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"Dynamic Range Window violation" warnings

New Poster

"Dynamic Range Window violation" warnings

For the past few days, My wifi has been going off randomly throughout the day and I have been looking at my SB8200 logs, and it is showing a LOT of "Resetting the cable modem due to docsDevResetNow" and "Dynamic Range Window violation" which causes everything to go wrong. I have one 4 way splitter installed by a xfinity tech when we built the house.  Can anyone help?Screen Shot 2019-01-16 at 5.45.25 PM.pngScreen Shot 2019-01-16 at 5.46.06 PM.png

Gold Problem Solver

Re: "Dynamic Range Window violation" warnings

Your images are not visible, probably because you are a new poster and the pics require moderator approval. That could take a while. If you don't want to wait you could upload the images to a file sharing site and post links to them here, or copy and paste the text.

 

Problems with Internet service are often due to a poor connection between your equipment and Comcast's network, usually in or near your home. "Dynamic Range Window violation" messages in the error logs generally have the same cause. "docsDevResetNow" is a reset command from Comcast, usually sent as a troubleshooting step, or when you request a reset in My Account.


If you want to troubleshoot this yourself, please see Connection Troubleshooting Tips. If you have Gigabit service, also see https://forums.xfinity.com/t5/Your-Home-Network/Troubleshooting-Gigabit-internet-speeds/m-p/3145413#....

If you are using Wifi it's best to switch to an Ethernet cable connection if possible while measuring speed and checking the reliability of your connection to Comcast.

If you can't find the problem or you'd rather have Comcast do the troubleshooting, call them at the phone number on your bill or 1-800-Comcast, or chat with them using the Internet Support option at https://support.xfinity.com/chat. If they can't fix the problem remotely, insist they send a tech out to identify the cause and correct it.

If the tech finds bad coax, splitters, amplifiers, or connections in your home (even if Comcast originally supplied them) you'll probably have to pay for the visit unless you have their Service Protection Plan (https://www.xfinity.com/support/articles/service-protection-plan, closed to customers that don't already have it). If the trouble is due to a faulty Comcast modem, eMTA, gateway device, or anything outside your home, you shouldn't be charged.

Expert

Re: "Dynamic Range Window violation" warnings

The downstream power level figures and the SNR's are o/k. Please also post the upstream power level figures.



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New Poster

Re: "Dynamic Range Window violation" warnings

Sure thing, sorry. Here you go.Screen Shot 2019-01-19 at 6.58.02 PM.png

Expert

Re: "Dynamic Range Window violation" warnings

Can't see this pic for some reason.  

You could try hosting it at one of those free third-party pic hosting sites and post the link to it here.

 



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? Mark the post as Best Answer!
Gold Problem Solver

Re: "Dynamic Range Window violation" warnings


@bsiegel13 wrote: [ Upstream Bonded Channels image]

The image is visible now.

 

There is a large 9 dB difference between the lowest and highest upstream levels. A difference greater than 12 dB triggers a Dynamic Range Window violation, and your modem is uncomfortably close to that. The most likely cause, as previously stated, is a poor connection between the modem and Comcast's network.

 

Please follow the troubleshooting instructions in my previous post.