1.5 network topologies protocols and layers

1.5 network topologies protocols and layers

1. Networks

   • What is a network? A network is a number of computers linked together to allow them to share resources
     • Networked computers can share hardware, software and data
     • Networks are all around you; in school, in offices, at work.

2. Key words:

   • Topologies
   • Mesh network
     • Where some or all of the workstations or other devices are connected directly to each other
       • Most are usually connected to the node that they exchange the most data with.
   • Star Network
     • Each device is connected by an individual cable directly to the server
       • Most reliable of topologies
         • Usually the layout of choice in most schools and offices
   • Encryption
     • Ethernet
       • Stable connection
         • Reduced possibility to be hacked
           • More secure
           • Faster traffic speed
             • Generally will have a good quality signal
     • Method of unscrambling data with a key code that makes no sense
       • Encryption is used, therefore if intercepted, data will have no meaning
       • In order to read dat, user is ordered to decrypt the data using the key
     • Using any type of wfi people can join and sniff out packets of data from other users
   • Wi-Fi
     • Cheap set up costs
       • More vunerable to hacking
         • Can connect multiple devices without need for extra hardware
           • user doesn't have to be tied dowm to one specific location
             • Can drop off
               • means wireless frequency
       • Signal quality will reduce through walls and obstructions
         • Interference can occur
           • Less disruption to the building due to no wires
             • Connection is not as stable as wired networks
         • May not be able to receive signal
           • Tend to have low trandfer speeds

3. IP adresses

   • A unique string of numbers separated by full stops that identifies each computer using the internet protocol to communicate over a networkl
     • They have a similar meaning to a postcode
       • An example of an IP address is 192.168.1.23
         • They also have different classes which identify the class of a network

4. MAC addresses (media access control addresses) uniquely identify a device on a network adapter that the device is using

   • Mac Addresses
     • This enables you to distinguish between different devices
     • Embedded into the device when it is manufactured and the owner cannot change it.
   • The Mac address is a unique code that is built into the network interface card (NIC)
     • Each address is individual and made up of 48 bits
     • Example: AA-34-G4-44-23-F1

5. Protocols