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user_ea1685
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Thu, Aug 5, 2021 5:13 PM

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Connection dropping intermittently

Hello,

I've been having an issue for the last week with our internet dropping several times a day, more frequently on some days and less frequently on others. 

We had a service technician come out yesterday and he replaced one of coax connectors he said that was old, and tightened the coax connector that goes from my wall to the modem. 

My modem is a Motorola 24x8 Cable Modem, Model MB7621.


A representative I spoke to today said it was an issue with my modem, and that he is sending me another one. 

Looking at my modem's information, I'm seeing a lot of T3 and T4 errors, along with SYNC Timing Synchronization failure errors. I'm seeing lots of packets corrected and uncorrected, as well as some downstream and upstream channels not receiving any signal at all. 

I'll be waiting for the new modem, and hopefully that resolves it, but maybe someone here could provide some more insight on the numbers I'm seeing. 

Downstream:

   Channel Lock Status Modulation Channel ID Freq. (MHz) Pwr (dBmV) SNR (dB) Corrected Uncorrected
1 Locked QAM256 21 531.0 -1.5 37.3 4198297 1065520
2 Locked QAM256 22 537.0 -1.9 37.2 4994533 1226975
3 Locked QAM256 23 543.0 -1.8 37.5 2451001 382932
4 Locked QAM256 24 549.0 -1.2 37.8 3465189 665147
5 Locked QAM256 25 555.0 -0.3 38.2 3183852 861094
6 Not Locked Unknown 0 561.0 0.0 0.0 996411 661755
7 Locked QAM256 27 567.0 2.2 38.9 141945 288695
8 Locked QAM256 28 573.0 2.6 38.9 2336812 2976891
9 Locked QAM256 29 579.0 1.9 38.6 160164 15252
10 Locked QAM256 30 585.0 0.2 38.1 222135 117575
11 Locked QAM256 31 591.0 -1.1 37.1 253733 226800
12 Locked QAM256 32 597.0 -2.2 37.0 311152 238492
13 Locked QAM256 33 603.0 -2.1 37.3 718574 290147
14 Locked QAM256 34 609.0 -1.2 37.9 724263 431310
15 Not Locked Unknown 0 615.0 0.0 0.0 333065 738040
16 Locked QAM256 36 621.0 2.6 39.3 454115 854118
17 Locked QAM256 37 627.0 4.8 39.9 10368414 8045110
18 Locked QAM256 38 633.0 6.2 40.0 2189518 3118587
19 Locked QAM256 39 639.0 6.9 40.0 4415154 4835672
20 Locked QAM256 40 645.0 5.3 39.9 5047852 5715292
21 Locked QAM256 41 651.0 3.7 39.7 7017879 6529727
22 Not Locked Unknown 0 657.0 0.0 0.0 8514370 8068173
23 Not Locked Unknown 0 663.0 0.0 0.0 10874621 10686703
24 Not Locked Unknown 0 669.0 0.0 0.0 9578662 10030357
Total             82951711 68070364


Upstream:

   Channel Lock Status Channel Type Channel ID Symb. Rate (Ksym/sec) Freq. (MHz) Pwr (dBmV)
1 Locked ATDMA 4 5120 16.4 33.3
2 Locked ATDMA 1 5120 35.6 35.0
3 Locked ATDMA 2 5120 29.2 34.0
4 Locked ATDMA 3 5120 22.8 33.3
5 Locked ATDMA 5 2560 40.4 35.5
6 Not Locked Unknown 0 0 0 0.0
7 Not Locked Unknown 0 0 0 0.0
8 Not Locked Unknown 0 0 0 0.0


Event Log:

