$[25$ Points, $5$ pts each$]$ Multiple choices on general concepts, select all of the statements that are correct:

a$.$ This question is about packet switching used in the internet.

i$.$ A key advantage of packet switching is statistical multiplexing of bandwidth.

ii$.$ Packet switching offers better quality of service than circuit switching. iii. Packet switching requires an end to end path to be set up in advance for

each flow.

iv$.$ Packet switching and routers do not normally maintain per flow state.

v$.$ Data packet may be lost or delivered out of order in packet networks.

b$.$ Computer Network is$.$

i$.$ Collection of hardware components and computers il$.$ Interconnected by communication channels. ili. Sharing of resources and information

iv$.$ A system designed to prevent unauthorized access.

c$.$ The internet is an example of

i$.$ Cell switched networks. ii$.$ Circuit switched networks. iii. Packet switched networks.

iv$.$ It divides networks into network classes.

d$.$ What does protocol define?

i$.$ Protocol defines what data is communicated. ii$.$ Protocol defines how data is communicated. iii. Protocol defines when data is communicated.