Consider the congestion window size vs$.$ RTT diagram below. Assume the Reno protocol is used.

Answer the following questions. In all cases, you should provide a short discussion justifying your

answers.

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

b$.$ How many MSSes were sent at the $10$th transmission round?

c$.$ If the first loss event occurs after the $35$th transmission rounds, how many MSSes are

transmitted at the $13$ transmission round?

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

e$.$ Identify all the intervals of time when TCP congestion avoidance is operating.

f$.$ Identify all the intervals of time when TCP fast recovery is operating.

g$.$ State, if any, the loss event at: ${10}^{th},13rd,17nd,24nd$ transmission round.$($individually$)$

h$.$ What is the value of ssthresh at the $16$th transmission round?

i$.$ What is the value of ssthresh at the $25$ th transmission round?

j$.$ At and include transmission round $4,$ how many MSS segments have been transmitted?

k$.$ At and include transmission round $7,$ how many MSS segments have been transmitted?

I. During what transmission round IS the $120$th segment sent? Hint: Make use the result in $4.$n$.$

$m.$ Assume a timeout event is detected at the $9$th transmission round, what is the values of

ssthresh and cwnd at the ${10}^{th}$ transmission round.

n$.$ Assume a triple duplicate ACK event is detected at the oth transmission round, what is the

values of ssthresh and cwnd at the $10$th transmission round.

o$.$ Under the TCP congestion control, is it possible that the TCP connection sending rate can

reach the sending host's physical link speed.

p$.$ Refer to $4.$r$,$ if your answer is $"$no$",$ explain in one or two sentences why it is not possible to

reach the link speed. But if your answer is "yes", state which phases $($slow$-$start, congestion

avoidance, or fast recovery$),$ this could happen?

q$.$ Is the ssthresh is useful when the TCP congestion control is in the fast recovery phase?

Justify your answer.