Computer Science OCR 1.3.1

Computer Science OCR 1.3.1

1. Topologies

   • Mesh
     • What is Mesh?
       • Each computer is conneced to every other computer in a network
     • Also known as peer to peer model
     • Pros
       • Decentralised so there is no one point of failure for the network
     • Cons
       • High cost
   • star
     • What is star?
       • When all devices are connected to a central server/switch common for LAN
     • Pros
       • Devices can be added
       • Many devices can access the server at a time
     • Cons
       • If the central server fails, the whole network goes down
       • Expensive to set up
     • Also known as Client-server model
   • The way a network is setup.

2. Network Harware

   • Switch
     • Using MAC addresses to send data to the right device in a network
   • router
     • Uses IP addresses to send the device to the right network
   • Network Interface Card
     • Allows computers to access the network
   • Wireless access point
     • Allows wireless capable devices to access wired networks
   • HUB
     • Sends data to all devices connected
   • Modem
     • Converts Electrical signals into analogue signals

3. Network

   • LAN
     • Local area network
   • WAN
   • Factors affecting speed
     • Number of devices connected
     • Bandwidth
       • The maximum amount a network could transfer per second.
     • Number of transmission errors

4. Internet

   • Cloud
     • The cloud is a service to serve as the different hardware without the need to purchase the hardware itself
   • Hosting
   • DNS
     • Domain Name service
     • Domain names and Internet Service provider