3. 10 points]: TCP reliable data transfer protocol (a) The sender sends two packets, one with 15 bytes of data and the other with 30 bytes of data. The initial sequence number is 37 and the first packet is lost when it is first sent Draw a timeline showing the sequence of events in this scenario (b) Suppose two TCP connections A and B traverse a common bottleneck link of capacity R bps. Using a diagram, explain how TCP congestion control achieves fair allocation of the bottleneck bandwidth to the two connections 3 2 3 4 Figure 1: Network for Problem 4(b) 4 [10 points): Link-state routing and Dijkstra's algorithm (a) In the nth step of Dijkstra's algorithm, what key property does the node that is added to the set of "permanent" nodes, N', possess? Explain how the algorithm maintains this property for the node that is added in the next, i.e., the (n +1)st, step (b) Apply Dijkstra's algorithm to obtain the routing table for node a in the network given in Figure 1