U

Wednesday, November 6th, 2024 5:28 PM

Unicast Maintenance Range - No Response Received

I've been having issues with the internet for months now. From slow internet to dropouts. Before I was able to game online and stream with no issues and now even TV streaming seems to struggle. No succeed with Chat Assistance, but seems like there's many people in the forum with the same issue.

I have a Motorola MG755O and I keep getting "Started Unicast Maintenance Range - No Response Received - T3 timeout; CM-MAC=XXXXXXX; CMTS-MAC=XXXXXXXX; CM-QOS=1.1;CM-VER=3.0"

From the forums this seems to be a big "No no". What can help in this situation? Thank you.

Expert

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107.1K Messages

15 days ago

Please post the balance modem's RF error log entries in their entirety (copy and paste all of the text) but redact the CM and the CMTS MAC addresses for your privacy or else 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.

5 Messages

@EG

Wed Feb 21 15:34:21 2024    Critical (3)   SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing
 Wed Feb 21 15:34:21 2024    Critical (3)   Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out
 Wed Feb 21 15:34:48 2024    Critical (3)   SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing
 Wed Feb 21 15:34:48 2024    Critical (3)   Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out
 Wed Feb 21 15:34:50 2024    Critical (3)   SYNC Timing Synchronization failure - Failed to acquire FEC framing
 Time Not Established   Critical (3)   SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing
 Wed Feb 21 16:30:10 2024    Critical (3)   SYNC Timing Synchronization failure - Failed to receive MAC SYNC frame within time-out period
 Wed Feb 21 16:30:20 2024    Critical (3)   No Ranging Response received - T3 time-out
 Wed Feb 21 16:30:40 2024    Critical (3)   Started Unicast Maintenance Ranging - No Response received - T3 time-out
 Time Not Established   Critical (3)   No Ranging Response received - T3 time-out
 Thu May 02 20:16:56 2024    Critical (3)   Started Unicast Maintenance Ranging - No Response received - T3 time-out
 Time Not Established   Critical (3)   No Ranging Response received - T3 time-out
 Sat Jun 29 16:16:10 2024    Critical (3)   Started Unicast Maintenance Ranging - No Response received - T3 time-out
 Time Not Established   Critical (3)   No Ranging Response received - T3 time-out
 Mon Jul 08 04:59:04 2024    Critical (3)   Started Unicast Maintenance Ranging - No Response received - T3 time-out
 Time Not Established   Critical (3)   No Ranging Response received - T3 time-out
 Fri Jul 19 03:41:20 2024    Critical (3)   Started Unicast Maintenance Ranging - No Response received - T3 time-out
 Time Not Established   Critical (3)   No Ranging Response received - T3 time-out
 Time Not Established   Critical (3)   TFTP failed - Request sent - No Response
 Time Not Established   Critical (3)   TFTP Request Retries exceeded, CM unable to register  
 Time Not Established   Critical (3)   No Ranging Response received - T3 time-out
 Sun Sep 29 07:04:06 2024    Critical (3)   Started Unicast Maintenance Ranging - No Response received - T3 time-out
 Time Not Established   Critical (3)   No Ranging Response received - T3 time-out
 Tue Oct 08 08:24:01 2024    Critical (3)   Started Unicast Maintenance Ranging - No Response received - T3 time-out
 Time Not Established   Critical (3)   No Ranging Response received - T3 time-out
 Mon Oct 28 15:55:32 2024    Critical (3)   Started Unicast Maintenance Ranging - No Response received - T3 time-out;
 Time Not Established   Critical (3)   No Ranging Response received - T3 time-out;
 Mon Oct 28 19:10:51 2024    Critical (3)   Resetting the cable modem due to docsDevResetNow 
 Time Not Established   Critical (3)   No Ranging Response received - T3 time-out;;
 Tue Nov 05 05:25:01 2024    Critical (3)   Started Unicast Maintenance Ranging - No Response received - T3 time-out;
 Time Not Established   Notice (6)   Honoring MDD; IP provisioning mode = IPv6 
 Wed Nov 06 09:37:56 2024    Critical (3)   Started Unicast Maintenance Ranging - No Response received - T3 time-out

