The upgrade raised connection speeds for customers with two of the three Internet packages that Cox offers, and those modems are not compatible with the higher speeds.

Cox cuts some users’ uploads from 30Mbps to 10Mbps—here’s how to avoid it Cox notifies users of speed cut, fails to mention they can keep current plan.

On its website, Cox also maintains a list of modems customers can buy from third-party vendors that will be compatible with its service. Most customers already have the newer equipment, Caudle said.

Not compatible with RCN. No cable modem is compatible with fiber optic, DSL, or satellite services, available from Verizon, AT&T, CenturyLink, Frontier, and others.) ...

Here's our head-to-head review of AT&T against Cox with an in-depth analysis of each internet providers' features and an overview of which one would match your needs.

The Arris SURFboard SB6141 cable modem is the best choice for most people because it's compatible with six of the eight biggest US cable ISPs—including the top three—as well as Cox.

How can you tell? Comcast offers this page that asks you for your Internet speed tier and then allows you to check to see whether your modem is in fact compatible. Cox offers a similar page.

The local cable television company says a few of its Internet customers with computer communications hookups dating back nine or more years must buy new equipment.