WiredandWirelessNetworks

WiredandWirelessNetworks

1. The Internet

   • The Internet is a global collection of inter-connected networks
   • It is a Wide Area Network (WAN)
     • A WAN is a network in which devices communicate using resources from a 'thired party carrier' like British Telecom.
     • They are typically set out over a large geographical area
     • WANs use telephone lines, satellites and radiowaves to transport data.
   • By 2020 it is predicted that around 50 billion things will be connected to the internet, this is refered to as the internet of things

2. Client-Server and Peer-to-Peer Networks

   • Client-Server model
     • A server is a powerful computer that provides the services requested by the clients
     • A client is a computer that requests services from a server
   • LANs and WANs
     • LANs are networks spread out over a small geographical area. they are normally only connected to clients inside the LAN and few servers are a part of a LAN.
     • WANs are networks spread out over a large geographical area, they are normally controlled by a third party and they are used for things like banking, email and the internet itself is a WAN.
   • Peer to Peer Networks
     • This network type isn't controlled by a central server and it operates by using the clients in the network
     • There isn't any security for P2P networks so the operators of the networks need to ensure the clients are all protected by antiviruses
     • In P2P networks the users can see other users files and they can communicate with each other without going through a central server

3. Network Topologies

   • Star topology
     • In this network there is a cetral server that all computers directly connect to