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Repeated drops

N0_service
Contributor

Repeated drops

My signal keeps dropping intermittently.  How can I resolve?  Thanks

 

Time Not Established

Critical (3)

No Ranging Response received - T3 time-out;CM-MAC=removed;CMTS-MAC=removed;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=removed;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;

Wed May 27 00:34:16 2020

Warning (5)

ToD request sent- No Response received;CM-MAC=removed;CMTS-MAC=removed;CM-QOS=1.1;CM-VER=3.1;

Wed May 27 00:34:12 2020

Critical (3)

Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=removed;CMTS-MAC=removed;CM-QOS=1.1;CM-VER=3.1;

Wed May 27 00:34:12 2020

Critical (3)

SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=removed;CMTS-MAC=removed;CM-QOS=1.1;CM-VER=3.1;

Wed May 27 00:34:11 2020

Critical (3)

Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=removed;CMTS-MAC=removed;CM-QOS=1.1;CM-VER=3.1;

Wed May 27 00:34:11 2020

Critical (3)

SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=removed;CMTS-MAC=removed;CM-QOS=1.1;CM-VER=3.1;

Wed May 27 00:33:58 2020

Error (4)

ToD request sent- No Response received;CM-MAC=removed;CMTS-MAC=removed;CM-QOS=1.1;CM-VER=3.1;

Wed May 27 00:33:58 2020

Critical (3)

SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=removed;CMTS-MAC=removed;CM-QOS=1.1;CM-VER=3.1;

Wed May 27 00:33:33 2020

Critical (3)

Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=removed;CMTS-MAC=removed;CM-QOS=1.1;CM-VER=3.1;

Wed May 27 00:33:32 2020

Critical (3)

SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=removed;CMTS-MAC=removed;CM-QOS=1.1;CM-VER=3.1;

Wed May 27 00:33:26 2020

Error (4)

ToD request sent- No Response received;CM-MAC=removed;CMTS-MAC=removed;CM-QOS=1.1;CM-VER=3.1;

Wed May 27 00:33:26 2020

Critical (3)

SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=removed;CMTS-MAC=removed;CM-QOS=1.1;CM-VER=3.1;

Wed May 27 00:33:23 2020

Critical (3)

Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=removed;CMTS-MAC=removed;CM-QOS=1.1;CM-VER=3.1;

Wed May 27 00:33:22 2020

Critical (3)

SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=removed;CMTS-MAC=removed;CM-QOS=1.1;CM-VER=3.1;

Wed May 27 00:33:10 2020

Error (4)

ToD request sent- No Response received;CM-MAC=removed;CMTS-MAC=removed;CM-QOS=1.1;CM-VER=3.1;

Wed May 27 00:33:09 2020

Critical (3)

SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=removed;CMTS-MAC=removed;CM-QOS=1.1;CM-VER=3.1;

Wed May 27 00:33:02 2020

Error (4)

ToD request sent- No Response received;CM-MAC=removed;CMTS-MAC=removed;CM-QOS=1.1;CM-VER=3.1;

Wed May 27 00:33:01 2020

Critical (3)

SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=removed;CMTS-MAC=removed;CM-QOS=1.1;CM-VER=3.1;

Wed May 27 00:32:57 2020

Error (4)

ToD request sent- No Response received;CM-MAC=removed;CMTS-MAC=removed;CM-QOS=1.1;CM-VER=3.1;

Wed May 27 00:32:57 2020

Critical (3)

SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=removed;CMTS-MAC=removed;CM-QOS=1.1;CM-VER=3.1;

Wed May 27 00:32:55 2020

Error (4)

ToD request sent- No Response received;CM-MAC=removed;CMTS-MAC=removed;CM-QOS=1.1;CM-VER=3.1;

Wed May 27 00:32:54 2020

Critical (3)

SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=removed;CMTS-MAC=removed;CM-QOS=1.1;CM-VER=3.1;

Wed May 27 00:32:54 2020

Error (4)

ToD request sent- No Response received;CM-MAC=removed;CMTS-MAC=removed;CM-QOS=1.1;CM-VER=3.1;

Wed May 27 00:32:54 2020

Critical (3)

SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=removed;CMTS-MAC=removed;CM-QOS=1.1;CM-VER=3.1;

Wed May 27 00:30:34 2020

Warning (5)

MDD message timeout;CM-MAC=removed;CMTS-MAC=removed;CM-QOS=1.1;CM-VER=3.1;

Wed May 27 00:30:33 2020

Critical (3)

SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=removed;CMTS-MAC=removed;CM-QOS=1.1;CM-VER=3.1;

Tue May 26 23:12:09 2020

Notice (6)

CM-STATUS message sent. Event Type Code: 24; Chan ID: 37; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 0 1 2 3.;CM-MAC=removed;CMTS-MAC=removed;CM-QOS=1.1;CM-VER=3.1;

EG
Expert

Re: Repeated drops

Please also post the *Downstream Power Level*, the *Upstream Power Level*, and the *SNR* (Signal to Noise Ratio) numbers.




