If there is a flow that is only one direction in our file (this was found in top 3 duration), then should we take this flow into account as it would give us empty graphs for RTT portions of this assignment. There is no SYN/FIN/RST packets, and all of these ACK packets are Len=0, so I think we can assume that any data transferred or any connection establishment or finish is before and after the file.
the flow looks like this:
56182 > 5900 [ACK] Seq=1 Ack=126 Win=65535 Len=0 TSval=763111061 TSecr=2134609349
56182 > 5900 [ACK] Seq=1 Ack=449 Win=65535 Len=0 TSval=763111064 TSecr=2134609350
56182 > 5900 [ACK] Seq=1 Ack=1017 Win=65535 Len=0 TSval=763111065 TSecr=2134609350
if the source ports are placed into a set, it would be 1 number, likewise for destination ports.