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Intermittent Dropping of Internet

denonsix2
Regular Visitor

Intermittent Dropping of Internet

About twice a day I drop my internet signal for about 2 minutes - the cable modem resets itself and then the connection comes back up. I am using approved 3rd party modems and have actually replaced it (with new Motorola MB8600).

 

I occasionally see the following in the logs:

  09:57:59
Sat Aug 8 2020
 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=00:40:36:61:5f:92;CMTS-MAC=00:01:5c:9d:d6:74;CM-QOS=1.1;CM-VER=3.1;
   09:58:00
Sat Aug 8 2020
 Critical (3) 

No Ranging Response received - T3 time-out;CM-MAC=00:40:36:61:5f:92;CMTS-MAC=00:01:5c:9d:d6:74;CM-QOS=1.1;CM-VER=3.1;

or

 10:32:47
Sat Aug 8 2020
 Notice (6) CM-STATUS message sent. Event Type Code: 16; Chan ID: 48; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 3.;CM-MAC=00:40:36:61:5f:92;CMTS-MAC=00:01:5c:9d:d6:74;CM-QOS=1.1;CM-VER=3.1;

 

Would anyone mind analyzing the signal levels here and let me know if you see any red flags?

 

Downstream Bonded Channels
 

 

 
 

 


  
   ChannelLock StatusModulationChannel IDFreq. (MHz)Pwr (dBmV)SNR (dB)CorrectedUncorrected
   1LockedQAM25620525.03.840.900
   2LockedQAM2568453.05.741.900
   3LockedQAM2569459.05.741.800
   4LockedQAM25610465.05.641.700
   5LockedQAM25611471.05.741.700
   6LockedQAM25612477.05.441.600
   7LockedQAM25613483.05.441.500
   8LockedQAM25614489.05.141.300
   9LockedQAM25615495.05.141.300
   10LockedQAM25616501.04.941.200
   11LockedQAM25617507.04.841.200
   12LockedQAM25618513.04.541.100
   13LockedQAM25619519.04.241.100
   14LockedQAM25621531.03.640.700
   15LockedQAM25622537.03.540.700
   16LockedQAM25623543.03.340.700
   17LockedQAM25624549.03.140.500
   18LockedQAM25625555.03.140.500
   19LockedQAM25626561.03.040.500
   20LockedQAM25627567.02.840.300
   21LockedQAM25628573.02.840.300
   22LockedQAM25629579.02.540.000
   23LockedQAM25630585.02.740.200
   24LockedQAM25631591.02.239.800
   25LockedQAM25632597.02.339.900
   26LockedQAM25633603.02.139.700
   27LockedQAM25634609.01.739.600
   28LockedQAM25635615.01.939.800
   29LockedQAM25636621.01.239.300
   30LockedQAM25637627.01.539.400
   31LockedQAM25638633.00.538.900
   32LockedOFDM PLC48722.00.335.8380765040



   Upstream Bonded Channels
 

 

 
 

 


  
   ChannelLock StatusChannel TypeChannel IDSymb. Rate (Ksym/sec)Freq. (MHz)Pwr (dBmV)
   1LockedSC-QAM5512036.133.8
   2LockedSC-QAM6512029.633.8
   3LockedSC-QAM7512023.033.5
   4LockedSC-QAM8512016.532.8
EG
Expert

Re: Intermittent Dropping of Internet

The signal stats are o/k. Are there any more error log entries being shown ? If so, please post them as well.



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I am a Customer Expert volunteering my time to help other customers here in the Forums.
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denonsix2
Regular Visitor

Re: Intermittent Dropping of Internet

Thanks for the response!

Here's the full log I have. I did complete a power cycle around the last couple of entries, but the majority of these critical logs are what I see when I get drops intermittmently.