Time   Priority   Description 
 Thu Aug 05 10:14:26 2021    Critical (3)   SYNC Timing Synchronization failure - Failed to receive MAC SYNC frame within time-out period;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.0; 
 Thu Aug 05 10:14:48 2021    Warning (5)   MDD message timeout;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.0; 
 Thu Aug 05 10:14:53 2021    Critical (3)   SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.0; 
 Thu Aug 05 10:15:01 2021    Warning (5)   MDD message timeout;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.0; 
 Thu Aug 05 10:15:02 2021    Critical (3)   SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.0; 
 Thu Aug 05 10:15:02 2021    Warning (5)   MDD message timeout;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.0; 
 Thu Aug 05 10:15:05 2021    Critical (3)   SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.0; 
 Thu Aug 05 10:15:45 2021    Warning (5)   MDD message timeout;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.0; 
 Thu Aug 05 10:15:49 2021    Critical (3)   SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.0; 
 Thu Aug 05 10:17:11 2021    Warning (5)   MDD message timeout;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.0; 
 Thu Aug 05 10:17:16 2021    Critical (3)   SYNC Timing Synchronization failure - Failed to receive MAC SYNC frame within time-out period;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.0; 
 Thu Aug 05 10:24:36 2021    Warning (5)   MDD message timeout;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.0; 
 Thu Aug 05 10:24:37 2021    Critical (3)   SYNC Timing Synchronization failure - Failed to receive MAC SYNC frame within time-out period;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.0; 
 Thu Aug 05 10:24:43 2021    Warning (5)   MDD message timeout;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.0; 
 Thu Aug 05 10:24:49 2021    Critical (3)   SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.0; 
 Thu Aug 05 10:30:34 2021    Warning (5)   MDD message timeout;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.0; 
 Thu Aug 05 10:30:35 2021    Critical (3)   SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.0; 
 Thu Aug 05 10:30:45 2021    Warning (5)   MDD message timeout;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.0; 
 Thu Aug 05 10:31:03 2021    Critical (3)   SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.0; 
 Thu Aug 05 10:31:20 2021    Warning (5)   MDD message timeout;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.0; 
 Thu Aug 05 10:31:29 2021    Critical (3)   SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.0; 
 Thu Aug 05 10:31:30 2021    Warning (5)   MDD message timeout;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.0; 
 Thu Aug 05 10:31:33 2021    Critical (3)   SYNC Timing Synchronization failure - Failed to acquire FEC framing;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.0; 
 Thu Aug 05 10:31:55 2021    Critical (3)   Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.0; 
 Thu Aug 05 10:31:56 2021    Critical (3)   SYNC Timing Synchronization failure - Failed to receive MAC SYNC frame within time-out period;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.0; 
 Thu Aug 05 10:47:16 2021    Warning (5)   MDD message timeout;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.0; 
 Thu Aug 05 10:47:31 2021    Critical (3)   SYNC Timing Synchronization failure - Failed to receive MAC SYNC frame within time-out period;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.0; 
 Thu Aug 05 10:49:34 2021    Warning (5)   MDD message timeout;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.0; 
 Thu Aug 05 10:49:35 2021    Critical (3)   Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.0; 
 Thu Aug 05 10:51:18 2021    Warning (5)   MDD message timeout;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.0; 
 Thu Aug 05 10:51:18 2021    Critical (3)   Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.0; 
 Thu Aug 05 10:59:58 2021    Warning (5)   MDD message timeout;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.0; 

Question

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Updated 

7 m ago

 • Edited

435

3

EG

Expert

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95.1K Messages

1 y ago

It looks like you may have some extraneous noise ingressing into the line(s) / forward path somewhere. You may need to get the premises techs involved again. If it is indeed a line impairment, it will still be present no matter what modem is used. Good luck with it and please post back with how things turn out with the new modem.

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user_ea1685

Visitor

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2 Messages

1 y ago

Thank you for the quick response! I'll wait for the new modem to get here and will post my findings once it arrives. If the problem persists I'll escalate it up so another technician can come out to look again. 

0

jbottels

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1 Message

7 m ago

I am literally experiencing the same issue and the same errors.  Did the new model fix the problem??

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0

EG

Expert

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95.1K Messages

@jbottels

Please create a new topic of your own here on this board detailing your issue. Thanks. The original poster has not returned. 5-month-old dead thread now being closed. 

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.

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7 m ago

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