Unit 1.4 Wired and Wireless Networks

Unit 1.4 Wired and Wireless Networks

1. Why do we have networks?

   • To communicate/ share resources:
     • Hardware
     • Software
   • To connect devices to one another

2. Arpanet

   • First ever network
   • Was a network of US missile silos

3. Data Protection Act

   • AKA DPA
   • Originally made in 1984.
     • Updated in 1998
       • To be updated again on 25/5/2018 and will be known as GDPR
   • Has to be updated because:
     • More people are using the internet, showing more and more flaws
     • More and more people buying computers and other devices
   • DPA Principles are:
     • Fairly and lawfully processed
       • Adequate, relevant and not excessive
         • Accurate and up to date
           • Kept for no longer than necessary
             • Secure
               • Not transferred to other countries without adequate protection

4. Difference between WWW and the internet

   • The internet is hardware
   • WWW is software

5. LAN and WAN

   • LAN
     • Small Geographical area
       • Cable infrastructure is only owned by the users
     • E.g
       • Home network
         • School network
           • Network in a shop
     • Backbone connects wiring centres using fibre optic cables
   • WAN
     • Over a large geographical area
       • The internet
         • You only own part of the infrastructure, main part is owned by the likes of BT and Virgin etc.

6. Ethernet Cables

   • Have a maximum distance of 185m
   • If you go further than 185m, you just lose the signal

7. Bandwidth

   • Communicated data that is happening at any one time
   • The greater the bandwidth, the quicker everything connected to the network works

8. Client server and Peer - to - Peer

   • Client Server
     • Relies on a central server (star network)
     • They have to request access which is granted by server
     • Additional hardware is needed
     • Can restrict what other devices that are connected to the network cand do/access
     • The server stores user account details and files.
   • Peer - to - Peer
     • No server
     • All computers have equal status
     • All devices can act as a client and as a server
     • No need for additional hardware
   • Vs
     • Backup:
       • Client server ~ only need to backup server and all is backed up
       • Peer - to - Peer ~ has to be done on each device
     • Virus and firewall protection
       • Peer- to - Peer ~ has to be done on every device
       • Client server ~ Just needs to be on central location
     • Suitabilty for traffic
       • Peer - to - Peer ~ more suitable for low traffic
       • Client Server ~ more suitable for high traffic