What is the Internet

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

Terminology

• 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