a:67;CMTS-MAC=00:01:5c:74:04:6e;CM-QOS=1.1;CM-VER=3.1;
   23:45:47
Sat Feb 6 2021
 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=00:40:36:6f:8a:67;CMTS-MAC=00:01:5c:74:04:6e;CM-QOS=1.1;CM-VER=3.1;
   Time Not Established Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=00:40:36:6f:8a:67;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
   Time Not Established Critical (3) No Ranging Response received - T3 time-out;CM-MAC=00:40:36:6f:8a:67;CMTS-MAC=00:01:5c:74:04:6e;CM-QOS=1.1;CM-VER=3.1;
   16:47:01
Sun Feb 7 2021
 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=00:40:36:6f:8a:67;CMTS-MAC=00:01:5c:74:04:6e;CM-QOS=1.1;CM-VER=3.1;
   20:04:22
Mon Feb 8 2021
 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=00:40:36:6f:8a:67;CMTS-MAC=00:01:5c:74:04:6e;CM-QOS=1.1;CM-VER=3.1;
   Time Not Established Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=00:40:36:6f:8a:67;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
   Time Not Established Critical (3) No Ranging Response received - T3 time-out;CM-MAC=00:40:36:6f:8a:67;CMTS-MAC=00:01:5c:74:04:6e;CM-QOS=1.1;CM-VER=3.1;
   Time Not Established Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=00:40:36:6f:8a:67;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
   Time Not Established Critical (3) No Ranging Response received - T3 time-out;CM-MAC=00:40:36:6f:8a:67;CMTS-MAC=00:01:5c:74:04:6e;CM-QOS=1.1;CM-VER=3.1;
   Time Not Established Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=00:40:36:6f:8a:67;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
   Time Not Established Critical (3) No Ranging Response received - T3 time-out;CM-MAC=00:40:36:6f:8a:67;CMTS-MAC=00:01:5c:74:04:6e;CM-QOS=1.1;CM-VER=3.1;
   Time Not Established Notice (6) Honoring MDD; IP provisioning mode = IPv6
   07:49:41
Fri Feb 12 2021
 Notice (6) DS profile assignment change. DS Chan ID: 32; Previous Profile: ; New Profile: 1 2 3.;CM-MAC=00:40:36:6f:8a:67;CMTS-MAC=00:01:5c:74:04:6e;CM-QOS=1.1;CM-VER=3.1;
 
 
   
 
EG
Expert

Re: Have to reboot modem, at least daily to get my 1GIG tier. (Goes to 50mpbs download)

Even though the signal stats looked o/k at that snapshot in time, the error log entries confirm that something is going on. Perhaps there is noise ingress into the line(s) 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 !



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? Mark the post as Best Answer!
robby69
Frequent Visitor

Re: Have to reboot modem, at least daily to get my 1GIG tier. (Goes to 50mpbs download)

Thanks for your help.  I had 300mbps with surfboard modem and had no issues.  Only reason I wen to Gigabit was because it was $10 cheaper since I went off 1yr 300mpbs contract.  I have not had any issues with Comcast except for the occassional outage. 

EG
Expert

Re: Have to reboot modem, at least daily to get my 1GIG tier. (Goes to 50mpbs download)

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? Mark the post as Best Answer!