Networks

Networks

1. Topologies

   • Bus
     • The network consists of a single cable that runs through the network
   • Star
     • All computers are connected to a central switch. The switch directs the traffic to the appropriate computer
   • Ring
     • Computers are connected to each other in a ring Communication only goes in one direction
     • No central cable, each connection is between two computers
   • Mesh
     • Circuit switching
       • The data is split into lots of small chunks called packets. Each one is sent independently, likely using different paths and re-assembled after
     • Packet switching
       • A path across the network is established. That path is locked and remains open for the duration of the communication.

2. LAN

   • Local Area Network
   • it is contained within a single geographical area

3. WAN

   • Wide Area Network
   • s a collection of LANs spread across multiple sites and can be used globally

4. Advantages

   • data and resource sharing
   • globalisation, can be used anywhere
   • backups, if they are don't they can ensure no data is lost permanently
   • archives, can free up space when data is no longer in regular use
   • disaster recovery
   • cost can be better in the long run of things by starting up a network

5. Disadvantage

   • security can be a problem if its weak
   • can be quite expensive to start up and require maintenance

6. A network is a group of computers connected together so they can communicate

7. Hardware

   • switch routes packets round a network after analysing and to the device adressed. They are faster and more secure
   • hub routes packets round a network blindly to every device connected. They are considerably cheaper
   • a wireless access point (WAP) is a device that creates a wireless network which other devices can connect
   • a gateway connects together two networks that use different types
   • a network interface card (NIC) is a device that joins the network and connects a computer or other device
   • a bridge connects together two networks that use the same type
   • a router stores the addresses of computers on the network and transfers their data to other devices on the network