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"Dynamic Range Window violation" and poor connection

New Poster

"Dynamic Range Window violation" and poor connection

I have switched back to Xfinity for internet but have not had good connection speeds since it has been turned on. Very unreliable. I bought a new modem Arris sb6183 and new router. The issue is occurring on both my wired computer and wifi connected devices.

16 locked downstream channels. -6.1 to -1.9 dbmv power and 37-43db snr ranges.

4 upstream channels 47-53db range.

I am getting a Dynamic Range Window violation error in the modem log but nothing else. Any ideas? Do I need to get a technician out to look at the lines?
Gold Problem Solver

Re: "Dynamic Range Window violation" and poor connection

Dynamic Range Window violation errors are usually due to an intermittent connection causing problems in the upstream power levels. 47 dBmV on the upstream is OK, but 53 is borderline/too high.

 

To troubleshoot this yourself see Connection Troubleshooting Tips.

 

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).

New Poster

Re: "Dynamic Range Window violation" and poor connection

Thank you for that link. We do have a splitter at the back of the house. I will eliminate that since it's not really needed, as we only have internet service now, and see if that helps drop the upstream power levels.
New Poster

Re: "Dynamic Range Window violation" and poor connection

Just an update...the splitter I saw was for the old dtv service. There is no splitter on the cable coming from the ground and in to the house. I guess I will be calling Xfinity.
New Poster

Re: "Dynamic Range Window violation" and poor connection

Found the issue yesterday. It was actually a bad Ethernet patch cable between the modem and router. Even though the router was new, the cable was old. Everything is running perfectly now.
Official Employee

Re: "Dynamic Range Window violation" and poor connection

Hi Gbarnes. I am so glad to see you were able to resolve your issue. If you need assistance with anything further. Please let us know, we are happy to help. 


I am an Official Comcast Employee.
Official Employees are from multiple teams within Comcast: CARE, Product, Leadership. We ask that you post publicly so people with similar questions may benefit from the conversation.
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