protocol layers and encapsulation

Question 1

what is a benefit of packet switching over circuit switching

Answer 1

packet switching allows more users to use the network

Question 2

circuit switching; fdm

Answer 2

frequency division multiplexing; optical electromagnetic frequencies are divided into frequency bands and each call/user is allocated its own band and can only transmit at its max rate

Question 3

circuit switching; tdm

Answer 3

time division multiplexing; time is divided into slots and each call is allocated periodic slots and can transmit at the max rate of the frequency band during its time slot

Question 4

bit transmission

Answer 4

enables data communication

Question 5

what are the four benefits of using the tcp/ip stack

Answer 5

structure
modularity
flexibility
extensibility

Question 6

how does the tcp/ip stack add strcuture

Answer 6

tells us how to organise functionality and interoperability

Question 7

interoperability

Answer 7

big networks are composed of different types of technology and the need to interoperate

Question 8

how does the tcp/ip stack add modularity

Answer 8

makes it easy to maintain and update the system
allows the identification and relationship of custom system pieces

Question 9

how does the tcp/ip stack add felxibility

Answer 9

you can reuse code across the network

Question 10

how does the tcp/ip stack add extensibility

Answer 10

module implementations may change

Question 11

what are the 2 benefits of the ISO model

Answer 11

allows applications to interpret the meaning of data
synchronisation check-pointing and recovery of data exchange

Question 12

what happens in the application layer

Answer 12

exchanges messages to implement some application service using services of the transport layer

Question 13

what does the transport layer do + encapsulation

Answer 13

protocol transfers from one process ot another using services from the network layer
encapsulates application layer messages with the transport layer header to create a transport layer segment

Question 14

what does the network layer do + encapsulation

Answer 14

transfers the transport layer segment from one host to another using link layer services
encapsulates transport layer segment with network layer header to create network layer datagram

Question 15

what does the link layer do + encapsulation

Answer 15

transfers the datagram from host to neighbouring host using network layer services
encapsulates network datagram with link layer header to create link layer frame