longwood8's profile

Visitor

 • 

4 Messages

Thursday, October 3rd, 2024 4:26 PM

Internet keeps disconnecting the last week - UCD invalid or channel unusable - Started Unicast Maintenance Ranging - No Response received

For the last several weeks my internet will disconnect intermittently.   Yes I have restarted my router and modem.  Errors that are appearing frequently in my router logs include: 

Started Unicast Maintenance Ranging - No Response received

UCD invalid or channel unusable

This has been going on for several weeks but is getting worse and worse. 

Expert

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106.9K Messages

1 month ago

Please post all of those error log entries. Copy and paste them, (don't post a screenshot) but redact the CM MAC and the CMTS MAC addresses for your privacy. They are considered to be personal information. The posting of personally identifying information is a violation of their forum guidelines. The forum bot will not allow your post to be seen publicly.

Please also copy all of the text in its entirety of the *Downstream Power Levels*, the *SNR's* (Signal to Noise Ratios), and the *Upstream Power Level* numbers and paste them into your next post.

Visitor

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4 Messages

   09:03:35
Sun Aug 4 2024
  Critical (3)   UCD invalid or channel unusable;
    09:03:35
Sun Aug 4 2024
  Critical (3)   No Ranging Response received - T3 time-out;
    09:03:38
Sun Aug 4 2024
  Critical (3)   UCD invalid or channel unusable;
    09:03:38
Sun Aug 4 2024
  Critical (3)   No Ranging Response received - T3 time-out;C
    09:03:39
Sun Aug 4 2024
  Critical (3)   UCD invalid or channel unusable;
    09:03:40
Sun Aug 4 2024
  Critical (3)   No Ranging Response received - T3 time-out;
    09:03:40
Sun Aug 4 2024
  Critical (3)   UCD invalid or channel unusable;CM
    09:03:40
Sun Aug 4 2024
  Critical (3)   No Ranging Response received - T3 time-out;
    09:03:43
Sun Aug 4 2024
  Critical (3)   UCD invalid or channel unusable;
    09:03:52
Sun Aug 4 2024
  Critical (3)   SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;
    09:03:53
Sun Aug 4 2024
  Critical (3)   No Maintenance Broadcasts for Ranging opportunities received - T2 time-out;
    09:03:55
Sun Aug 4 2024
  Critical (3)   SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;
    09:04:02
Sun Aug 4 2024
  Critical (3)   UCD invalid or channel unusable;CM-MAC=[Edited: "Personal Information"];
    09:04:03
Sun Aug 4 2024
  Critical (3)   No Ranging Response received - T3 time-out;
    09:04:03
Sun Aug 4 2024
  Critical (3)   UCD invalid or channel unusable;
    09:04:04
Sun Aug 4 2024
  Critical (3)   No Ranging Response received - T3 time-out;
    09:04:04
Sun Aug 4 2024
  Critical (3)   UCD invalid or channel unusable;
    09:04:04
Sun Aug 4 2024
  Critical (3)   No Ranging Response received - T3 time-out;
    09:04:06
Sun Aug 4 2024
  Critical (3)   UCD invalid or channel unusable;
    09:04:06
Sun Aug 4 2024
  Critical (3)   No Ranging Response received - T3 time-out;
    09:04:10
Sun Aug 4 2024
  Critical (3)   UCD invalid or channel unusable;
    09:04:11
Sun Aug 4 2024
  Critical (3)   No Ranging Response received - T3 time-out;
    09:05:01
Sun Aug 4 2024
  Critical (3)   UCD invalid or channel unusable;
    09:06:42
Sun Aug 4 2024
  Critical (3)   Started Unicast Maintenance Ranging - No Response received - T3 time-out
    Time Not Established   Critical (3)   SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;
    Time Not Established   Critical (3)   UCD invalid or channel unusable;
    Time Not Established   Notice (6)   Honoring MDD; IP provisioning mode = IPv6
    09:43:25
Thu Oct 3 2024
  Notice (6)   DS profile assignment change. DS Chan ID: 32; Previous Profile: ; New Profile: 1 2 3.
    09:43:26
Thu Oct 3 2024
  Notice (6)   DS profile assignment change. DS Chan ID: 33; Previous Profile: ; New Profile: 1 2 3.;
    09:43:33
Thu Oct 3 2024
  Critical (3)   UCD invalid or channel unusable;
    11:46:34
Thu Oct 3 2024
  Notice (6)   CM-STATUS message sent. Event Type Code: 16; Chan ID: 193; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 3.;
    11:49:37
Thu Oct 3 2024
  Notice (6)   CM-STATUS message sent. Event Type Code: 24; Chan ID: 193; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 3.;

