QUESTION

a) Security is a very crucial component in a Distributed System. Describe three properties of a secure channel.

b) During packet transmission, messages are subdivided into packets. Give two reasons why restricted length of packets are used.

c) Differentiate between Packet and Circuit Switching.

d) Explain the term "Virtual Circuit Packet Delivery".

e) The Network Time Protocol service can be used to synchronize computer clocks. Explain why, even with this service, no guaranteed bound given for the difference between two clocks.

QUESTION

a) Give three UDP features and three TCP features.

b) Give three main sources of overhead.

c) Is it conceivably useful for a port to have several receivers?

d) Define the semantics for and design a protocol for a group form of request reply interaction, for example using IP multicast.