Fundamentals of networking Flashcards
Three different transmission modes and what they consist of
Simplex connection: data flows in one direction from transmitter to receiver
Half-duplex: data can flow in one direction or the other but not both at the same time
Full-duplex: data can be transferred in two directions at the same time
Two different methods of data transmission and what they consist of
Serial data transmission: bits are sent one by one over a single wire (by varying the voltage on the wire, which represents either a 0 or 1) from source to destination
Parallel data transmission: several bits are sent simultaneously over different parallel wires. Is only reliable over short distances, as skews can take place
Advantages of serial over parallel
- Reduction in complexity of connectors results in lower costs
- Crosstalk creates interference over parallel lines, can result in corrupted data
- More reliable over greater distances
Define synchronous and asynchronous data transmission
Synchronous: a form of serial communication in which the communicating endpoints’ interfaces are continuously synchronised by a common clock
Asynchronous: data is transferred without support from an external clock signal. Uses start and stop bits to indicate beginning and end of transmission, and when one bit ends and another begins.
What is a parity bit?
A bit which is sent in order to check for errors
Define latency
Latency is the time delay between the moment that transmission of the first byte or packet of a communication starts and when it is received at its destination
Define ping
Sending a signal from one computer to another
Define bit rate
The speed at which data is transmitted serially is measured in bits per second
Define baud rate
The maximum rate at which signals on a wire or line may change
What is the equation used to work out bit rate?
Baud rate x number of bits per second
Define bandwidth
Bandwidth is the range of frequencies that a transmission medium can carry. Measured in hertz.
Relationship between bandwidth and bit rate
The greater the bandwidth of the transmission system, the higher the bit rate that can be transmitted over that system
What is a bus topology in the concept of networking?
A network where all computers are connected to a single cable
Advantages and disadvantages of bus topology
- Simple and cheap to install
- If one node fails, the entire network still can operate
- If main bus cable fails, entire network fails
- Performance of the network slows down rapidly with more nodes or heavy network traffic
- Low security as all computers on the network can see all data transmissions
What is a star topology in the concept of networking?
A star network is a network structure which has a central node, may be a switch or computer which acts as a router to transmit messages.
