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MB8600 - HUGE # OFDM corrected errors and high # of uncorrected errors in log for other channels

bdm1955
Frequent Visitor

MB8600 - HUGE # OFDM corrected errors and high # of uncorrected errors in log for other channels

Have a Moto MB8600 and consistantly see a huge # of OFDM errors.  There is only one cable connector between the ingress and the wall outlet.  The connector and wall plate were wired by Xfinity.  So, NO SPLITTERS between ingress and wall plate.  Uptime = 6 days as of this log:

 

Startup Sequence
 

 

  
   Startup StepStatusComment
 

 



  
   Acquire Downstream Channel621000000 HzLocked
 

 


  
   Upstream ConnectionOKOperational
 

 


  
   Boot StateOKOperational
 

 



  
   Configuration FileOK 
 

 


  
   SecurityEnabledBPI+
 

 


  



   Connection Status
 

 

  
   System Up Time6 days 00h:15m:29s 
 

 


  
   Network AccessAllowed 
 

 


 

Downstream Bonded Channels
 

 

 
 

 


  
   ChannelLock StatusModulationChannel IDFreq. (MHz)Pwr (dBmV)SNR (dB)CorrectedUncorrected
   1LockedQAM25630621.00.840.31320
   2LockedQAM25610501.01.841.22323
   3LockedQAM25611507.01.841.3198953
   4LockedQAM25612513.01.741.2179965
   5LockedQAM25613519.01.641.1196946
   6LockedQAM25614525.01.441.2197952
   7LockedQAM25615531.01.240.9224933
   8LockedQAM25616537.01.441.0214940
   9LockedQAM25617543.01.340.7207943
   10LockedQAM25618555.01.040.6212937
   11LockedQAM25619561.01.240.7213931
   12LockedQAM25620567.01.140.6218941
   13LockedQAM25621573.00.940.5203947
   14LockedQAM25622579.01.140.6207943
   15LockedQAM25623585.00.740.3216935
   16LockedQAM25624591.00.940.5202946
   17LockedOFDM PLC25693.00.838.8-135320280518
   18LockedQAM25626597.00.840.3215994
   19LockedQAM25627603.00.640.1191966
   20LockedQAM25628609.00.540.3181979
   21LockedQAM25629615.00.740.3196962
   22LockedQAM25631627.00.740.4215941
   23LockedQAM25632633.00.940.5195962
   24LockedQAM25633639.00.740.4201965
   25LockedQAM25634645.00.840.4238943
   26LockedQAM25635651.00.640.1202955
   27LockedQAM25636657.00.840.52101010
   28LockedQAM25637663.00.640.62171004
   29LockedQAM25638669.00.640.4218996
   30LockedQAM25639675.00.539.82421011
   31LockedQAM25640681.00.340.42201033
   32LockedQAM25641687.00.340.32271029
EG
Expert

Re: MB8600 - HUGE # OFDM corrected errors and high # of uncorrected errors in log for other channels

FWIW, there is a known glitch with some makes / models of modem's firmware where the measuring mechanism incorrectly reads the power level, the SNR, and the bit errors for that channel. So it reads many errors when there really aren't.

 

The bit errors are really pretty low on the QAM256 channels.

 

Are you actually experiencing any connectivity problems ? The downstream stats are good. Please also post the upstream power level figures.



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bdm1955
Frequent Visitor

Re: MB8600 - HUGE # OFDM corrected errors and high # of uncorrected errors in log for other channels

I'd characterize it as choppy.  Have the MB8600 attached to a RAX45 with TV using ethernet from RAX45 to TV.  Picture freezes or drops xFinity altogether - intermittant problems with both 2.4 & 5Ghz wireless (2 AX devices among N & AC devices).  On the laptops/desktops/Samsung S10+ (AX device), Surface Laptop3 (AX device) web pages won't load and then after another try or two, they do render.

