(a) Describe briefly the packetizing services provided by network-layer of the TCP/IP (3 marks) (b) Describe briefly the multiplexing services provided by the network-layer of the protocol suite. TCP/IP protocol suite. How can the multiplexed TCP and UDP packets be (4 marks) (c) Describe briefly the impact of congestion on packet delay and throughput. Describe (6 marks) (d) Fig. Q1 shows a network adopting the virtual-circuit approach to transmit demultiplexed at the destination? the strategy used in the Internet to reduce its impact. datagrams. Suppose that a virtual circuit has been setup between host A and host B via R1, R3 and R4 i. Describe how the forwarding table was setup at R1, R3 and R4 (8 marks) ii. Describe the forwarding process when host A sends datagram to host B (4 marks) A to B Incoming Outgoing Pon Labe Por Label 1 14 RI 2 R2 R5 R3 R4 Incoming Oulgoing Port Label Por Label 1 22 4 77 A to B