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SB6121 issues with heavy uploading

Regular Visitor

SB6121 issues with heavy uploading

I recently started using a cloud backup service. The initial upload takes weeks, probably, and originally used the full 6MB upload capacity. I started having problems where the internet connection dropped, which were solved by power cycling the modem. The backup service support person suggested dialing back the program to use 1MB upload, and since then the internet connection has not dropped. As I am supposed to get 6MB, this seems like a problem.

 

The upstream power levels I get are 38–42 dBmV, which is low. (Downstream S/N are 36–37 dB.)

 

The error log shows messages like this:

MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1;CM-MAC=94:cc:b9:d0:42:8d;CMTS-MAC=00:9e:1e:58:cd:d2;CM-QOS=1.1;CM-VER=3.0;

Seems like there is one of these for each power reset message.

 

Suggestions?

 

Regular Contributor

Re: SB6121 issues with heavy uploading

Due to when the 6121 was released it's getting a bit long in the tooth / EOL\EOS potentially as well.

 

If you can login and grab a snapshot of the power/snr levels from the modem admin page that would be helpful to see if there's a potential line issue or a splitter gone wrong.  

Regular Visitor

Re: SB6121 issues with heavy uploading

I think I already provided that information...

 

Official Employee

Re: SB6121 issues with heavy uploading

Hello cbfiddle. I can assist with troubleshooting your upload performance issues. I'd like to start with performing a diagnostics test against your modem. Please send me a private message and include your full name, service address, and account number so I can access your account.



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Expert

Re: SB6121 issues with heavy uploading


cbfiddle wrote:

 

The upstream power levels I get are 38–42 dBmV, which is low.  


FWIW, no they are not low. They are o/k.



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Authorized Vendor

Re: SB6121 issues with heavy uploading

Comcast should be helping you on the RF issues..

 

Upstream Rx Power     
-0.5     0.0     0.0     0.5
Upstream SNR Ch     
34.3     36.5     37.8     37.5

Upstream ICFR     
1.5     1.61     1.68     2.44
Upstream Ripples     
2     4     4     4

Down FEC Corrected     
1.0E-5     1.0E-5     1.0E-5     9.9E-6
Down FEC Uncorrectable     
4.3E-7     4.4E-7     4.6E-7     4.4E-7
Up FEC Corrected     
1.2E-4     1.2E-4     1.2E-4     1.2E-4
Up FEC Uncorrectable     
3.3E-6     3.3E-6     3.3E-6     3.3E-6

-------------------------------------
Network Engineer, IP Engineer, Docsis..; the views expressed on this post are mine and do not necessarily reflect the views of my employer..

Gamer.. Living the dream one catastrophe at a time Smiley Happy ..
Official Employee

Re: SB6121 issues with heavy uploading

I agree @ArrisTuska. I am waiting on the private message to be able to access the account, per our security policy. 



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Regular Visitor

Re: SB6121 issues with heavy uploading

Three days ago, a Comcast tech came out and replaced a cable.

 

The modem worked fine for two days after that, but froze 3 times yesterday. When frozen, even the modem admin page does not respond. I have attached the modem status information.

Official Employee

Re: SB6121 issues with heavy uploading

@cbfiddle, We apologize you are still experiencing issues. Can you please retest today and provide new speed test results? I also responded to your private message. 



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Regular Visitor

Re: SB6121 issues with heavy uploading

I also observe that the hangs almost always occur when I am web browsing (and the cloud backup is uploading). Makes me think there is some sort of conflict between the two activities.

Speed test 82.58 / 6.22, second time 80.78/5.94

 

Channel ID 13  14  15  16 
Frequency 585000000 Hz  591000000 Hz  597000000 Hz  603000000 Hz 
Signal to Noise Ratio 37 dB  37 dB  37 dB  37 dB 
Downstream Modulation QAM256  QAM256  QAM256  QAM256 
Power Level
The Downstream Power Level reading is a snapshot taken at the time this page was requested. Please Reload/Refresh this Page for a new reading
4 dBmV   3 dBmV   4 dBmV   4 dBmV  

 

Upstream Bonding Channel Value
Channel ID
Frequency 35700000 Hz  29200000 Hz  22700000 Hz  16200000 Hz 
Ranging Service ID 13  13  13  13 
Symbol Rate 5.120 Msym/sec  5.120 Msym/sec  5.120 Msym/sec  5.120 Msym/sec 
Power Level 34 dBmV  34 dBmV  32 dBmV  31 dBmV 
Upstream Modulation [2] QPSK
[1] 16QAM
[3] 64QAM
 
[2] QPSK
[1] 16QAM
[3] 64QAM
 
[2] QPSK
[1] 16QAM
[3] 64QAM
 
[2] QPSK
[1] 16QAM
[3] 64QAM
 
Ranging Status Success  Success  Success  Success 

 

Signal Stats (Codewords) Bonding Channel Value
Channel ID 13  14  15  16 
Total Unerrored Codewords 1087678836  1085704669  1085704848  1085704677 
Total Correctable Codewords 31  21  19  16 
Total Uncorrectable Codewords 740  579  548  551 
Official Employee

Re: SB6121 issues with heavy uploading

Hi cbfiddle. I would like to poll out CMTS again for the historical signal plots. Due to our security policy so that I can access your account, please send me a private message and include your full name, service address, and account number so I can assist you. 



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Expert

Re: SB6121 issues with heavy uploading

Old thread being locked.


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