Netwoks

Netwoks

1. LAN and WAN

   • LOCAL AREA NETWORK
     • A LAN covers a small area such as one site or building, eg a school or a college.
     • A school network is a LAN
     • A LAN is often connected to a WAN
   • WIDE AREA NETWORK
     • A WAN covers a large geographical area. Most WANs are made from several LANs connected together.
     • The internet is a WAN
     • A network of ATM machines is a WAN

2. ADVANTAGES

   • Sharing devices such as printers saves money
   • Files can be easily shared
   • Security is good because users cannot seeother users files unless it is on a standalone computer
   • Data is easily backed up to the file server

3. DISADVANTAGES

   • Purchasing the network cabling can be expensive
   • Managing a large network requires training and a network manager usually needs to be employed
   • If the file server goes down the network becomes inaccessible
   • Viruses can be shared over the network to a large number of computers
   • Hacking can become easier with WANs so a firewall is usually necessary

4. The BUS Network

   • Advantages
     • It is easy to install
     • It is cheap to install and doesnt require much cabling
   • Disadvantages
     • If the main cable gets damaged or fails, the whole network will fail
     • Every computer on the network 'sees' all of the data on the network therefore becoming a security risk
     • As more work stations are added to the network, the performance of the stations will suffer

5. The RING Network

   • Each device is connected to 2 other devices
     • This forms a ring that signals can pass around
   • Each packet of data goes around to every station until it reaches its desired station
   • Advantages
     • Data can be shared easily
     • There are no data collisions
   • Disadvantages
     • If the main cable fails then the whole system will go down