Network Flashcards
Define Topology
Structure of a network
What are the two types of topologies
Physical and Logical
What does physical topology refer to
The actual architecture of a network
What are the two types of physical network topology
Star and Bus
Describe a Physical Star Network Topology
A central hub is connected to each device by a unique wire
Advantages to a physical star network
Packets are sent directly to their recipient through the unique cable - increases privacy
Easy to add and remove clients to and from the network
Each cable has just one device communicating over it - eliminating the possibility of collisions
Failure of one cable does not affect the performance of the rest of the network
Disadvantages to a physical star network
All communications would fail if the central hub fail
Expensive to install thanks to the amount of cable requires
What is a logical topology
The flow of data packets within a network
How can a physical star network act like a logical bus network
If there is a bus protocol running it
What is a host device network
A device that provides services on a network
Describe a Client Server Network
One or more central servers provide services to the clients on the network
Servers are connected to the same way as clients
Clients on the network request services from the servers
Who uses Client Server networking and why
Most schools, colleges and businesses
Allows for central management of clients on the network
Describe a Peer to Peer network
Clients provide services themselves
Every client has equal status
Disadvantages to a Peer to Peer network
All clients which provide services must be running in order for it to be fully functional
Advantages to a peer to peer network
More cost effective as they dont have to pay for a server
Easier to set up and maintain then other networks
Who uses peer to peer networks
Large file sharing networks and multimedia providers
What do Wireless networks require
A WAP which connects to a wired netowrk
A Wireless Network Adapter in the device that connects to the wireless networks
What do wireless networks allow
Clients to communicate within a network without being physically connected to it
What is WiFi
A wireless LAN based on international standards
How are wireless networks secured
By encrypting transmitted data using WPA or WPA2
WPA stands for WiFi Protected Access
Disabling SSID Broadcast
MAC Address Filter
How do WPAs work
They require any new wireless clients to enter a password in order to connect to the network
What is a SSID broadcast and what does disabling it do
SSID stands for service set identifier - name that identifies a wireless network
Disabling SSID broadcast stops wireless devices within range of the network from displaying that the network is available
Only those who know the SSID can connect
What does MAC stand for
Media Access Control
How does setting up a MAC Address Filter improve network security
Only whitelist MAC Addresses can connect to a network
What does CSMA/CA stand for
Carrier Sense Multiple Access with Collision Avoidance
What is CSMA/CA
A protocol used in wireless networks to avoid data collisions caused by multiple devices communicating simultaneously
Describe the CSMA/CA flowchart
Start -> Channel Idle?
YES -> Transmit -> End
NO -> Wait -> Start
How does CSMA/CA work
When a device is ready to transmit, it listens to its communication channel to check whether it is idle
If it is idle - data is transmitted
If not - device waits for a random amount of time
Problems with CSMA/CA
Cannot overcome hidden nodes
How does CSMA/CA get around hidden nodes
Request to Send/ Clear to Send
RTS/CTS
How does RTS/CTS work and why
Adds an additional step into the CSMA/CA process
Once it checks if channel is idle - it sends a request to send message to the server
If it is idle - It will send a CTS message
If it is busy - No CTS message is received and it repeats the CSMA process
