A coaxial cable is a common type of data communication cable. ... In hooking up a Comcast cable box, the Comcast manual specifies that you need a 75 ohm coaxial cable with F-type connectors.
Where does the coax cable connect to Comcast?
Connect one end of the coaxial cable to the cable wall outlet and the other end to the Cable In/RF IN on the back of the modem.