Networks

Networks

1. Network Protocols

   • Layers
     • A layer is a group of protocols which have similar functions.
     • Layers are self-contained - protocols in each layer don't need to know what's happening in other layers.
     • Each layer serves the layer above it.
   • HTTP
     • Used by web browsers to access websites and communicate with web servers.
     • Hyper text transfer protocol
   • HTTPS
     • More secure version of HTTP, encrypts all information sent and received.
     • HTTP secure
   • FTP
     • File Transfer Protocol
     • Used to access edit and move files on a network.

2. Types of networks

   • Lan
     • Covers a small geographical area.
     • All hardware owned by organisation.
     • Either wired or wireless.
     • e.g. School, businesses, universities
   • Wan
     • A WAN connects LAN's from different geographical locations.
     • Organisations hire infrastructure.
     • Connected by fibre or copper telephone lines, satellite links or radio links.
     • Usually more expensive than LAN's.
     • e.g. The internet

3. Hardware

   • NIC
     • Network interface controller.
     • Allows a device to connect to a network.
   • Swiches
     • Connect all devices on a LAN.
   • Routers
     • Responsible for transmitting data between networks.
     • Used in homes or offices to connect the LAN to the internet.