Xfinity and Arris role in upstream power levels

I thought I would share my experience to help others who have struggled with the same issue.

Symptoms: Dropped video and audio feeds on Zoom, Teams, FaceTime across wired and wireless connection using Xfinity Internet service and a new Arris G34 Router.  If found this problem showed up related to numerous Arris Routers with Xfinity Internet.

The reader’s digest is that when you have only internet service from Xfinity (without a Set-top box or TVs connected via coax, the QAM Power level does NOT fall into the 45 - 51 dBmV range that Arris routers expect.   This results in lost / dropped connections.  

The solution is to get the setup “tuned” to the right power level.   The Arris people helped me log into my router and navigate to Connection - WAN, then look at the QAM upstream values to identify the problem.  I called Xfinity and when I described the problem, the agent immediately scheduled a service call, without doing more trouble shooting.  The Xfinity rep came out, looked things over and commented that they usually only set the QAM Power to be 55 dBmV or lower.   He thought Arris was a little finicky with their range.  That said, he added 2 two-way Coax connectors to my setup to create the “fake load” of extra devices and got my QAM upstream values to 48.xxxx.   

Everything’s been fine for the past 24 hours, so I’m crossing my fingers.  

I guess it would not hurt if Arris built some intelligence into their device to “adjust the upstream signal” for people who only use the routers for internet.  

If I had not found the solution, this router was going back to the store for another brand.  

That said, I did spend upwards of 30 hours getting to the bottom of this problem, including another Xfinity service call last weekend.  I’m hoping I save you some of the time/energy I spent to get to the solution.