How Cable Modems Work

Inside the Cable Modem

Cable modems can be either internal or external to the computer. In some cases, the cable modem can be part of a set-top cable box, requiring that only a keyboard and mouse be added for Internet access. In fact, if your cable system has upgraded to digital cable, the new set-top box the cable company provides will be capable of connecting to the Internet, whether or not you receive Internet access through your CATV connection. Regardless of their outward appearance, all cable modems contain certain key components:

  • A tuner
  • A demodulator
  • A modulator
  • A media access control (MAC) device
  • A microprocessor