DOCSIS 3.1 cable modems are still developing across the country. However, some businesses and even some households are using DOCSIS 3.1 technology today. If you subscribe to Gigabit plans such as XFINITY 1 Gig or Gigabit Pro, Cable One GigaOne, or Mediacom Xtream Gig, you’ll need a DOCSIS 3.1 compatible cable modem. Some may be offered only through your cable company. However, some companies may let you buy your own modem.