BobDoo's profile

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Friday, April 11th, 2025 7:32 PM

Internet keeps disconnecting - Arris Surfboard S33 DOCSIS 3.1 modem

I recently upgraded from a DOCSIS 3.0 to a 3.1 modem - the Arris Surfboard S33.

My previous service was rock-solid but now I am experiencing disconnects every ~20 minutes, lasting around 4 seconds each.

I'm attaching some logs that might help diagnose my issue based on similar posts I've seen in the past. Please let me know if more information would be helpful.

Connection Status:

*Downstream Bonded Channels*
*Channel ID*    *Lock Status*   *Modulation*    *Frequency*     *Power* *SNR/MER*       *Corrected*     *Uncorrectables*
44              Locked          QAM256          675000000 Hz    -1 dBmV 42 dB           0               0
13              Locked          QAM256          489000000 Hz    1 dBmV  43 dB           0               0
14              Locked          QAM256          495000000 Hz    0 dBmV  44 dB           0               0
15              Locked          QAM256          501000000 Hz    0 dBmV  43 dB           0               0
16              Locked          QAM256          507000000 Hz    -2 dBmV 42 dB           0               0
17              Locked          QAM256          513000000 Hz    -4 dBmV 41 dB           1               0
18              Locked          QAM256          519000000 Hz    -3 dBmV 41 dB           0               0
19              Locked          QAM256          525000000 Hz    -1 dBmV 41 dB           0               0
20              Locked          QAM256          531000000 Hz    0 dBmV  41 dB           0               0
21              Locked          QAM256          537000000 Hz    0 dBmV  40 dB           0               0
22              Locked          QAM256          543000000 Hz    0 dBmV  41 dB           0               0
23              Locked          QAM256          549000000 Hz    0 dBmV  43 dB           0               0
24              Locked          QAM256          555000000 Hz    0 dBmV  43 dB           0               0
25              Locked          QAM256          561000000 Hz    -1 dBmV 43 dB           0               0
26              Locked          QAM256          567000000 Hz    0 dBmV  42 dB           0               0
27              Locked          QAM256          573000000 Hz    0 dBmV  42 dB           0               0
28              Locked          QAM256          579000000 Hz    0 dBmV  43 dB           0               0
29              Locked          QAM256          585000000 Hz    0 dBmV  43 dB           0               0
30              Locked          QAM256          591000000 Hz    0 dBmV  43 dB           0               0
31              Locked          QAM256          597000000 Hz    0 dBmV  43 dB           0               0
32              Locked          QAM256          603000000 Hz    0 dBmV  34 dB           0               0
33              Locked          QAM256          609000000 Hz    0 dBmV  38 dB           0               0
34              Locked          QAM256          615000000 Hz    0 dBmV  43 dB           0               0
35              Locked          QAM256          621000000 Hz    0 dBmV  43 dB           0               0
36              Locked          QAM256          627000000 Hz    0 dBmV  42 dB           0               0
37              Locked          QAM256          633000000 Hz    1 dBmV  42 dB           0               0
38              Locked          QAM256          639000000 Hz    0 dBmV  43 dB           0               0
39              Locked          QAM256          645000000 Hz    0 dBmV  43 dB           0               0
40              Locked          QAM256          651000000 Hz    0 dBmV  44 dB           0               0
41              Locked          QAM256          657000000 Hz    0 dBmV  43 dB           0               0
42              Locked          QAM256          663000000 Hz    0 dBmV  43 dB           0               0
43              Locked          QAM256          669000000 Hz    0 dBmV  43 dB           0               0
193             Locked          OFDM PLC        957000000 Hz    -8 dBmV 39 dB           10729975        0

*Upstream Bonded Channels*
*Channel ID*    *Lock Status*   *US Channel Type*       *Frequency*     *Width* *Power*
1               Locked          SC-QAM                  16400000 Hz     6400000 41.8 dBmV
2               Locked          SC-QAM                  22800000 Hz     6400000 42.3 dBmV
3               Locked          SC-QAM                  29200000 Hz     6400000 42.3 dBmV
4               Locked          SC-QAM                  35600000 Hz     6400000 42.5 dBmV

Sample event log (disconnects appear to relate to the "UCD invalid or channel unusable" messages):

