a) How OSI layers play their role in the communication between two computers. Illustrate the role of each layer with example b) Explain how the collisions occur in hubs and what can be done to make a collision free environment. Question #4 [05 Marks] a) In the below topology explain the situation when i. ii. B III. 0260.8c01.1111 0260.8c01.4444 Computer A sends a frame to computer B assuming Switch 1 has not learned the MAC address of computer B yet. How switch 1 and switch 2 will react. Switch 1 has learned both MAC addresses. Now if computer A sends a message to computer B, what will the switch 2 do with the frame? If we are using UTP cables to connect devices in the below network topology, label the diagram with the correct cable type (straight or cross over) E1 EO Switch 1 E2 EO E1 Switch 2 Question #5 [05 Marks] In the network topology shown in Question # 4, how a network administrator can provide redundancy between switches? What would be the sudden impact on the network right after the redundancy is provided. Discuss all possible issues in detail and also the solution to each problem.