1.5 Network Topologies

1.5 Network Topologies

1. What is a network?

   • a computer network is a number of computers linked together to allow them to share resources
     • Networked computers can share hardware, software and data

2. Keywords

   • Topology
   • Mesh Network
   • Star Network
   • WiFi
   • Encryption
   • Ethernet
   • IP address
   • MAC addressing
   • Protocols
   • Layers
   • Packet Switching

3. A mesh network is where some/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

4. In a star network, each device is connected by an individual cable directly to the server.

   • They are usually the layout of choice in schools and offices because they tend to be the most reliable of the topologies
     • its very reliable and no data collisons can occur
     • its very expensive and there is extra hardware to buy
       • Server - Switch - workstations
     • mesh network is better to use because there's a high level of dependance of a single hub in Star Network and if the central devise fails the whole network fails

5. Ethernet Benefits

   • Stable connection
   • Reduced possibility to be hacked
   • More Secure
   • Faster Traffic Speed
   • Generally will have a good quality signal

6. WiFi

   • cheap set-up costs
   • more vulnerable to hacking
   • the signal quality will reduce through walls or obstructions
   • interference can occur
   • can connect multiple devices without the need for extra hardware
   • less disruption to the building due to no wires being installed
   • user not tied down to a specific location
   • may not be able to receive signal
   • tend to have slow transfer speed
   • the connection is not as stable as wired networks and can 'drop off'
   • WiFi is a Wireless Frequency
     • Radio waves are used to transmit data packets without the need for wires
     • This method is slower and more vulnerable to attack but it removes the needs for cabling and networks
     • This means that it can be set up in remote locations such as in vehicles, in parks or on planes

7. Encryption is a method of scrambling data with a key code which makes no sense

   • On an open or public WiFi network anyone can join and sniff out packets of data from other users.
   • Therefore encryption is used. If intercepted the data will have no meaning.
   • In order to read the data the user is required to decrypt the data using the key

8. IP Address is a unique string of numbers separated by full stops that identifies each computer using the Internet Protocol to communicate over a network

9. MAC addresses, (Media Access Control Addresses) uniquely identify a device on a network by identifying the network adapter that the device is using

10. Network protocols are a set of rules or conventions which control the communication between devices on a network

11. Layers

    • As a packet is prepared the data travels through layers where protocols manage it, adding or removing extra information as required
      • Network communications standardiesed to ensure different types of hardware and software are able to communicate. It also makes troubleshooting if an error occurs

12. Packet Switching

    • A mode of data transmission in which a message is broken into a number into a number of parts which are sent independently, over whatever route is optimum for each packet, and reassembled at the destination
    • Data is split into individual packets. The router reads the packet and sends it. The receiving device will reassemble the packets into orders. If a packet is missing it will send an error message. The sender will send a new packet. It will calculate the checksum and a confirmation message will be sent.

13. IP addresses also have different classes which identify the class of Network that the user is on

14. A user is more likely to upgrade to a b series router from a n series router because it provides additional bandwidth from 2.4-5 GHZ and carries more non-overlapping channels will result in less interference

15. Protocols mindmap

    • 1.5 Network Topologies Protocols

16. TCI/IP is the protocol that transmits data between different networks