11/4/2025
10:53:15 6 CM-STATUS message sent. Event Type Code: 20; Chan ID: 193; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=xx:xx:xx:xx:xx:xx;CMTS-MAC=yy:yy:yy:yy:yy:yy;CM-QOS=1.1;CM-VER=3.1;
11/4/2025
10:53:15 6 CM-STATUS message sent. Event Type Code: 16; Chan ID: 193; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 0 1 2 3.;CM-MAC=xx:xx:xx:xx:xx:xx;CMTS-MAC=yy:yy:yy:yy:yy:yy;CM-QOS=1.1;CM-VER=3.1;
11/4/2025
10:53:16 5 MDD message timeout;CM-MAC=xx:xx:xx:xx:xx:xx;CMTS-MAC=yy:yy:yy:yy:yy:yy;CM-QOS=1.1;CM-VER=3.1;
11/4/2025
10:53:40 6 CM-STATUS message sent. Event Type Code: 1; Chan ID: 193; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=xx:xx:xx:xx:xx:xx;CMTS-MAC=yy:yy:yy:yy:yy:yy;CM-QOS=1.1;CM-VER=3.1;
11/4/2025
10:54:41 6 CM-STATUS message sent. Event Type Code: 23; Chan ID: 193; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=xx:xx:xx:xx:xx:xx;CMTS-MAC=yy:yy:yy:yy:yy:yy;CM-QOS=1.1;CM-VER=3.1;
11/4/2025
10:59:30 6 CM-STATUS message sent. Event Type Code: 21; Chan ID: 193; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=xx:xx:xx:xx:xx:xx;CMTS-MAC=yy:yy:yy:yy:yy:yy;CM-QOS=1.1;CM-VER=3.1;
11/4/2025
11:13:16 6 DS profile assignment change. DS Chan ID: 32; Previous Profile: ; New Profile: 1 2 3.;CM-MAC=xx:xx:xx:xx:xx:xx;CMTS-MAC=yy:yy:yy:yy:yy:yy;CM-QOS=1.1;CM-VER=3.1;
11/4/2025
11:13:16 3 UCD invalid or channel unusable;CM-MAC=xx:xx:xx:xx:xx:xx;CMTS-MAC=yy:yy:yy:yy:yy:yy;CM-QOS=1.1;CM-VER=3.1;
11/4/2025
11:13:19 6 CM-STATUS message sent. Event Type Code: 21; Chan ID: 193; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=xx:xx:xx:xx:xx:xx;CMTS-MAC=yy:yy:yy:yy:yy:yy;CM-QOS=1.1;CM-VER=3.1;
11/4/2025
11:13:24 5 MDD message timeout;CM-MAC=xx:xx:xx:xx:xx:xx;CMTS-MAC=yy:yy:yy:yy:yy:yy;CM-QOS=1.1;CM-VER=3.1;
11/4/2025
11:13:38 6 CM-STATUS message sent. Event Type Code: 1; Chan ID: 193; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=xx:xx:xx:xx:xx:xx;CMTS-MAC=yy:yy:yy:yy:yy:yy;CM-QOS=1.1;CM-VER=3.1;


New Poster

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4 Messages

4 days ago

Actually, things have gotten much worse, with many correctable and uncorrectable errors on all channels, and more disconnects.

Official Employee

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1.6K Messages

Hello there! Sorry to hear you are still experiencing these concerns.  May I please ask that you send us a direct message with your full name and service address to get started? 

  • Make sure you are signed in here in the Xfinity Forum. Click "Sign In" if necessary
  • Click the "Direct Message" icon (square chat icon in the upper right corner of your screen next to the bell icon)
  • Click the "New message" (pencil and paper) icon
  • Type "Xfinity Support" in the "To:" line and select "Xfinity Support" from the drop-down list which appears. The "Xfinity Support" graphic replaces the "To:" line
  • Type your message in the text area near the bottom of the window
  • Press Enter to send it

[Edit: added direct message instructions]

(edited)

I am an Official Xfinity Employee.
Official Employees are from multiple teams within Xfinity: CARE, Product, Leadership.
We ask that you post publicly so people with similar questions may benefit from the conversation.
Was your question answered? Please, mark a reply as the Accepted Answer.tick

Expert

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109.8K Messages

3 days ago

@BobDoo @XfinityEva 

Please circle back here and post any possible solutions for the issue here in these open public forums so that all readers here may benefit from the exchange / info. This is in keeping with the spirit for which these public help forums were originally intended. Thank you.

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