For the shown topology, assume that distances are less than 100 meters long. PRA FC PORO J 09: 00:00: PORN It is required to exchange messages between the eight PC's A, B, C, D, E, F, G, and H. For that purpose, the following FOUR scenarios werd posed: Scenario 1 Each PC is connected via al link to a box that performs circuit-switching. Scenario 2 Each PC is connected via al link to a box that performs packet-switching at layer 1 (Physical Layer). Scenario 3 Each PC is connected via al link to a box that performs packet-switching at layer 2 (Data Link Layer). Scenario 4 Each PC is connected via al link to a box that performs packet-switching at layer 3 (Network Layer). For each of the FOUR scenarios: a) Draw a detailed network diagram showing ALL components (hardware and software) needed to allow meaningful communication between (A and D). (B and E), (C and F), and (G and H). b) Draw the format of the message (or its components) as it travels between one source and the corresponding destination. c) Explain the mechanism by which a message in a source PC is delivered to the appropriate destination PC. d) State the factors that determine the delay between the time a message is ready to send at the source, and the time it is completely delivered to the destination. Hence, write a mathematical expression for the delay. e) Determine the link speeds of the PC's and the switching speed of the switching box, if the message is produced in the form of bursts, with the following characteristics: average burst duration - 40 ms, average burst size=1280 bits, and average interval between bursts - 60 ms f) Compute the maximum throughput through the switch for the values given in e) above. Under what conditions is the maximum throughput realized?