Networking

TCP/IP Five-Layer Network Model

• Physical Layer: represents the physical devices that interconnect computers and includes the specifications for the networking cables and the connectors that join devices together, along with specifications describing how signals are sent over these connections.

• Data Link Layer / Network Interface / Network Access Layer: responsible for defining a common way of interpreting these signals so network devices can communicate

  • Ethernet standards define a protocol responsible for getting data to nodes on the same network or link

• Network Layer / Internet Layer: Allows different networks to communicate with each other through devices known as routers

  • Internetwork: a collection of networks connected through routers (the internet)

• The Transport Layer: sorts out which client and server programs are supposed to get that data

  • Transmission Control Protocol (TCP): provides mechanisms to ensure data is reliably delivered

  • User Datagram Protocol: lacks mechanisms

• Application Layer: the contents of the package