Cable Modems

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A cable Internet connection is usually available as part of a cable access TV (CATV) service.

• CATV network is often described as hybrid fiber coax (HFC)
  • it combines a fiber optic core network with copper coaxial cable links to customer premises equipment
  • can also be described as broadband cable or just as cable
• Cable based on the Data Over Cable Service Interface Specification (DOCSIS) supports downlink speeds of up to 38 Mbps (North America) or 50 Mbps (Europe) and uplinks of up to 27 Mbps
  • DOCSIS version 3 allows the use of multiplexed channels to achieve higher bandwidth
• Installation of a cable modem follows the same general principles as for a DSL modem
  • interfaced to the local router via an RJ45 port
  • interfaced with the access provider’s network by a short segment of coax terminated using threaded F-type connectors
    • coax then links all the premises in a street with a cable modem termination system (CMTS)
      • forwards data traffic via the fiber backbone to the ISP’s point of presence and from there to the internet