Skip to main content
Question

S34 intermittency - ISP or router issue? Event log shown

  • January 2, 2026
  • 3 replies
  • 63 views
T
The Many
Forum|alt.badge.img

My brand-new S34 modem is disconnecting for 5-10 minutes about twice every hour.  Xfinity already came out, but may need to come back.  Based on the SNR data, and the Event Log entries, can someone tell me if my problem is comms with my router, or Xfinity?  

TIA,

Tom

SNR data (partial, but typical):

Chan    Status    Modul.    Freq.        SigStr.        MER     Corr.Err.    Uncorr. Err.
29    Locked    256QAM    651000000 Hz    -0.7 dBmV    39.0 dB    21    53
30    Locked    256QAM    657000000 Hz    -1.0 dBmV    39.0 dB    42    33
31    Locked    256QAM    663000000 Hz    -1.1 dBmV    39.0 dB    17    54
32    Locked    256QAM    669000000 Hz    -0.5 dBmV    39.0 dB    10    58
37    Locked    OFDM PLC    690000000 Hz    0.4 dBmV    40.0 dB    69596840    1

 

Upstream Bonded Channels
Channel ID    Lock Status    US Channel Type    Frequency    Width    Power
4    Locked    SC-QAM    16400000 Hz    6400000    46.3 dBmV
5    Locked    SC-QAM    39600000 Hz    1600000    46.8 dBmV
3    Locked    SC-QAM    22800000 Hz    6400000    46.3 dBmV
2    Locked    SC-QAM    29200000 Hz    6400000    46.5 dBmV
1    Locked    SC-QAM    35600000 Hz    6400000    46.8 dBmV

 

Event Log:

01/02/2026 14:51:38    Notice    Successful LAN WebGUI login from 68.50.104.62 on 01/02/26 at 2:51 PM

01/02/2026 14:44:54    Notice    CM-STATUS message sent. Event Type Code: 5; Chan ID: 27; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=(Edited private information);CMTS-MAC=00:01:5c:80:74:5e;CM-QOS=1.1;CM-VER=3.1;

01/02/2026 14:44:53    Critical    SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=(Edited private information);CMTS-MAC=00:01:5c:80:74:5e;CM-QOS=1.1;CM-VER=3.1;

01/02/2026 14:44:14    Warning    RNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW;CM-MAC=(Edited private information);CMTS-MAC=00:01:5c:80:74:5e;CM-QOS=1.1;CM-VER=3.1;

01/02/2026 14:43:55    Notice    CM-STATUS message sent. Event Type Code: 5; Chan ID: 4; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=(Edited private information);CMTS-MAC=00:01:5c:80:74:5e;CM-QOS=1.1;CM-VER=3.1;

01/02/2026 14:43:49    Warning    RNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW;CM-MAC=(Edited private information);CMTS-MAC=00:01:5c:80:74:5e;CM-QOS=1.1;CM-VER=3.1;

01/02/2026 14:43:47    Critical    No Ranging Response received - T3 time-out;CM-MAC=(Edited private information);CMTS-MAC=00:01:5c:80:74:5e;CM-QOS=1.1;CM-VER=3.1;

01/02/2026 14:43:02    Warning    RNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW;CM-MAC=(Edited private information);CMTS-MAC=00:01:5c:80:74:5e;CM-QOS=1.1;CM-VER=3.1;

01/02/2026 14:41:40    Warning    RNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW;CM-MAC=(Edited private information);CMTS-MAC=00:01:5c:80:74:5e;CM-QOS=1.1;CM-VER=3.1;

01/02/2026 14:40:03    Warning    RNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW;CM-MAC=(Edited private information);CMTS-MAC=00:01:5c:80:74:5e;CM-QOS=1.1;CM-VER=3.1;

01/02/2026 14:15:16    Warning    RNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW;CM-MAC=(Edited private information);CMTS-MAC=00:01:5c:80:74:5e;CM-QOS=1.1;CM-VER=3.1;

01/02/2026 14:09:40    Warning    RNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW;CM-MAC=(Edited private information);CMTS-MAC=00:01:5c:80:74:5e;CM-QOS=1.1;CM-VER=3.1;

01/02/2026 14:09:38    Warning    MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1

01/02/2026 14:09:04    Critical    No Ranging Response received - T3 time-out;CM-MAC=(Edited private information);CMTS-MAC=00:01:5c:80:74:5e;CM-QOS=1.1;CM-VER=3.1;

01/02/2026 14:08:51    Notice    CMSTATUS:US_Diplexer_Mode_Change: [TLV-9], [5-42MHz].

01/02/2026 14:08:44    Critical    Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=(Edited private information);CMTS-MAC=00:01:5c:80:74:5e;CM-QOS=1.1;CM-VER=3.1;

3 replies

S
Wi-Fi Warriors
Forum|alt.badge.img+42

The errors shown in the event logs can only be resolved by your internet service provider, as they are related to the internet service itself.

Could you please let us know who your internet service provider is and the internet speed plan you are subscribed to?

By connecting the modem directly will help us to isolate the problem that if the internet drops on the Wi-Fi router or with the modem when connected to devices like a computer.

And checking the cable signal levels would be the best course of action as cable signal levels in modems refer to the strength and quality of the signals being received and transmitted between the modem and the Internet Service Provider.

Please find the below link, where you can steps to check the cable signal levels. 

https://arris.my.salesforce-sites.com/consumers/articles/knowledge/S33-Cable-Signal-Levels

 

SURFboard Community Moderator Team
T
The Many
Forum|alt.badge.img
  • TomWeberThe Many
  • Author
  • The Many
  • January 8, 2026

Sorry, I’ve been out of town for a couple of days.  As I said at the beginning, I’m on Xfinity as my ISP.  My plan is 150 Mbps down, 35 Mbps up.

I appreciate the confirmation that, based on the Event Log excerpt I provided, the problem is with Xfinity.

I had also shown a sample of the signal levels, both up- and down-stream.  Is there something additional that you’re requesting that I’m not keyed into?

One probably irrelevant factoid (?!) is that I activated my S34 with Xfinity using their instructions.  But in my Arris app, my modem claims that Cox is my provider. Any chance that there’s some subtle difference in a config file?

Thanks,

Tom

S
Wi-Fi Warriors
Forum|alt.badge.img+42

That’s not the case. For cable modems, you select your service provider during the initial setup, which is what’s reflected in the app. If you need to change the provider, you’ll have to remove the device from the app and then select your preferred provider. After that, you’ll be guided through the modem setup again, where you’ll need to enter the serial number and MAC address. Once completed, the service provider will be displayed under the device information section.

SURFboard Community Moderator Team
Terms & ConditionsCookie settingsAccessibility statement