(edited)

Visitor

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4 Messages



   Downstream Bonded Channels  
  
   Channel Lock Status Modulation Channel ID Freq. (MHz) Pwr (dBmV) SNR (dB) Corrected Uncorrected
   1 Locked QAM256 28 555.0 -5.4 41.3 0 0
   2 Locked QAM256 1 393.0 -5.6 41.4 0 0
   3 Locked QAM256 2 399.0 -5.5 41.4 0 0
   4 Locked QAM256 3 405.0 -5.7 41.3 0 0
   5 Locked QAM256 4 411.0 -5.8 41.1 0 0
   6 Locked QAM256 5 417.0 -5.8 41.2 0 0
   7 Locked QAM256 6 423.0 -5.8 41.3 0 0
   8 Locked QAM256 7 429.0 -5.6 41.5 0 0
   9 Locked QAM256 8 435.0 -5.7 41.5 0 0
   10 Locked QAM256 9 441.0 -5.7 41.5 0 0
   11 Locked QAM256 10 447.0 -5.5 41.4 0 0
   12 Locked QAM256 11 453.0 -5.5 41.5 0 0
   13 Locked QAM256 12 459.0 -5.4 41.5 0 0
   14 Locked QAM256 13 465.0 -5.4 41.5 0 0
   15 Locked QAM256 14 471.0 -5.5 41.5 0 0
   16 Locked QAM256 15 477.0 -5.4 41.5 0 0
   17 Locked QAM256 16 483.0 -5.4 41.6 0 0
   18 Locked QAM256 17 489.0 -5.3 41.6 0 0
   19 Locked QAM256 18 495.0 -5.4 41.5 0 0
   20 Locked QAM256 19 501.0 -5.6 41.4 0 0
   21 Locked QAM256 20 507.0 -5.7 41.4 0 0
   22 Locked QAM256 21 513.0 -5.6 41.4 0 0
   23 Locked QAM256 22 519.0 -5.3 41.5 0 0
   24 Locked QAM256 23 525.0 -5.3 41.5 0 0
   25 Locked QAM256 24 531.0 -5.2 41.5 0 0
   26 Locked QAM256 25 537.0 -5.4 41.4 0 0
   27 Locked QAM256 26 543.0 -5.4 41.4 0 0
   28 Locked QAM256 27 549.0 -5.3 41.4 0 0
   29 Locked QAM256 29 561.0 -5.3 41.3 0 0
   30 Locked QAM256 30 567.0 -5.4 41.3 0 0
   31 Locked QAM256 31 573.0 -5.1 41.4 0 0
   32 Locked QAM256 32 579.0 -5.0 41.6 0 0
   33 Locked OFDM PLC 193 690.0 -5.2 41.2 36099240 0
   34 Locked OFDM PLC 194 957.0 -9.0 39.4 35817782 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 51.5
   2 Locked SC-QAM 2 5120 22.8 52.3
   3 Locked SC-QAM 3 5120 29.2 53.0
   4 Locked SC-QAM 4 5120 35.6 54.0



   Downstream Frequency Setting    

Official Employee

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1.3K Messages

Hey @longwood8, Thank you for visiting our official Xfinity Forums Community support page. We greatly appreciate you taking the time to share your experience regarding the Xfinity Internet connectivity issues. I would be more than happy to offer my assistance looking into this further for you.

 

The signals levels appear to be within specification from my review. With the intermittent connectivity, we would want to look at some smaller details within the home. Would you be able to ensure that all coax cables are secured and screwed tightly? Could you also ensure that the coax cable is in good condition such as no hard bends, kinks, bite marks, or cuts that could be potentially interfering with the communication from the modem? Do you also have any cable splitters in use that you are able to bypass? 

 

Please give these a quick look through and let us know if you find anything. We look forward to your reply. 

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

 • 

106.9K Messages

@XfinityDemitrius wrote;

The signals levels appear to be within specification from my review.

The upstream power is out of spec.......

I am not a Comcast Employee.
I am a Customer Expert volunteering my time to help other customers here in the Forums.
We ask that you post publicly so people with similar questions may benefit from the conversation.

Was your question answered? Please mark an Accepted Answer!tick

Expert

 • 

106.9K Messages

1 month ago

The upstream power is too high / out of spec. The downstream power is on the low / weak side as well. There's a signal / connection impairment somewhere. That can cause random disconnects, spontaneous re-booting of the modem, speed, packet loss, latency problems, and the un-bonding of channels.

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/re-configured. 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, etc.

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.


Good luck with it !

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