 

  Time  Priority  Description 
   09:57:59
Sat Aug 8 2020
 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=00:40:36:61:5f:92;CMTS-MAC=00:01:5c:9d:d6:74;CM-QOS=1.1;CM-VER=3.1;
   09:58:00
Sat Aug 8 2020
 Critical (3) No Ranging Response received - T3 time-out;CM-MAC=00:40:36:61:5f:92;CMTS-MAC=00:01:5c:9d:d6:74;CM-QOS=1.1;CM-VER=3.1;
   09:58:00
Sat Aug 8 2020
 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=00:40:36:61:5f:92;CMTS-MAC=00:01:5c:9d:d6:74;CM-QOS=1.1;CM-VER=3.1;
   09:58:09
Sat Aug 8 2020
 Critical (3) No Ranging Response received - T3 time-out;CM-MAC=00:40:36:61:5f:92;CMTS-MAC=00:01:5c:9d:d6:74;CM-QOS=1.1;CM-VER=3.1;
   09:58:10
Sat Aug 8 2020
 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=00:40:36:61:5f:92;CMTS-MAC=00:01:5c:9d:d6:74;CM-QOS=1.1;CM-VER=3.1;
   09:58:10
Sat Aug 8 2020
 Critical (3) Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=00:40:36:61:5f:92;CMTS-MAC=00:01:5c:9d:d6:74;CM-QOS=1.1;CM-VER=3.1;
   09:58:10
Sat Aug 8 2020
 Critical (3) 16 consecutive T3 timeouts while trying to range on upstream channel 0;CM-MAC=00:40:36:61:5f:92;CMTS-MAC=00:01:5c:9d:d6:74;CM-QOS=1.1;CM-VER=3.1;
   09:58:10
Sat Aug 8 2020
 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=00:40:36:61:5f:92;CMTS-MAC=00:01:5c:9d:d6:74;CM-QOS=1.1;CM-VER=3.1;
   09:58:11
Sat Aug 8 2020
 Critical (3) No Ranging Response received - T3 time-out;CM-MAC=00:40:36:61:5f:92;CMTS-MAC=00:01:5c:9d:d6:74;CM-QOS=1.1;CM-VER=3.1;
   09:58:13
Sat Aug 8 2020
 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=00:40:36:61:5f:92;CMTS-MAC=00:01:5c:9d:d6:74;CM-QOS=1.1;CM-VER=3.1;
   09:58:13
Sat Aug 8 2020
 Critical (3) No Ranging Response received - T3 time-out;CM-MAC=00:40:36:61:5f:92;CMTS-MAC=00:01:5c:9d:d6:74;CM-QOS=1.1;CM-VER=3.1;
   09:58:14
Sat Aug 8 2020
 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=00:40:36:61:5f:92;CMTS-MAC=00:01:5c:9d:d6:74;CM-QOS=1.1;CM-VER=3.1;
   09:58:15
Sat Aug 8 2020
 Critical (3) No Ranging Response received - T3 time-out;CM-MAC=00:40:36:61:5f:92;CMTS-MAC=00:01:5c:9d:d6:74;CM-QOS=1.1;CM-VER=3.1;
   09:58:15
Sat Aug 8 2020
 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=00:40:36:61:5f:92;CMTS-MAC=00:01:5c:9d:d6:74;CM-QOS=1.1;CM-VER=3.1;
   09:58:17
Sat Aug 8 2020
 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=00:40:36:61:5f:92;CMTS-MAC=00:01:5c:9d:d6:74;CM-QOS=1.1;CM-VER=3.1;
   09:58:18
Sat Aug 8 2020
 Critical (3) No Ranging Response received - T3 time-out;CM-MAC=00:40:36:61:5f:92;CMTS-MAC=00:01:5c:9d:d6:74;CM-QOS=1.1;CM-VER=3.1;
   09:58:18
Sat Aug 8 2020
 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=00:40:36:61:5f:92;CMTS-MAC=00:01:5c:9d:d6:74;CM-QOS=1.1;CM-VER=3.1;
   09:58:18
Sat Aug 8 2020
 Critical (3) No Ranging Response received - T3 time-out;CM-MAC=00:40:36:61:5f:92;CMTS-MAC=00:01:5c:9d:d6:74;CM-QOS=1.1;CM-VER=3.1;
   09:58:28
Sat Aug 8 2020
 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=00:40:36:61:5f:92;CMTS-MAC=00:01:5c:9d:d6:74;CM-QOS=1.1;CM-VER=3.1;
   09:58:39
Sat Aug 8 2020
 Critical (3) No Ranging Response received - T3 time-out;CM-MAC=00:40:36:61:5f:92;CMTS-MAC=00:01:5c:9d:d6:74;CM-QOS=1.1;CM-VER=3.1;
   09:59:00
Sat Aug 8 2020
 Critical (3) No Ranging Response received - T3 time-out;CM-MAC=00:40:36:61:5f:92;CMTS-MAC=00:01:5c:9d:d6:74;CM-QOS=1.1;CM-VER=3.1;
   09:59:41
Sat Aug 8 2020
 Critical (3) No Ranging Response received - T3 time-out;CM-MAC=00:40:36:61:5f:92;CMTS-MAC=00:01:5c:9d:d6:74;CM-QOS=1.1;CM-VER=3.1;
   10:00:07
Sat Aug 8 2020
 Critical (3) No Ranging Response received - T3 time-out;CM-MAC=00:40:36:61:5f:92;CMTS-MAC=00:01:5c:9d:d6:74;CM-QOS=1.1;CM-VER=3.1;
   10:02:11
Sat Aug 8 2020
 Critical (3) No Ranging Response received - T3 time-out;CM-MAC=00:40:36:61:5f:92;CMTS-MAC=00:01:5c:9d:d6:74;CM-QOS=1.1;CM-VER=3.1;
   10:02:25
Sat Aug 8 2020
 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=00:40:36:61:5f:92;CMTS-MAC=00:01:5c:9d:d6:74;CM-QOS=1.1;CM-VER=3.1;
   10:02:28
Sat Aug 8 2020
 Critical (3) No Ranging Response received - T3 time-out;CM-MAC=00:40:36:61:5f:92;CMTS-MAC=00:01:5c:9d:d6:74;CM-QOS=1.1;CM-VER=3.1;
   10:02:28
Sat Aug 8 2020
 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=00:40:36:61:5f:92;CMTS-MAC=00:01:5c:9d:d6:74;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=00:40:36:61:5f:92;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
   Time Not Established Notice (6) Honoring MDD; IP provisioning mode = IPv6
   10:05:29
Sat Aug 8 2020
 Notice (6) DS profile assignment change. DS Chan ID: 32; Previous Profile: ; New Profile: 1 2 3.;CM-MAC=00:40:36:61:5f:92;CMTS-MAC=00:01:5c:9d:d6:74;CM-QOS=1.1;CM-VER=3.1;
   10:32:47
Sat Aug 8 2020
 Notice (6) CM-STATUS message sent. Event Type Code: 16; Chan ID: 48; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 3.;CM-MAC=00:40:36:61:5f:92;CMTS-MAC=00:01:5c:9d:d6:74;CM-QOS=1.1;CM-VER=3.1;
   10:33:18
Sat Aug 8 2020
 Notice (6) CM-STATUS message sent. Event Type Code: 24; Chan ID: 48; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 3.;CM-MAC=00:40:36:61:5f:92;CMTS-MAC=00:01:5c:9d:d6:74;CM-QOS=1.1;CM-VER=3.1;
EG
Expert

