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user_4g59b9
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7 Messages

Monday, May 5th, 2025 5:35 PM

Consistent T3 time-out in modem logs

Consistent T3 time-out in modem logs

Problem

I believe this line sums up the problem. Found these in modem event log

2025-5-5, 12:24:33 Critical (3)  16 consecutive T3 timeouts while trying to range on upstream channel 3;CM-MAC=REDACTED;CMTS-MAC=REDACTED;CM-QOS=1.1;CM-VER=3.0;

Network environment

Feel free to ask questions

Modem NETGEAR CM500-100NAS
Gateway UniFi UCG-Max
Access Point UniFi U7-Pro

Customer Information

DM for information

Question

 • 

Updated 

4 hours ago

9

2

0

EG

Expert

 • 

110.2K Messages

12 hours ago

Are you actually experiencing any connection problems, or are you just focusing on the error log entries ? 

What do the modem's signal status values look like ?

Please 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.

1

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user_4g59b9

7 Messages

@EG​  Thanks! I looked into the modem logs after seeing consistent packet loss when streaming and home gaming. We only now installed network gear that allows us clear visibility into our issues. Service connectivity 'succeeds' 5-10 mins after modem reboot. There are no recorded uncorrectable at this moment because I hard reset the modem while troubleshooting.

Startup Procedure

Procedure Status Comment
Acquire Downstream Channel 387000000 Hz Locked
Connectivity State OK Operational
Boot State OK Operational
Security Enabled BPI+
IP Provisioning Mode Honor MDD honorMdd(4)

Downstream Bonded Channels

Channel Lock Status Modulation Channel ID Frequency Power SNR Correctables Uncorrectables
1 Locked QAM256 9 387000000 Hz 8.9 dBmV 41.1 dB 0 0
2 Locked QAM256 10 393000000 Hz 9.1 dBmV 41.3 dB 0 0
3 Locked QAM256 11 399000000 Hz 8.9 dBmV 41.1 dB 0 0
4 Locked QAM256 12 405000000 Hz 8.8 dBmV 40.9 dB 0 0
5 Locked QAM256 13 411000000 Hz 8.5 dBmV 40.6 dB 0 0
6 Locked QAM256 14 417000000 Hz 8.5 dBmV 40.7 dB 0 0
7 Locked QAM256 15 423000000 Hz 8.5 dBmV 40.6 dB 0 0
8 Locked QAM256 16 429000000 Hz 8.6 dBmV 40.7 dB 0 0
9 Locked QAM256 17 435000000 Hz 8.4 dBmV 40.5 dB 0 0
10 Locked QAM256 18 441000000 Hz 8.2 dBmV 40.3 dB 0 0
11 Locked QAM256 19 447000000 Hz 8.1 dBmV 40.3 dB 0 0
12 Locked QAM256 20 453000000 Hz 8.1 dBmV 40.3 dB 0 0
13 Locked QAM256 21 459000000 Hz 8 dBmV 40.2 dB 0 0
14 Locked QAM256 22 465000000 Hz 7.8 dBmV 40.2 dB 0 0
15 Locked QAM256 23 471000000 Hz 7.7 dBmV 40.1 dB 0 0
16 Locked QAM256 24 477000000 Hz 7.7 dBmV 40.1 dB 0

0

Upstream Bonded Channels (Partial Service)

Channel Lock Status US Channel Type Channel ID Symbol Rate Frequency Power
1 Locked ATDMA 8 5120 Ksym/sec 35600000 Hz 43.3 dBmV
2 Not Locked Unknown 5 0 Ksym/sec 16300000 Hz 0.0 dBmV
3 Not Locked Unknown 6 0 Ksym/sec 22800000 Hz 0.0 dBmV
4 Not Locked Unknown 7 0 Ksym/sec 29200000 Hz 0.0 dBmV

(edited)

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11 hours ago

0

EG

Expert

 • 

110.2K Messages

9 hours ago

The downstream power is a tad on the high side but that may not be a problem. The upstream has only one channel locked in. There should be around three to six. This is typically caused by noise ingress into the line(s) / a connection impairment somewhere. First. Try power cycling the modem one more time. This can sometimes help to pull a new / cleaner set of channels. Please post back with how that goes.

2

0

user_4g59b9

7 Messages

Same problem. Since the modem takes minimum 5-10 minutes just to get a lock and provision WAN to its Ethernet output I'm assuming the issue lies beyond CPE.

(edited)

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4 hours ago

0

user_4g59b9

7 Messages

Please escalate this to a local team.

Washington Township, NJ 07853

(edited)

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4 hours ago

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