What is the Internet

The internet is not a single network, rather it is an interconnection of many different computer networks


  • Hosts - End systems
  • Communication Links - Fiber, Copper, Radio, Satellite
  • Transmission Rate - Bandwidth
  • Packet Switches - Routers, Switches
  • Protocols - Communication rules
  • Internet Standards - Interoperability
    • RFC - Request For Comments
    • IETF - Internet Engineering Task Force

Network Edge

End systems, access networks, links

Network Core

Packet switching, circuit switching, network structure

  • DSL - Symmetric upstream and downstream (Given a fixed bandwith, upstream and downstream rates are same)
  • ADSL - Asymmetric upstream and downstrea (Given a fixed bandwidth, more focus on the downstream)
  • Coaxial Cable
  • NBN - HAH.

Physical media (not assessable)

  • bit
  • physical link
  • guided media - signals propagate in solid media: copper, fiber, coax
  • unguided media - signal propagate freely, radio