Visitor

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3 Messages

Wednesday, November 19th, 2025 8:59 PM

Dynamic Range Window violation

Hello,

I have been experiencing random outages that I have traced back to my modem. Upon checking the modem, logs I am seeing these errors, which correlate to other similar complaints. How can I get this resolved?

    13:49:17
Wed Nov 19 2025
  Warning (5)   Dynamic Range Window violation
    14:07:20
Wed Nov 19 2025
  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=3.1;
    14:27:02
Wed Nov 19 2025
  Warning (5)   RNG-RSP CCAP Commanded Power Exceeds Value Corresponding to the Top of the DRW;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;

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Visitor

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3 Messages

2 hours ago

  Startup Step Status Comment

  
   Acquire Downstream Channel 453000000 Hz Locked
  
   Upstream Connection OK Operational
  
   Boot State OK Operational

  
   Configuration File OK
  
   Security Enabled BPI+ Security:
Finally, your cable modem exchanges tokens with your service provider to protect your Internet traffic. It is rare for this step to fail.  

 Downstream Bonded Channels  
  
   Channel Lock Status Modulation Channel ID Freq. (MHz) Pwr (dBmV) SNR (dB) Corrected Uncorrected
   1 Locked QAM256 12 453.0 -3.3 43.9 555 480
   2 Locked QAM256 1 387.0 -3.4 43.8 682 1442
   3 Locked QAM256 2 393.0 -3.2 43.9 731 1391
   4 Locked QAM256 3 399.0 -3.4 43.8 719 746
   5 Locked QAM256 4 405.0 -3.9 43.5 614 1343
   6 Locked QAM256 5 411.0 -3.5 43.6 611 1185
   7 Locked QAM256 6 417.0 -3.4 43.9 507 1111
   8 Locked QAM256 7 423.0 -3.5 43.9 518 762
   9 Locked QAM256 8 429.0 -3.7 43.6 486 797
   10 Locked QAM256 9 435.0 -3.8 43.6 550 788
   11 Locked QAM256 10 441.0 -3.3 43.9 448 1065
   12 Locked QAM256 11 447.0 -3.3 43.9 494 568
   13 Locked QAM256 13 459.0 -3.5 43.9 586 430
   14 Locked QAM256 14 465.0 -3.2 44.1 502 684
   15 Locked QAM256 15 471.0 -2.9 44.2 508 438
   16 Locked QAM256 16 477.0 -3.2 44.1 506 429
   17 Locked QAM256 17 957.0 0.6 44.6 0 0
   18 Locked QAM256 18 963.0 1.1 45.0 0 0
   19 Locked QAM256 19 969.0 1.3 44.9 0 0
   20 Locked QAM256 20 975.0 0.7 44.8 0 0
   21 Locked QAM256 21 981.0 0.9 44.8 0 0
   22 Locked QAM256 22 987.0 0.8 44.9 0 0
   23 Locked QAM256 23 993.0 0.7 44.7 0 0
   24 Locked QAM256 24 999.0 0.4 44.3 8 0
   25 Locked OFDM PLC 193 774.0 0.2 45.3 561392 0

Upstream Bonded Channels  
  
   Channel Lock Status Channel Type Channel ID Symb. Rate (Ksym/sec) Freq. (MHz) Pwr (dBmV)
   1 Locked SC-QAM 1 5120 16.4 57.0
   2 Locked SC-QAM 2 5120 22.8 55.5
   3 Locked SC-QAM 3 5120 29.2 54.3
   4 Locked SC-QAM 4 5120 35.6 52.8

Expert

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114.6K Messages

1 hour ago

The upstream power is too high / out of spec. That can cause random disconnects, spontaneous re-booting of the modem, speed, packet loss, latency problems, the unbonding of channels, and those errors

In an effort to try to obtain better connectivity / more wiggle room, check to see if there are any excess/unneeded coax cable splitters in the line leading to the modem that can be eliminated/reconfigured. Any splitters that remain should be high quality and cable rated for 5-1002 MHz, bi-directional, and no gold colored garbage from Home Depot, Target, Wal-Mart, etc. Splitters should be swapped with known to be good / new ones to test.

Also, check the coax cable for any damage such as cuts, nicks, abrasions, kinks, sharp bends, or animal chews.

If there aren't any unneeded splitters that can be eliminated and if your coax wiring setup can't be reconfigured so that there is a single two-way splitter connected directly off of the drop from the street / pole with one port feeding the modem and the other port feeding the rest of the house/equipment with additional splits as needed and you've checked all the wiring and fittings for integrity and tightness and refresh them by taking them apart then check for and clean off any corrosion / oxidation on the center wire and put them back together again, then perhaps it's best to book a tech visit to investigate and correct.

Visitor

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3 Messages

Thanks for the suggestions. I am limited in the changes I can make in the house, but perhaps I can move to another coax outlet that is closer to the main and at least see the results. 

Expert

 • 

114.6K Messages

1 hour ago

Worth a shot !

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