 

MB8600 & RAX45 both rebooted 6 days ago (after power was restored to my home) so both devices should have the latest firmware versions.

 

 

EG
Expert

Re: MB8600 - HUGE # OFDM corrected errors and high # of uncorrected errors in log for other channels

Upstream power ?



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bdm1955
Frequent Visitor

Re: MB8600 - HUGE # OFDM corrected errors and high # of uncorrected errors in log for other channels

Upstream seems OK.

 

 Upstream Bonded Channels
 

 

 
 

 


  
   ChannelLock StatusChannel TypeChannel IDSymb. Rate (Ksym/sec)Freq. (MHz)Pwr (dBmV)
   1LockedSC-QAM41512036.545.0
   2LockedSC-QAM42512030.145.3
   3LockedSC-QAM43512023.745.3
   4LockedSC-QAM44512017.345.0
EG
Expert

Re: MB8600 - HUGE # OFDM corrected errors and high # of uncorrected errors in log for other channels

It's good. Are there any error / event log entries ? If so, please post them as well.



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bdm1955
Frequent Visitor

Re: MB8600 - HUGE # OFDM corrected errors and high # of uncorrected errors in log for other channels

No, the logs don't show any Upstream events/errors - no category for them at all.

bdm1955
Frequent Visitor

Re: MB8600 - HUGE # OFDM corrected errors and high # of uncorrected errors in log for other channels

I misspoke.  The Connection status screen does not.  Below is the current Event Log.  A number of these are OFDM related.  (I removed the "MAC" data from the records):

 

Log                                   

 

              Time                    Priority               Description

              06:14:26

Sat Aug 8 2020               Critical (3)                       SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;

              06:14:27

Sat Aug 8 2020               Critical (3)                       Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;

              06:14:51

Sat Aug 8 2020               Critical (3)                       SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;

              06:14:52

Sat Aug 8 2020               Critical (3)                       Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;

              06:15:20

Sat Aug 8 2020               Critical (3)                       SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;

              06:15:21

Sat Aug 8 2020               Critical (3)                       Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;

              06:19:19

Sat Aug 8 2020               Critical (3)                       SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;

              09:23:14

Sat Aug 8 2020               Notice (6)                        Honoring MDD; IP provisioning mode = IPv6

              09:23:01

Sat Aug 8 2020               Notice (6)                        DS profile assignment change. DS Chan ID: 32; Previous Profile: ; New Profile: 1 2 3.;

              08:24:42

Tue Aug 11 2020                          Critical (3)                       Started Unicast Maintenance Ranging - No Response received - T3 time-out;

              15:19:57

Tue Aug 11 2020                          Notice (6)                        CM-STATUS message sent. Event Type Code: 16; Chan ID: 25; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 2.;

              15:20:22

Tue Aug 11 2020                          Notice (6)                        CM-STATUS message sent. Event Type Code: 24; Chan ID: 25; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 2.;

              15:22:45

Tue Aug 11 2020                          Critical (3)                       Started Unicast Maintenance Ranging - No Response received - T3 time-out;

              15:29:37

Tue Aug 11 2020                          Notice (6)                        CM-STATUS message sent. Event Type Code: 16; Chan ID: 25; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 3.;

              15:30:10

Tue Aug 11 2020                          Notice (6)                        CM-STATUS message sent. Event Type Code: 24; Chan ID: 25; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 2 3.;

              19:16:32

Tue Aug 11 2020                          Critical (3)                       Started Unicast Maintenance Ranging - No Response received - T3 time-out;

              23:16:41

Tue Aug 11 2020                          Notice (6)                        CM-STATUS message sent. Event Type Code: 20; Chan ID: 25; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;

              23:16:42

Tue Aug 11 2020                          Notice (6)                        CM-STATUS message sent. Event Type Code: 23; Chan ID: 25; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;

              23:16:43

Tue Aug 11 2020                          Notice (6)                        CM-STATUS message sent. Event Type Code: 22; Chan ID: 25; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;

