Suppose TCP uses AIMD for its congestion control without slow start. Assuming cwnd increases by 1 MSS every time a batch of ACKs is received and assuming approximately constant round-trip times, how long does it take for cwnd increase from 6 MSS to 12 MSS (assuming no loss events)? b. What is the average throughput (in terms of MSS and RTT) for this con-ection up through time = 6 RTT?

The answer is "6 RTT and  "

Explanation:

TCP uses AIMD without a sluggish start for congestion control.  

Sliding windows original = 4 MSS  

Every RTT is increased by 1 MSS throughout the congestion window(cwnd).  

In (a):  

Its City is rising between 6 and 12 MSS  

Each RTT cwnd window increases by 1 MSS  

We can see that 6 RTTs from 12 MSS city sizes, so it takes time to achieve 6 MSSs = 6 RTT  

In (b):

Time = 6 RTT

Each RTT cwnd window will up by 1 MSS  

Window Size Original = 4 MSS

It is possible to view the window after 6 RTT (cwnd) = 10 MSS  

i do not get the question.