$(15\%)$ Consider Figure below. Assuming TCP Reno is the protocol experiencing the behavior shown above, answer the following questions. In all cases, you should provide a short discussion justifying your answer.

a$.$ Identify the intervals of time when TCP slow start is operating.

b$.$ Identify the intervals of timewhenTC congestion avoidance operates.

c$.$ After the $16$ th transmission round, is segment loss detected by a triple duplicate ACKor by a timeout?

d$.$ After the $22$nd transmission round, is segment loss detected by a triple duplicate ACK or by a timeout?

e$.$ What is the initial value of ssthresh at the first transmission round?

f$.$ What is the value of ssthresh at the $22$nd transmission round?

g$.$ During what transmission round is the $70$th segment sent?

h$.$ Assuming a packet loss is detected after the $26$th round by the receipt of a triple duplicate ACK, what will be the values of the congestion window size and of ssthresh?

i$.$ Suppose TCP Tahoe is used $($instead of TCP Reno$)$ and assume that triple duplicate ACKs are received at the $10$th round. What are the ssthresh and the congestion window size at the $11$th round?

j$.$ Again, suppose TCP Tahoe is used, and there is a timeout event at the $22$nd round. How many packets have been sent out from the $17$th round till the $22$nd round, inclusive?