              23:16:49

Tue Aug 11 2020                          Notice (6)                        CM-STATUS message sent. Event Type Code: 24; Chan ID: 25; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 0 1 2 3.;

              06:12:08

Wed Aug 12 2020                         Critical (3)                       Started Unicast Maintenance Ranging - No Response received - T3 time-out;

              08:19:24

Wed Aug 12 2020                         Notice (6)                        CM-STATUS message sent. Event Type Code: 16; Chan ID: 25; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 3.;

              08:19:49

Wed Aug 12 2020                         Notice (6)                        CM-STATUS message sent. Event Type Code: 24; Chan ID: 25; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 0 1 2 3.;

              09:36:58

Wed Aug 12 2020                         Notice (6)                        CM-STATUS message sent. Event Type Code: 16; Chan ID: 25; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 3.;

              09:37:27

Wed Aug 12 2020                         Notice (6)                        CM-STATUS message sent. Event Type Code: 24; Chan ID: 25; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 0 1 2 3.;

              09:37:54

Wed Aug 12 2020                         Notice (6)                        CM-STATUS message sent. Event Type Code: 16; Chan ID: 25; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 3.;

              09:38:18

Wed Aug 12 2020                         Notice (6)                        CM-STATUS message sent. Event Type Code: 24; Chan ID: 25; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 0 1 2 3.;

              10:28:42

Wed Aug 12 2020                         Critical (3)                       Started Unicast Maintenance Ranging - No Response received - T3 time-out;

              23:18:58

Wed Aug 12 2020                         Notice (6)                        CM-STATUS message sent. Event Type Code: 23; Chan ID: 25; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;

              23:18:59

Wed Aug 12 2020                         Notice (6)                        CM-STATUS message sent. Event Type Code: 22; Chan ID: 25; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;

              23:19:01

Wed Aug 12 2020                         Notice (6)                        CM-STATUS message sent. Event Type Code: 24; Chan ID: 25; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 0 1 2 3.;

              11:07:14

Thu Aug 13 2020                          Critical (3)                       Started Unicast Maintenance Ranging - No Response received - T3 time-out;

EG
Expert

Re: MB8600 - HUGE # OFDM corrected errors and high # of uncorrected errors in log for other channels

Yeah. There is not a "category" only for upstream events. The logging feature logs all general RF errors / events.

 

The signal stats are o/k but the error log entries indicate 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 will be able to poll the CMTS to see whether or not everything is in the green zone, see your node / cable plant and modem health, and also see a history plot for the modem. You should get a reply here in your topic. Good luck !

 

 



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bdm1955
Frequent Visitor

Re: MB8600 - HUGE # OFDM corrected errors and high # of uncorrected errors in log for other channels

Great!  Thank you.

 

EG
Expert

Re: MB8600 - HUGE # OFDM corrected errors and high # of uncorrected errors in log for other channels

Quite welcome !



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ComcastAmir
Official Employee

Re: MB8600 - HUGE # OFDM corrected errors and high # of uncorrected errors in log for other channels

Hi bdm1955, I'd be happy to check your signal levels to help pinpoint where this issue could be coming from so that we can get it resolved. To get started could you please send me a private message with your full name and account number by clicking on my name (ComcastAmir) and then click "Send a message"?


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wiley2
Regular Visitor

Re: MB8600 - HUGE # OFDM corrected errors and high # of uncorrected errors in log for other channels

@bdm1955 I'm having the same issue - any chance you could post an update on what the support rep found?

ndiesslin
New Poster

Re: MB8600 - HUGE # OFDM corrected errors and high # of uncorrected errors in log for other channels

I'm having this exact same issue as well!

EG
Expert

Re: MB8600 - HUGE # OFDM corrected errors and high # of uncorrected errors in log for other channels

@ndiesslin 

 

Please create a new topic of your own here on this board detailing your issue. Thanks. 4 month old dead now being closed.



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