Tprop be one-way propagation delay,
Ttrans be transmission time of one 2500 byte packet,
Tprop = 30 ms
Ttrans = (2500 bytes * 8bits/byte)/(10^6 bits/second) = 10 ms
T3-way handshake = 3 * Tprop = 90ms
Size of application data in a TCP packet = size of TCP segment – size of header = 2450 bytes.
Number of packets needed to transfer a 60 KB file = (60*1000)/2450 = 25
Hence, the window size grows as 1, 2, 4, 8, 10
Hence, the total time to transfer the packet after the 3-way handshake is:
Tdata = 25 packets transmission time + 5 * 2*propagation time
= 25 * 10 ms + 300 ms
= 250 ms + 300 ms
= 550 ms
Hence, total time to transfer = T3-way-handshake + Tdata = 90 ms + Tdata ms = 640 ms