Q1) Explain differences and similarities between OSI model and TCP/IP model. [1 mark] Q2) What are the main functions of the data link layer? [1 mark] Q3) Name the Protocol Data Unit (PDU) for each one of these layers:[1 mark] - Data Link layer - Transport layer: - Application layer: Q4) In a TCP/IP protocol suite, four types of addresses may be needed: Physical addresses, logical addresses, port addresses and specific addresses. Write down why logical addresses and port addresses are needed. [1 mark] Q5) Illustrate with a figure the encapsulation/decapsulation procedures of a 3 layers network model. [I mark]