Flaky internet MB8611 modem + Google Mesh/Amazon eero

I have been having flaky internet since I moved to a new address and started using MB8611 Modem. I live in a cull de sac, all my neighbors do not have flaky internet at the same time my internet is down. I have tried restart, restart once every 2 days etc but it does not seem to work.

I looked at the event log on the modem. I found this, for 24 minutes it seems like the modem was unusable. How can this issue be resolved?

Event Log

Time	Priority	Description
14:23:49 Tue May 28 2024	Critical (3)	UCD invalid or channel unusable;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
14:23:49 Tue May 28 2024	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
14:24:02 Tue May 28 2024	Critical (3)	UCD invalid or channel unusable;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
14:24:22 Tue May 28 2024	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
14:34:35 Tue May 28 2024	Critical (3)	UCD invalid or channel unusable;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
14:34:36 Tue May 28 2024	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
14:34:39 Tue May 28 2024	Critical (3)	UCD invalid or channel unusable;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
14:34:40 Tue May 28 2024	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
14:34:52 Tue May 28 2024	Critical (3)	UCD invalid or channel unusable;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
14:34:52 Tue May 28 2024	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
14:35:08 Tue May 28 2024	Critical (3)	UCD invalid or channel unusable;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
14:35:08 Tue May 28 2024	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
14:35:11 Tue May 28 2024	Critical (3)	UCD invalid or channel unusable;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
14:35:11 Tue May 28 2024	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
14:35:24 Tue May 28 2024	Critical (3)	UCD invalid or channel unusable;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
14:35:24 Tue May 28 2024	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
14:35:34 Tue May 28 2024	Critical (3)	UCD invalid or channel unusable;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
14:35:52 Tue May 28 2024	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
14:46:06 Tue May 28 2024	Critical (3)	UCD invalid or channel unusable;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
14:46:06 Tue May 28 2024	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
14:46:08 Tue May 28 2024	Critical (3)	UCD invalid or channel unusable;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
14:46:08 Tue May 28 2024	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
14:46:10 Tue May 28 2024	Critical (3)	UCD invalid or channel unusable;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
14:46:10 Tue May 28 2024	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
14:46:24 Tue May 28 2024	Critical (3)	UCD invalid or channel unusable;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
14:46:24 Tue May 28 2024	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
14:46:39 Tue May 28 2024	Critical (3)	UCD invalid or channel unusable;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
14:46:39 Tue May 28 2024	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
14:46:54 Tue May 28 2024	Critical (3)	UCD invalid or channel unusable;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
14:46:54 Tue May 28 2024	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
14:47:05 Tue May 28 2024	Critical (3)	UCD invalid or channel unusable;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
14:47:07 Tue May 28 2024	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;

Responses

EG

Expert

•

110.3K Messages

11 months ago

What do the modem's signal stats look like ? Try getting them here; http://192.168.100.1

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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EG

Expert

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110.3K Messages

11 months ago

Yes. Most of the 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 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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S

srinda23

3 Messages

@EG

Awesome thank you for this. what do you look for exactly? When you say the power levels are out of spec, what should it be?

I also tried to get a tech to come and take a look. Do you think he/she would be able to help with the upstream connectivity?

11 months ago

0

EG

Expert

•

110.3K Messages

@srinda23

Awesome thank you for this.

Quite welcome !

what do you look for exactly? When you say the power levels are out of spec, what should it be?

Here's what to look for;

Specification Min Max

Downstream Power Level

Cable Modems -10dBmV +10dBmV

Gateways and EMTAs -7dBmV +7dBmV

Downstream Signal to Noise Ratio 35dB -

Upstream Power Level +35dBmV +50dBmV

I also tried to get a tech to come and take a look. Do you think he/she would be able to help with the upstream connectivity?

Specification	Min	Max
Downstream Power Level
Cable Modems	-10dBmV	+10dBmV
Gateways and EMTAs	-7dBmV	+7dBmV
Downstream Signal to Noise Ratio	35dB	-
Upstream Power Level	+35dBmV	+50dBmV

Yes. That is their specialty ! Be advised that there could be a $100 dollar charge if they find that the problem lies with your wiring / equipment rather than theirs.

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

11 months ago

0

XfinityMarcos

Official Employee

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2.3K Messages

11 months ago

Hi srinda23, you provided awesome details in your post, and thank you for taking the time to visit our Forum 😊. Were you able to schedule a tech visit, and if so, how did it go? @EG, thank you for the keen insight as well 🙌.

0

EG

Expert

•

110.3K Messages

11 months ago

@XfinityMarcos

It's why I lurk !!! :-)

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srinda23

Flaky internet MB8611 modem + Google Mesh/Amazon eero

EG

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srinda23

EG

XfinityMarcos

EG

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