Networks

Networks

1. Advantages

   • Sharing devices such as printers saves money.
   • Site (software) licences are likely to be cheaper than buying several standalone licences.
   • Files can easily be shared between users.
   • Network users can communicate by email and instant messenger.
   • Network users can communicate by email and instant messenger.
   • Data is easy to backup as all the data is stored on the file server.

2. Disadvantages

   • Purchasing the network cabling and file servers can be expensive.
   • Managing a large network is complicated, requires training and a network manager usually needs to be employed.
   • If the file server breaks down the files on the file server become inaccessible. Email might still work if it is on a separate server. The computers can still be used but are isolated.
   • Viruses can spread to other computers throughout a computer network
   • There is a danger of hacking, particularly with wide area networks. Security procedures are needed to prevent such abuse, eg a firewall.

3. types

   • The bus network
     • In a bus network all the workstations, servers and printers are joined to one cable (the bus). At each end of the cable a terminator is fitted to stop signals reflecting back down the bus.
   • The ring network
     • In a ring network each device (workstation, server, printer) is connected to two other devices, this forms a ring for the signals to travel around. Each packet of data on the network travels in one direction and each device receives each packet in turn until the destination device receives it.
   • The star network
     • In a star network each device on the network has its own cable that connects to a switch or hub. A hub sends every packet of data to every device, whereas a switch only sends a packet of data to the destination device.

4. components

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