Our initial step in the investigation was to review all the DOCSIS 3.0 and DOCSIS 3.1 modems compatible with major ISPs such as Astound (RCN), Charter, Cox, Mediacom, Optimum, Sparklight, Spectrum, WOW, and Xfinity. We then refined our selection to focus on modems that align with the most popular internet plans offered by these ISPs. (Notably, Astound, Optimum, and WOW do not provide a list of approved modems, so it’s advisable to reach out to their customer support for confirmation before making a purchase.)