Network Topologies, protocols and layers Flashcards Preview

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Flashcards in Network Topologies, protocols and layers Deck (25):

What is a Mesh Network?

  • Where some or all of the workstations or other devices are connected directly to each of other.
  • Most are usually connected to the node that they exchange the most data with


What is a Star Network?

A topology where each device is connected by an individual cable directly to the server.

Star networks are usually the layout of choice in schools and offices because they tend to be the most reliable of the topologies.


What type of network topology does this image represent?



What type of network topology does this image represent?



What is a Network Topology? 

 The physical layout of a Network


What are the advantages of using a Star network?

  • They are very reliable.

  • If one connection fails it does not affect the rest of the network.

  • It is relatively easy to add additional devices onto the network.

  • It is relatively fast as each device has its own connection to the switch / server.

  • There are few data collisions


What are the disadvantages of a Star network?

  • There is a high level of dependence on one single, central device.

  • If the central device fails the whole network will fail.

  • The use of a switch or router could increase the cost of the whole network.

  • The performance of the network will be dependent upon the specification of the central device / switch.

  • The number of additional devices that can be added to the network could be restricted by the central device / switch.


What are the advantages of a Mesh Network?

A broken node won’t stop the transmission of data.  A broken device will be ignored by a signal which will find a new node to connect to.

Additional devices will not affect its network connection. 

A mesh topology can handle a high amount of network traffic. Interconnected devices can simultaneously transfer data smoothly and will not complicate the network connection.


What are the disadvantages of a Mesh Network?

  • Maintenance of the mesh network can be hard to manage because it requires continuous supervision 
  • Very expensive to set because it requires a lot of devices.



What is Wi-Fi?

  • WiFi is Wireless Frequency
  • radio waves are used to transmit data packets without the need for wires.  


What is an Ethernet network?

Wired.  Ethernet is the type of wire used to connect the nodes


What are the advantages of a wireless network?

  • cheap set-up costs
  • user is not tied down to a specific location
  • can connect multiple devices without the need for extra hardware
  • less disruption to the building due to no wires being installed


What are the disadvantages are a wireless network?

  • interference can occur
  • the connection is not as stable as wired networks and can 'drop off'
  • it will lose quality through walls or obstructions
  • more open to hacking
  • slower than wired networks


What are the 2 frequencies used by Wi-Fi?

  • 2.4 GHz - Most commonly used
  • 5 GHz - less commonly used


Why is the 5GHZ wi-fi frequency better than the 2.4GHZ wi-fi frequency?

  • The 5GHz frequency offers additional bandwidth over the 2.4GHz frequency.
  • The 5GHz frequency is capable of carrying more non-overlapping channels which will result in less interference



What are the advantages of a wired network?

  • It has a stable connection
  • Reduced possibility of hacking in comparison to wireless
  • More secure
  • Faster traffic speed
  • Generally good quality signal


What are the disadvantages of a wired network?

  • More expensive to set up that wireless
  • User is less portable because they are tied down to a specific location


What is the security risk of using open or public wi-fi?

Anyone can join and sniff out packets of data from other users


How do you keep your information secure when using open or public wi-fi?

Encryption is used so any intercepted data will have no meaning


What steps are followed the establishing a secure (encrypted) session with a website (using HTTPS)?

  1. Client requests HTTPS session
  2. Certificate sent to client from the server
  3. Client creates session key
  4. Encrypted session key is sent to the server
  5. The session key is decrypted with the private key
  6. Session encrypted with session key


How do you know you have a secure (encrypted) session with a website?

  • A tiny padlock appears in your browser window,
  • The website address starts with HTTPS



What is the encryption method used when accessing a website?

  • 'SSL' (Secure Socket Layer).  



What is the difference between an IP address and a MAC address?

A MAC address is permanently assigned to a device on the network whereas an IP address may change when the device joins a different network



What is an IP address?

  • An IP address (Internet Protocol address) is the unique identification number given to a device connected to the internet. 
  • The IP address ist represents the unique location where you are connected to the internet