 Downstream Bonded Channels  
  
   Channel Lock Status Modulation Channel ID Freq. (MHz) Pwr (dBmV) SNR (dB) Corrected Uncorrected
1 Locked QAM256 29 579.0 11.0 40.9 0 0
2 Locked QAM256 30 585.0 10.8 40.7 0 0
3 Locked QAM256 31 591.0 10.8 40.7 0 0
4 Locked QAM256 32 597.0 10.6 40.4 0 0
5 Locked QAM256 33 603.0 10.5 40.4 0 0
6 Locked QAM256 34 609.0 10.7 40.4 0 0
7 Locked QAM256 35 615.0 10.8 40.5 0 0
8 Locked QAM256 36 621.0 10.9 40.4 0 0
9 Locked QAM256 37 627.0 11.2 40.4 0 0
10 Locked QAM256 38 633.0 11.4 40.3 0 0
11 Locked QAM256 39 639.0 11.7 40.3 0 0
12 Locked QAM256 40 645.0 12.3 40.6 0 0

 Upstream Bonded Channels  
  
   Channel Lock Status Channel Type Channel ID Symb. Rate (Ksym/sec) Freq. (MHz) Pwr (dBmV)
1 Locked ATDMA 2 5120 29.2 41.0
2 Locked ATDMA 1 5120 35.6 41.5
3 Locked ATDMA 3 5120 22.8 40.5
4 Locked ATDMA 4 5120 16.4 39.8

Expert

 • 

107.1K Messages

15 days ago


This may or may not be the root cause of the problem (YMMV) but it should be addressed regardless.


The downstream power is too high / out of spec. It may be over-driving the front-end receiver circuit of the modem. That can cause random disconnects, spontaneous re-booting of the modem, speed, packet loss, latency problems, and the un-bonding of channels.


Is there a drop amplifier on the coax cable line leading to the modem ? If so, try removing / bypassing it and see. If not, you can try installing a -6 dB forward path-only attenuator pad such as this one on the coax port on the rear of the modem to knock that power level down and see;

https://www.amazon.com/line-Signal-Forward-Attenuator-FPA6-54/dp/B07882H96R 

For areas that have been upgraded to the new Next Gen (mid-split) upload speeds;

https://www.multicominc.com/product/multicom-mul-fpa85-forward-path-attenuator 

These won't affect the upload power which is within specs.

5 Messages

@EG​ 

Thank you! I went ahead and got the -6dB attuanator from a local electronics store and tried. Power Levels are now down to ~5dBmV. I haven't noticed any dropouts (yet) but connection is still very poor. Struggled over streaming services, less than 10Mbps on Speed tests (compared to over 100Mbps I used to get)

Expert

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107.1K Messages

14 days ago

OK is this with a WiFi connection ? If so, as a test, does a computer / device that is hardwired directly to the 7550 with an ethernet cable have the same problem ?

Which speed tier are you actually subscribed to ?

5 Messages

@EG​ 

Tried it with the Ethernet cable and got almost 300mbps (subscriedto 300mbps). Seems like the issue is the WiFi itself and not the connection.

I disconnected all devices from the Wifi and just connected my phone, then my PC and just got around 20ish Mbps. This is onthe 5ghz network of my MG7550, and pretty much just right by where it's located.

If the issue is my router I would be ok with changing it. But would like to make sure that's the issue before taking that step.

Expert

 • 

107.1K Messages

14 days ago

There is no way to truly be sure without actually trying another. It maybe WiFi interference that is local to your premises. Try some stuff first;

https://www.cnet.com/how-to/home-networking-explained-part-2-optimizing-your-wi-fi-network/ 


https://www.smallnetbuilder.com/wireless/wireless-features/wi-fi-ping-spikes-causes-and-fixes/ 

You can Google for more ways to improve your WiFi. Good luck !

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