Given Go-Back-N protocol scenario in the following figure, describe what would happen for each of the numbered time instants, (1) through (5). Assume the senders window size may hold 6 packets, and there are always enough number of packets to be sent from the sender this means the window slots will never be left idle. Also, assume that there are many packets waiting to be transmitted by the sender (i.e., packet6, packet7, ...). X marked packet transmissions denote lost packets.

(a) What actions would be taken at time instant (1)? (b) What actions would be taken at time instant (2)? (c) What action would be taken at time instant (3)? (d) What action would be taken at time instant (4)