Ethernet connection from Comcast/Xfinity; Data usage; good cable modem recs [View all]

Hi All:

Need some help on three issues:

1) We have cable internet from Comcast/Xfinity. A few years ago, I had a CAT 6 cable run from the house (where the cable modem is) to the garage so that I could have a solid ethernet connection into the garage. For 3 years, it's been working fine. However, the ethernet connection in the garage seems to be on the fritz. Sometimes, it's solid. But, then, on occasion, the internet through the CAT 6 cable goes intermittently dead or completely dead (as it is now). Are there any tools (hardware or software) that I can use to see if there is a problem with the cable itself or to help me diagnose what the issue can be? I've reset the modem, the mesh router (Google) and the switch many times. I need the solid connection for work, and my IT folks are telling me that the the ethernet connection is not good. That's about the extent of my knowledge on something like this.

I can figure out stuff on the computer and networks through trial and error, but this seems to be a recurring problem. For example, I was just about to start a video call yesterday and everything went dead. I used my phone as a hotspot, but luckily the internet came on. I will call Xfinity, but they usually disclaim networks where it is not their equipment (i.e., modem and routers) being used, which is our case.

2) We seem to be hitting the Xfinity monthly data caps quite frequently. We have four people in our house, and on occasion, all four of us are on videocalls to school or work. But we don't download movies etc. I am concerned that there might be a network intrusion that's eating up our data. None of us are massive data users, and I wouldn't think Zoom calls etc. would take up that much data. Our monthly cap is 1.2 TB. Any guidance on software that I can use to see where the data is going?

3) I have a 500mbs plan. I am not sure my modem can handle it though. Does anyone have a recommendation for a good cable modem
for Comcast/Xfinity that can handle these speeds. I actually want to have one that can handle speeds in excess of 500 mbs so that I can benefit from down/up speed upgrades. I used to use Amazon recs for stuff like this, but I no longer trust the reliability of recommended products on Amazon.


Thank you.