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I purchased a Arris SB8200 cable modem. It worked for several months until one of your contractors removed an old phone line box after a new phone modem was installed. The internet modem status page showed it all of the channels locked, but no upstream data being transmitted. The Cox repairman that came out said Cox has been having problems with the SB8200 modems randomly failing for no reason.
I put back in an older SB6182 and the internet works now. I am able to see that the internet still slows down and occasionally drops.
I contacted Arris tech support and they said that the problem is with the signal strength. I am only getting around 35 dbmv to 38 dbmv upstream. "I reviewed the screenshots you sent and it seems that your SB8200 is currently able to receive signal from your internet provider, downstream channels are at the specified range, unfortunately upstream channels are not how we expected, according to channel type and frequency upstream power levels must be at a range from 45 dbmv (min) to 51 dbmv (max) to let your modem deliver its potential. This is a common issue our customers have when the ISP do not provide the signal that modem requires, that can be the cause of intermittent connection and slow speed issues."
I have had several issues with service over the years, signal strength related, cable and internet. All of the coax and splitters in my house house have been replaced, other than the run from the pole to the house. Each repairman that has come out, refuses to replace it. How can you resolve this? Is it a problem with cable between the house and the pole, or is it a problem with your infrastructure further up the line?
What is the minimum signal strength or standard that Cox should be providing?
Here is a FAQ on what DOCSIS signal levels should be. If you want, post the signal levels for review.
Everything I can find indicates that an upstream signal level should be between 40-52 dBmV for DOCSIS 3.0, and 45-51 dBmV for DOCSIS 3.1. I was unable to post a picture of my upstream signal levels, but they were 39.2 dBmV. What can be done to achieve acceptable signal levels? Additionally, the modem was only able to bond to 4 upstream channels, not the full eight the modem supports.
This morning, signal levels are down to 37.7 dBmV.