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N0_service
Contributor

Re: Repeated drops

They look to be in spec (albeit SNR a bit low), which is what's puzzling

 

Downstream Bonded Channels
Channel Lock Status Modulation Channel ID Frequency Power SNR Correctables Uncorrectables
1 Locked QAM256 29 669000000 Hz 5.6 dBmV 37.7 dB 0 0
2 Locked QAM256 6 531000000 Hz 6.9 dBmV 39 dB 0 0
3 Locked QAM256 7 537000000 Hz 7 dBmV 39 dB 0 0
4 Locked QAM256 8 543000000 Hz 6.8 dBmV 38.9 dB 0 0
5 Locked QAM256 9 549000000 Hz 6.6 dBmV 38.9 dB 0 0
6 Locked QAM256 10 555000000 Hz 6.7 dBmV 38.7 dB 0 0
7 Locked QAM256 11 561000000 Hz 6.5 dBmV 38.6 dB 0 0
8 Locked QAM256 12 567000000 Hz 6.5 dBmV 38.5 dB 0 0
9 Locked QAM256 13 573000000 Hz 6.4 dBmV 38.4 dB 0 0
10 Locked QAM256 14 579000000 Hz 6.3 dBmV 38.4 dB 0 0
11 Locked QAM256 15 585000000 Hz 6.4 dBmV 38.4 dB 0 0
12 Locked QAM256 16 591000000 Hz 6.4 dBmV 38.3 dB 1 0
13 Locked QAM256 17 597000000 Hz 6.3 dBmV 38.2 dB 0 0
14 Locked QAM256 18 603000000 Hz 6.4 dBmV 38.2 dB 0 0
15 Locked QAM256 19 609000000 Hz 6.1 dBmV 38.1 dB 1 0
16 Locked QAM256 20 615000000 Hz 6.2 dBmV 38.2 dB 0 0
17 Locked QAM256 21 621000000 Hz 6.3 dBmV 38.2 dB 0 0
18 Locked QAM256 22 627000000 Hz 6.2 dBmV 38.1 dB 0 0
19 Locked QAM256 23 633000000 Hz 6 dBmV 38 dB 0 0
20 Locked QAM256 24 639000000 Hz 5.8 dBmV 37.9 dB 1 0
21 Locked QAM256 25 645000000 Hz 5.9 dBmV 37.9 dB 2 0
22 Locked QAM256 26 651000000 Hz 5.9 dBmV 37.9 dB 1 0
23 Locked QAM256 27 657000000 Hz 5.7 dBmV 37.9 dB 1 0
24 Locked QAM256 28 663000000 Hz 5.7 dBmV 37.7 dB 0 0
25 Locked QAM256 30 675000000 Hz 5.3 dBmV 37.2 dB 1 0
26 Locked QAM256 31 681000000 Hz 5.4 dBmV 37.5 dB 2 0
27 Locked QAM256 32 687000000 Hz 5.4 dBmV 37.4 dB 0 0
28 Locked QAM256 33 693000000 Hz 5.1 dBmV 37.5 dB 1 0
29 Locked QAM256 34 699000000 Hz 5 dBmV 37.3 dB 1 0
30 Locked QAM256 35 705000000 Hz 4.8 dBmV 37.2 dB 0 0
31 Locked QAM256 36 711000000 Hz 4.8 dBmV 37.2 dB 2 0
32 Not Locked Unknown 0 0 Hz 0.0 dBmV 0.0 dB 0 0
 
Upstream Bonded Channels
Channel Lock Status US Channel Type Channel ID Symbol Rate Frequency Power
1 Locked ATDMA 5 5120 Ksym/sec 35800000 Hz 44.3 dBmV
2 Locked ATDMA 6 5120 Ksym/sec 29400000 Hz 45 dBmV
3 Locked ATDMA 7 5120 Ksym/sec 23000000 Hz 44.8 dBmV
4 Locked ATDMA 8 5120 Ksym/sec 16600000 Hz 44.3 dBmV
5 Locked ATDMA 10 1280 Ksym/sec 39800000 Hz 42 dBmV
6 Not Locked Unknown 0 0 Ksym/sec 0 Hz 0.0 dBmV
7 Not Locked Unknown 0 0 Ksym/sec 0 Hz 0.0 dBmV
8 Not Locked Unknown 0 0 Ksym/sec 0 Hz 0.0 dBmV
 
Downstream OFDM Channels
Channel Lock
Status
Modulation /
Profile ID
Channel
ID
Frequency Power SNR /
MER
Active Subcarrier
Number Range
Unerrored
Codewords
Correctable
Codewords
Uncorrectable
Codewords
1 Locked 0 ,1 ,2 ,3 37 762000000 Hz 4.2 dBmV 36.4 dB 1108 ~ 2987 1394193609 1007278709 0
2 Not Locked 0 0 0 Hz 0 dBmV 0.0 dB 0 ~ 4095 0 0 0
 
Upstream OFDMA Channels
Channel Lock Status Modulation / Profile ID Channel ID Frequency Power
1 Not Locked 0 0 0 Hz 0 dBmV
2 Not Locked 0 0 0 Hz 0 dBmV
 
N0_service
Contributor

Re: Repeated drops

EG - I posted the power levels per your request.  Any suggestions?

EG
Expert

Re: Repeated drops

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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ComcastMorgan
Official Employee

Re: Repeated drops

Hi there, N0_service. Sorry to hear about the trouble with your connection. I'd like to help. I can take a look at a few diagnostics on this end. To start, please send me a PM with your first and last name. I will help you out from there. 

 

To send a private message, please click my name "ComcastMorgan" then select "Send a Message" on the right side.


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