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Good evening, I’m trying to get to the bottom of whether or not Xfinity did something to the lines in my area as part of a recent “network enhancement” that is now causing the Arris CMTS to put my modem via a profile config update on bad channels multiple times a week overnight the last couple weeks. When this occurs, I wake up to it and the download speed is virtually non existent. It isn’t until I power cycle the device and it puts it back on presumably fine/clear channels that everything returns to normal.

As far as timeline, the CMTS wasn’t making these dynamic profile update changes to these presumably bad channels until after Xfinity did “network enhancement” line work back on 4/10 and follow up work on 4/14. Almost immediately after the 4/14 work, that night is when I started seeing the issues with my modem the next morning on 4/15. Since then, the CMTS has been putting me on bad channels 4 times now, overnight, between 1AM and 7AM EST, most recently last night. It’s happened on random nights and as far as i can tell, has never once happened during the day or evening, only overnight.

Unfortunately, due to catching it as I wake up and working from home, I haven’t had a chance yet to see what channels its on when the issue occurs or if I can even get into the admin GUI to get the channel/logs because I have to prioritize power cycling it to restore connectivity to start work. However, here are the current channels it’s using while it’s working without issue today:
 

 


Here is the CM codewords after the reboot this morning up until the time of this post:
 


In addition, here is the event log from the most recent occurrence this morning when the CMTS pushed a dynamic update and connectivity subsequently tanked after that, which is what I woke up to. Previous occurrences have produced similar results with the DS profile config update, followed by the speed/connectivity tank, and a T3 timeout like an hour later, but that’s about it. Once I reboot the modem, it’s fine.


Here is my current firmware version as well:


This appears to be the same firmware version others have reported in other threads mentioning the same exact issue.

Any guidance or assistance would be appreciated as Xfinity has basically told me I need to reach out to Arris first even after I mentioned it starting to occur with my G36 after their line work because they don’t have visibility into the CTMS. If you need me to provide you the MAC address of the CM or CMTS, let me know.​​​​​​​

Hello DeityZero,

 

Are you facing intermittent issue on G36 ? If so its been for how long? 

Looking at above cable signal values it seems downstream values are within the range like for ex: Power level on down stream : lowest: 6.7 / highest:7.19 dbmv and SNR: 44.6/40.9 db 

but when checking on upstream power levels : 35 dbmv  (+45 and +51dbmv its too low on comparison with the values.

What we are checking here is the way the signal comes from out to inside the home. There are some important things that should be within a specific range in order for the internet to work properly.

First, the SNR should be above 33 db on all of them. The downstream power should always be between -15 and +15 dbmv, The closer to 0 the better connection. Finally, your upstream power should always be between +45 and +51dbmv

By having the values in less than that, your device will have interrupted connection, slow or no connection at all.

Let me explain the importance of the signal levels, imagine that your (model#) is a cell phone. And If you are on a phone call, all your bars must on full to get a clear communication, however when your bars are below target your communication will be poor.

The coaxial cable is sending poor signals on the upstream channels  and is affecting the device itself to communicate properly, we would recommend that you contact your service provider to make the appropriate adjustments to those levels for you. If they advise that the levels they are sending are within those ranges, this would indicate a possible issue with a faulty cable splitter or a coaxial cable line in your area in need of maintenance

Also, in regarding with Event log, which will be monitored only by Internet Service Provider(ISP).

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