Networking Flashcards
What is a bus topology
Has one cable that connects every device on the network called the backbone
At each end theres a small device called a terminator, absorbs signals when they reach the end to prevent interference
Each device connected to main cable
How does a collision in a bus topology occur
If 2 or more devices try to sent data at the same time, causing signals to interfere
If collision occurs, devices must wait a random amount of time before trying again
How strong is the security on a bus topology
Weak ass unless data is encrypted, every device attached to the bus can read every message sent to their device
Comment on the reliability of a bus topology
If the main cable fails, the whole network will stop.
If theres is a failure in a cable that connects a single device, it will affect only this device
Difference between a logical and physical topology
Physical topology:
- depicts physical layout
- physical connection of network
- actual route of transmission
Logical topology:
- logistics of network of data transmission
- data path followed of the network
- high level representation of data flow
What is a star topology
Each device is connected to central communication device (hub or switch)
How strong is the security on a star topology
High as messages are transmitted on a specific path (source to destination)
Comment on the reliability of a star topology
If the switch or hub fails, no connected device will be able to communicate
If an individual cable fails only that device will be affected and the rest of the network can continue to operateb
What is a client-server network
One or more central servers that provide services to clients of the network
What is a peer-to-peer network
A network where there are no central servers, but rather the devices on the network provide the services themselves
Advantages of Client-server networks
- servers can be located in secure rooms
- management of network can be done from one location to another
- files can be ordered easily
- more powerful machines that their clients
Advantages of peer-to-peer networks
- cheap to setup as no specialist equipment required
- easier to setup and maintain than client-server
What is WPA2
An improvement on WPA as it provides an even stronger encryption algorithm
Why do we use WPA2 over WPA
provides an even stronger encryption algorithm by encrypting each message several times depending on the key size
What is an SSID
A string of alphanumeric characters that’s specified during the setup of wireless devices
How can you make SSID’s more secure
You can hide them from being broadcasted, so to join the network you would need to know the exact SSID and enter it
What is a WLAN
A wireless local area network, based around central communication devices called wireless access points
What is the frequency band and name the 2 most common ones
A specific range of radio wave frequencies
Most common are 2.4GHz and 5GHz
What is 2.4GHz used for
General industrial use
What are Channels
They are smaller bands within the frequencies
A network will be configured to operate on a specific channel
Describe CSMA/CA without RTS/CTS
- Assemble a new frame
- Check if channel is idle
- If it is empty the data is transmitted
- If not then the device will wait a random period of time
What is an issue with CSMA/CA
It cannot overcome hidden nodes as it cannot see some parts of a network where communication may be occurring
Describe CSMA/CA with RTS/CTS
- Assemble a new frame
- Check if channel is idle
- If idle, send a RTS message
- If CTS message is received, transmit data