Comcast has a site to help determine what 3rd party modem will work with your Internet package: https://mydeviceinfo.xfinity.com/ https://mydeviceinfo.xfinity.

Comcast has a site to help determine what 3rd party modem will work with your Internet package: https://mydeviceinfo.xfinity.com/ https://mydeviceinfo.xfinity.com/ Sign in, it takes a look at what speed/connection you have and then will recommend a list. Or don't sign in and just specify your address. It'll tell you the speeds available at your location. Select the speed and it'll list out the modems they officially support, including ones with phone support. The ones that everyone I know has is the ARRIS SB8200 or the Motorola MB8600. Both support Docsis 3.0 up to something like 1.4Gbps. They're $150 or so, so you'll break even in a little over a year.