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New MB8600 and Intermittent Problems

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New MB8600 and Intermittent Problems

 

Hello,

 

A week ago I installed an MB8600 since I could no longer get my T-mobile Cellspot to work with my old SB6190 (works with MB6800) and there had been some issues with this combination in the past.  The MB8600 was fine for a couple of days and then a large part of the county lost Comcast internet service for about 12 hours.  Ever since I have been having problems with the internet.  It may be fine for half a day, 10 to 11 MS ping is normal and download speed of 170 to 180 MBS is normal.  But then, often in the afternoon and at night,  the speed will drop to .06 to .25 MBS down load speed.  According to the SpeedTest app I am using there is a burst of data downloaded in the first 1 or 2 seconds of the test and then it goes to zero.  The upload speeds are similarly affected.  The test data seems to agree with what I see if I try to open a web page.  The page will open if it is very basic, anything that takes longer than a second or two to open fails.  Obviously no streams apps work when I am having this problem.

 

The modem indicates that it is operating as a DOCSIS 3.1 modem and I see no change in signal strength or in errors when the problem is occurring.  At the end of this message  is a sample of the signal strength from the modem.  It has been up for about four hours since the last reset by Comcast.  The reset never helps.  I do get a lot of corrected errors on the OFDM PLC channel, over a million an hour, but apparently this is somewhat normal with this modem and the 8600-18.2.12 firmware.

 

 

The event log looks pretty much the same after every reset.  The last two CM-Status messaged may repeat. This has been going on for several days now.  Comcast now has a tech scheduled to come to the house on Sunday.  They replaced all of the outside cables about a year ago and I had almost no problems with the internet for the last year.  I had to reset the 6190 once in that time.  I have no splitters in the cable.  The Comcast cable comes straight into the house and connects to the modem.  The connections inside and directly outside of the house are tight.

 

Does anyone have any suggestions for me to pass along to the tech?  I am sure someone at Comcast is aware of issues and solutions with the MB6800 but I suspect the local tech may not be.

This has already taken hours of my time and is causing problems for my kids who need the internet for school, plus I need it for work.  Cell coverage is terrible here which is what started all of this when I switched modems trying to get the cellspot to work again.

 

 

  15:48:35
Thu Apr 25 2019
  Critical (3)   Resetting the cable modem due to docsDevResetNow
    Time Not Established   Critical (3)   SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=00:40:36:4f:2f:c8;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=00:40:36:4f:2f:c8;CMTS-MAC=00:01:5c:7d:4e:4d;CM-QOS=1.1;CM-VER=3.1;
    Time Not Established   Notice (6)   Honoring MDD; IP provisioning mode = IPv6
    15:49:44
Thu Apr 25 2019
  Notice (6)   DS profile assignment change. DS Chan ID: 32; Previous Profile: ; New Profile: 1.;CM-MAC=00:40:36:4f:2f:c8;CMTS-MAC=00:01:5c:7d:4e:4d;CM-QOS=1.1;CM-VER=3.1;
    17:32:14
Thu Apr 25 2019
  Notice (6)   CM-STATUS message sent. Event Type Code: 16; Chan ID: 33; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 1.;CM-MAC=00:40:36:4f:2f:c8;CMTS-MAC=00:01:5c:7d:4e:4d;CM-QOS=1.1;CM-VER=3.1;
    17:32:40
Thu Apr 25 2019
  Notice (6)   CM-STATUS message sent. Event Type Code: 24; Chan ID: 33; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 1.;CM-MAC=00:40:36:4f:2f:c8;CMTS-MAC=00:01:5c:7d:4e:4d;CM-QOS=1.1;CM-VER=3.1;

 

Channel Lock Status Modulation Channel ID Freq. (MHz) Pwr (dBmV) SNR (d Corrected Uncorrected
   1 Locked QAM256 32 657.0 6.2 40.8 0 0
   2 Locked QAM256 1 465.0 7.2 41.8 0 0
   3 Locked QAM256 2 471.0 7.1 41.6 0 0
   4 Locked QAM256 3 477.0 7.2 41.8 0 0
   5 Locked QAM256 4 483.0 7.3 41.9 0 0
   6 Locked QAM256 5 489.0 7.3 41.9 0 0
   7 Locked QAM256 6 495.0 7.4 42.0 0 0
   8 Locked QAM256 7 501.0 7.3 41.8 0 0
   9 Locked QAM256 8 507.0 7.2 41.5 1 0
   10 Locked QAM256 9 513.0 7.2 41.5 1 0
   11 Locked QAM256 10 519.0 7.1 41.6 3 0

 

 

 

Channel Lock Status Channel Type Channel ID Symb. Rate (Ksym/sec) Freq. (MHz) Pwr (dBmV)
   1 Locked SC-QAM 57 5120 35.6 35.0
   2 Locked SC-QAM 58 5120 29.2 34.0
   3 Locked SC-QAM 59 5120 22.8 33.0
   4 Locked SC-QAM 60 5120 16.0 32.0