navbob's profile

Regular Visitor

 • 

5 Messages

Tue, Dec 22, 2020 10:00 AM

Critical Modem Error: "Started Unicast Maintenance Ranging - No Response received - T3 time-out"

I appear to be having issues with a NETGEAR CM1150V modem (or the upstream wiring). This is my second modem after trying the Xfinity recommended Motorola . I use cable TV, internet, and voice connections. Orbi mesh network for WiFi.

 

Currently paying for the 1 Gbps package and am receiving a sluggish, high latency ~50 Mbps on average. The Xfinity Status Center displays "We're having trouble finding a signal", my wife's work laptop drops internet frequently (no other devices drop the wifi signal), and the modem has "Started Unicast Maintenance Ranging - No Response received - T3 time-out" errors all over the event logs.

 

Any advice on what can be done is appreciated. DSLReports indicates no bufferbloat, Orbi connection seems solid. Modem resets from the Xfinity dashboard don't help. I'm left scratching my head here. 

Responses

EG

Expert

 • 

88K Messages

7 m ago

Please post the *Downstream Power Level*, the *Upstream Power Level*, and the *SNR* (Signal to Noise Ratio) numbers. And the error log entries in their entirety.


Regular Visitor

 • 

5 Messages

7 m ago

Hey thanks in advance for taking a look. Here are the power levels and SNR numbers:

Startup Procedure
Procedure Status Comment
Acquire Downstream Channel 603000000 Hz Locked
Connectivity State OK Operational
Boot State OK Operational
Security Enabled BPI+
IP Provisioning Mode Honor MDD honorMdd(4)
 
Downstream Bonded Channels (Partial Service)
Channel Lock Status Modulation Channel ID Frequency Power SNR Correctables Uncorrectables
1 Locked QAM256 21 603000000 Hz -12.6 dBmV 36.8 dB 35115 9563
2 Locked QAM256 2 489000000 Hz -18.6 dBmV 33.5 dB 632983 340975
3 Not Locked Unknown 3 495000000 Hz 0.0 dBmV 0.0 dB 0 0
4 Not Locked Unknown 0 0 Hz 0.0 dBmV 0.0 dB 0 0
5 Not Locked Unknown 0 0 Hz 0.0 dBmV 0.0 dB 0 0
6 Locked QAM256 6 513000000 Hz -16 dBmV 29.2 dB 477715393 103930085
7 Locked QAM256 7 519000000 Hz -15.2 dBmV 35.5 dB 357643408 91496767
8 Locked QAM256 8 525000000 Hz -15.1 dBmV 35.7 dB 147097 37088
9 Locked QAM256 9 531000000 Hz -14.7 dBmV 35.8 dB 142489 36292
10 Locked QAM256 10 537000000 Hz -14.6 dBmV 35.4 dB 79412 13074
11 Locked QAM256 11 543000000 Hz -14.4 dBmV 35.8 dB 91933 16597
12 Locked QAM256 12 549000000 Hz -13.8 dBmV 36.2 dB 91789 16617
13 Locked QAM256 13 555000000 Hz -12.9 dBmV 36.7 dB 51478 7655
14 Locked QAM256 14 561000000 Hz -12.8 dBmV 36.7 dB 49811 8533
15 Locked QAM256 15 567000000 Hz -12.6 dBmV 36.8 dB 49273 10094
16 Locked QAM256 16 573000000 Hz -12.2 dBmV 37 dB 33708 4304
17 Locked QAM256 17 579000000 Hz -12.9 dBmV 36.7 dB 32395 6866
18 Locked QAM256 18 585000000 Hz -12.3 dBmV 37 dB 34083 8239
19 Locked QAM256 19 591000000 Hz -12.4 dBmV 36.9 dB 23669 3090
20 Locked QAM256 20 597000000 Hz -12.2 dBmV 37 dB 22705 4177
21 Locked QAM256 22 609000000 Hz -12.5 dBmV 36.8 dB 22038 1958
22 Locked QAM256 23 615000000 Hz -12.7 dBmV 36.7 dB 22869 2905
23 Locked QAM256 24 621000000 Hz -13.1 dBmV 36.5 dB 32859 6853
24 Locked QAM256 25 627000000 Hz -13 dBmV 36.5 dB 136170 17686
25 Locked QAM256 26 633000000 Hz -13 dBmV 36.5 dB 122970 9072
26 Locked QAM256 27 639000000 Hz -13.1 dBmV 36.5 dB 21371454 8579092
27 Locked QAM256 28 645000000 Hz -12.5 dBmV 36.8 dB 157173707 1048254
28 Locked QAM256 30 651000000 Hz -13.4 dBmV 36.3 dB 78020 5768
29 Locked QAM256 31 657000000 Hz -13.8 dBmV 36.2 dB 107617 19293
30 Locked QAM256 32 663000000 Hz -13.6 dBmV 36.4 dB 102641 13816
31 Locked QAM256 33 669000000 Hz -13.7 dBmV 36.3 dB 131436 19006
32 Not Locked Unknown 0 0 Hz 0.0 dBmV 0.0 dB 0 0
 
Upstream Bonded Channels
Channel Lock Status US Channel Type Channel ID Symbol Rate Frequency Power
1 Locked ATDMA 1 5120 Ksym/sec 35600000 Hz 51 dBmV
2 Locked ATDMA 2 5120 Ksym/sec 29200000 Hz 52.3 dBmV
3 Locked ATDMA 3 5120 Ksym/sec 22800000 Hz 52 dBmV
4 Locked ATDMA 4 5120 Ksym/sec 16400000 Hz 51 dBmV
5 Not Locked Unknown 0 0 Ksym/sec 0 Hz 0.0 dBmV
6 Not Locked Unknown 0 0 Ksym/sec 0 Hz 0.0 dBmV
7 Not Locked Unknown 0 0 Ksym/sec 0 Hz 0.0 dBmV
8 Not Locked Unknown 0 0 Ksym/sec 0 Hz 0.0 dBmV
 
Downstream OFDM Channels
Channel Lock
Status
Modulation /
Profile ID
Channel
ID
Frequency Power SNR /
MER
Active Subcarrier
Number Range
Unerrored
Codewords
Correctable
Codewords
Uncorrectable
Codewords
1 Locked 0 ,1 ,2 ,3 37 690000000 Hz -14.2 dBmV 35.1 dB 1228 ~ 2867 925090560 816189262 4111870
2 Not Locked 0 0 0 Hz 0 dBmV 0.0 dB 0 ~ 4095 0 0 0
 
Upstream OFDMA Channels
Channel Lock Status Modulation / Profile ID Channel ID Frequency Power
1 Not Locked 0 0 0 Hz 0 dBmV
2 Not Locked 0 0 0 Hz 0 dBmV
 
Current System Time:Tue Dec 22 15:26:24 2020

System Up Time:3 days 08:21:45

 

And here is the event log I captured yesterday:

Capture99.jpg

EG

Expert

 • 

88K Messages

7 m ago

The up and the down power levels are out of spec.  That can cause random disconnects, spontaneous re-booting of the modem, speed, packet loss, latency problems, and the un-bonding of channels.

In a self troubleshooting effort to try to obtain better connectivity / more wiggle room, check to see if there are there 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 types like GE, RadioShack, RCA, Philips, Leviton, Magnavox, and Rocketfish from big box stores like Home Depot, Lowes, Target, Wal-Mart etc. Splitters should be swapped with known to be good / new ones to test

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.

New to the Community?

Start Here