Chapter 9 Communications and Networking Flashcards
What does bus topology look like
a central cable which terminates at each end with various devices attached to it
What does star topology look like?
A central switch which all the devices are connected to
Positives of star topology
High connection speed
Fewer collisions occur
Positives of Bus topology
Cheaper
Easier to add new devices
Negatives of bus topology
Collisions more likely
If bus cable breaks whole network fails
Less secure
Negatives of star topology
Expensive cabling costs
If central device fails, the whole network fails
What does a Network Interface Card (NIC) do?
It contains a MAC address used to uniquely identify the device
What does a switch do
directs packets of data to the correct recipient (using their mac address)
What hardware is needed to connect devices to a wired network
Network Interface Card (NIC)
Switch
What hardware is needed to connect devices to a wireless network?
Wireless Network Interface Card
Wireless access point
Which is more secure wired or wireless networks?
Wired
What are 3 ways you can improve your wireless security
Hide the SSID
Use strong encryption
Use Mac Address “Allow Listing”
What is data transmission?
The movement of data from one place to another.
What is Serial data transmission
single bits are sent along one wire one bit at a time
What is parallel data transmission?
Multiple bits are sent down several wires simultaneously
Which is faster serial or parallel data transmission?
Parallel
Which is cheaper serial or parallel data transmission?
Serial
Which can experience cross talking, serial or parallel data transmission?
Parallel
Which is more suited to longer distances serial or parallel data transmission?
Serial
How do you calculate the bit rate?
Baud rate x Bits per signal
WHat is bit rate?
The number of bits transported per second
What is baud rate?
The rate at which signal on a wire may change
What is band width
The range of frequencies that data can be transmitted, measured in hertz
What is latency?
The delay between data being sent and recieved
When is synchrous data transmission used?
When it is devices sharing the same system clock communicating
When is asynchronous data transmission used?
When the 2 devices don’t share the same clock
How does asynchronous data transmission work?
The 2 devices get temporarily synchronized
A start bit starts the receiver clock ticking to synchronize with the transmitter clock
A stop bit provides time for the receiver to process the received data and allows next start bit to be recognized.
