Networks

Networks

1. Advantages

   • Hardware can be shared.
   • Software can be shared.
   • Data can be shared.
   • Netwroked computers can communicate.
   • Networked computer can centrally be controlled by the newtwork manager.

2. Disadvantages

   • The cost of cabling and setting up can be high.
   • A virus can be spread through a network very quickly.
   • Hackers may gain unauthorised access to files on the server.
   • Networks can fail to work properly.

3. Servers

   • A file server
     • Its a computer on a network that holds files that can be used by other computers on the same network.
   • A client network
     • Its a server network that has one computer acting as the file server.
   • A peer to peer network
     • In peer to peer network all computers are equal importance.

4. Topologies

   • Star network
     • Advantages
       • If a cable or computer breaks, all the other computers will still be able to access the file server.
       • Direct access to the file server means the access is faster.
     • Disadvantages
       • Expensive to install cause cabling.
       • File servers fail all computers fail
   • Bus network
     • Advantages
       • Cheap network to set up.
       • If a computer fails, the whole network continues to work.
     • Disasvantages
       • Speed of data is slow.
       • If the network cable breaks down, none of the computer can acess the network.
   • Ring network
     • Advantages
       • Cheaper network to set up
       • Data speed is continuous
     • Disadvantages
       • If any computers or the network cable breaks, it can affect the whole network.

5. Nets

   • An intranet
     • A Network provides similar services to the internet but only avaliable within one company/establishment
   • An extranet
     • Part of an intranet that can be accsessed by authorised members of the public.
   • World wide web
     • The collection of multimedia info or resources avaliable on the internet.

6. Security

   • It can be protected by...
     • User names/passwords
     • Firewalls
     • Access rights
   • Network could be protected from viruses.
     • Firewall
     • Anti virus software

7. Data transmision

   • Switch
     • A device that filters data packets and forwards them between segmentsof the network.
   • Network interface card
     • Computer hardware, generally installed inside the computer or peripheral , that allows devices to connect to a wired network.
   • Router
     • A device that forwards data packets along a network.They determine thes best path for forwarding the packets, by communicating with other routers.
   • Gateway
     • A system to allow a LAN to connect with a WAN such as internet.
   • Bridge
     • Connects a LAN to another LAN.