Topic 9 - Communication and networking - Complete Flashcards
Define serial data transmission?
Is where data is transmitted one bit at a time along a single data cable.
Define parallel data transmission?
Is where data is transmitted more than one bit at a time along separate data cables.
Define speed in terms of parallel data transmission?
If a parallel data bus had eight cables it would transmit data eight times faster than the single data cable used in a serial bus.
Define interference?
There is interference between the parallel wires which reduces the bandwidth of parallel connections, so parallel transmission bit rate is limited by interference.
Define connections?
Connection cables are short to minimise the interference effect with the parallel transmission, whereas in the serial connection there is no interference or noise problem so connecting cables can be as long as 300 feet.
Define cables?
For parallel and serial data transmission
Parallel data transmission uses more cables than serial data transmission, therefore they are larger more expensive to produce and more complex than serial cables.
Define synchronous data transmission?
Is where a block of data is transmitted along with a computer-clock-generated timing signal, this will ensure that the data transmitter and receiver are synchronised.
Define asynchronous data transmission?
Is where a data stream is not synchronised and transmitted at fixed time intervals.
Define start bit?
Used to indicate the start of a unit of data for asynchronous data transmission.
Define stop bit?
Used to indicate the end of a unit of data for asynchronous data transmission.
Define baud rate?
Is the number of symbols that are transferred across a network in a set amount of time.
Is the number of symbol changes, waveform changes, or signaling events across the network
Define bit rate?
Is the number of bits transferred across a network in a set amount of time.
Define bandwidth?
Maximum rate at which data is transferred in a given amount of time.
Define latency?
Measure the time delay between the source sending a data packet and the destination receiving the packet.
Define a protocol?
Is a set of rules or standards which computers use for communication.
Define a network topology?
Is a way of describing the interconnections and cabling of a group of computers.
Define physical topology?
Is how devices or a group of computers are physically connected.
Define logical topology?
Is how network devices communicate with each other.
Define the physical star topology?
Is based on connecting each workstation to a single point such as a hub which may also be linked to a file server.
State 2 advantages of a physical star topology?
If one of the network cables break only the computer connected to that cable is affected.
Less/ no data bus traffic.
State 2 disadvantages of a physical star topology?
If the main network cable breaks anywhere then none of the workstations can access the network.
More hardware so more expensive.
Define a client-server model?
Is where the workstations in any network design use the server to provide a service.
Define a client?
Is a computer or workstation on a typical network.
Define a file server?
Is the computer with the main processing power and storage that interacts with the clients.