Re: Intermittent Dropping of Internet

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 !

 



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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.
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denonsix2
Regular Visitor

Re: Intermittent Dropping of Internet

Thank you so much for the help!!

EG
Expert

Re: Intermittent Dropping of Internet

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!
ComcastTambrey
Official Employee

Re: Intermittent Dropping of Internet

Hello, denonsix2!

I'm glad to see you were able to work with EG to narrow down the cause of your intermittent internet connection. I would love to take a closer look into this for you and make sure we get you back to a stable connection you can enjoy. Please send me a private message with your first and last name, as well as your service address so I can assist. 

 

 To send a private message, click my name "ComcastTambrey", then click "send a message".


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!
denonsix2
Regular Visitor

Re: Intermittent Dropping of Internet

ComcastTambrey, did you recieve my PM?

I haven't heard back yet so was just checking in to see if this was still being investigated.

Thanks!

ComcastTambrey
Official Employee

Re: Intermittent Dropping of Internet

Hello, denonsix2! I just wanted to follow up here quickly to let you know I did receive your PM's over my weekend and have replied accordingly. I look forward to your next reply so I can continue working with you!


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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!
Schlosserd
New Poster

Re: Intermittent Dropping of Internet

@ComcastTambrey 

Hello, I am having the same issues but I am using your newest modem.  I have called every week for the past 6 weeks and now am going to have my 3rd tech out again, but cannot get any correction.

 

I apologize for reaching out to you like this, however, when I click your name I am unable to send a message to you.