1.4 Wired and wireless networks

1.4 Wired and wireless networks

1. LAN

   • Local area network
   • small geographical area, singular building or site
   • own infrastructure of cabling and network hardware, useful for certain distances and practacalities

2. WAN

   • Wide are network
   • used in a school and shop to span over a larger geographical area
   • external hardware and external infrastructure satellite, phone lines and the internet
   • Made up of a community of LANs

3. client server and peer to peer

   • These are ways to set up a network to share data and service
   • client server
     • network relies on a central server
     • all clients (devices) request services from the central server
     • additional hardware needed, i.e. high end powerful servers
     • all files can be stored centrally on a client server
       • all computers can access files from any computer
       • all computers can update central databases
     • backups easily managed as these can be done centrally from file server
     • high traffic
     • antivirus and firewall can be installed
     • useful for many computers but can be high traffic environment
   • peer to peer
     • all computers have equal status
     • each device can act as a client and a sever
     • all computers can request and provide network services
     • no additional hardware/software needed to set up
     • user has to log onto the same computer every time
     • responsible for own backups
     • software installation has to be local

4. packets

   • data sent over a network is broken down into packets
   • each packet contains the address of both the sender and the receiver, IP adress
   • packets also contain a sequence number
   • packets have a lifespan so that they don't use up data inside the receiver's cloud forever

5. Wireless Access Point

   • allows for wireless devices to connect to a network
   • includes connections through wifi and bluetooth
   • WAPs provide internet access in public places

6. router

   • an interconnection device used yo connect two or more devices
   • contain a routing table with a list of IP addresses and common routes for packets to take
   • routers examine packets IP addresses
   • the router will apply a subnet mask to identify a network and decide which network the packet should be forwarded to
   • allow packets from different network types to be exchanged

7. switch

   • data collision occurs when two packets sent into the network at the same time
   • switch is an interconnection device connects two or more devices together and helps solve data collisions from happening
   • data packet arrives at the switch, destination address is examined, switch creates a direct connection to that device

8. DNS

   • domain name server
   • finds the IP address of the web server
   • matches URLs and IP addresses together

9. fibre optic

   • data transmitted using light through glass
   • transmitted at speed of light