Networks

Networks

1. disadvantages

   • The cost of cabling and setting up can be high.
   • A virus can spread through a network very quickly (Infecting each computer)
   • Hackers may gain unauthorised access to files saved on a network server.
   • Networks can fail to work properly - causing loss of access to data, hardware and software.

2. advantages

   • Software can be shared.
   • Hardware (peripheral devices) can be shared.
   • Data can be shared.
   • Networked computers can be centrally controlled by a network manager.
   • Files stored on a server allow for easier back-up schedules than if the files were stored on multiple computers.

3. bus network

   • Disadvantages
     • Speed of data is slow.
     • If the network cable breaks, none of the computers can access the network.
   • Advantages
     • Cheap network to set up.
     • If a computer fails the network continues to work.

4. Ring network

   • This type of network topology is very organized. Each node gets to send the data when it receives an empty token. This helps to reduces chances of collision. Also in ring topology all the traffic flows in only one direction at very high speed.
   • Even when the load on the network increases, its performance is better than that of Bus network.
   • There is no need for network server to control the connectivity between workstations.

5. Star network

   • In a star network, all computers are connected directly to one big computer called a server using hubs or switches.
   • This is good because if one cable breaks, all of the other cables will still work .
   • It is fast because each computer has its own line to the server.
   • The disadvantage to it is that it is expensive to buy the hardware like hubs and switches.

6. Services and hardware used in networks

   • Internet
     • The internet is a WAN which is made up of many other smaller networks.
   • Extranet
     • An extranet is an external network which can be viewed by many different people at an organisation such as employees, suppliers and shareholders.
   • Intranet
     • This internal network is private to one organisation, viewable to employees only
   • Routers
     • These are used to allow different networks to communicate. They can connect a network in a home to wider such as the internet.
   • Switches
     • Switches are used to connect different computers together as part of a network .
     • gateways
       • These allow two different networks to speak to one by translating data.
       • bridges
         • These are used to join - or bridge - two LANs together to form one larger network.
         • Packet switching
           • Switches can speed up networks by only sending packets of data to the computers which need the data. This means that less data is travelling unnecessarily around the entire network.