The TCP IP Five Layer Network Model
The Five Layers
Starting from bottom:
- Physical: represents the physical devices that interconnect computers
- Data Link: responsible for defining a common way of interpreting signals so network devices can communicate (eg. ethernet, wireless)
- Network: allows different networks to communicate with each other (through routers)
!!! note "Internetwork" A collection of networks connected together through routers, most famous of these being the Internet.
!!! note "Data Link vs Network" Data Link is responsible for getting data across a single link; network layer is responsible for getting data across a collection of networks.
!!! note "IP" Most common protocol at the network layer is the Internet Protocol.
- Transport: sorts out which client and server programs are supposed to get the data being sent (a node can run multiple clients -- like chrome, email)
- Application: http, smtp etc.
Analogy with package delivery:
Networking devices, and the layers they operate at: