Select an arbitrary ACK packet in ethereal sent by PC2 to PC1. Locate the acknowledgement number in the TCP header. Now relate this ACK to a segment sent by PC1. Identify this segment in the ethereal output. How long did it take from the transmission of the segment, until the ACK arrives as PC1?

What will be an ideal response?

Frame 24 has the acknowledgement number 339283589 sent by PC2. This frame is to
acknowledge Frame 16. The transmission takes 0.006669 (0.015096 - 0.008427) second. So it takes around 6.7ms from the transmission of the segment until the ACK arrives at PC1.
```
15 0.008416 10.0.5.11 10.0.5.22 TCP 3117 > 4444

[ACK] Seq=339282141 Ack=305997828 Win=5840 Len=1448

16 0.008427 10.0.5.11 10.0.5.22 TCP 3117 > 4444

[ACK] Seq=339283589 Ack=305997828 Win=5840 Len=1448

17 0.008407 10.0.5.22 10.0.5.11 TCP 4444 > 3117
[ACK] Seq=305997828 Ack=339279245 Win=14480 Len=0

18 0.008446 10.0.5.11 10.0.5.22 TCP 3117 > 4444

[PSH, ACK] Seq=339285037 Ack=305997828 Win=5840 Len=1448

19 0.008491 10.0.5.22 10.0.5.11 TCP 4444 > 3117

[ACK] Seq=305997828 Ack=339280693 Win=17376 Len=0

20 0.008576 10.0.5.22 10.0.5.11 TCP 4444 > 3117

[ACK] Seq=305997828 Ack=339282141 Win=20272 Len=0

21 0.008936 10.0.5.11 10.0.5.22 TCP 3117 > 4444

[PSH, ACK] Seq=339286485 Ack=305997828 Win=5840 Len=864

22 0.009003 10.0.5.11 10.0.5.22 TCP 3117 > 4444

[PSH, ACK] Seq=339287349 Ack=305997828 Win=5840 Len=1000

23 0.009054 10.0.5.11 10.0.5.22 TCP 3117 > 4444

[PSH, ACK] Seq=339288349 Ack=305997828 Win=5840 Len=1000

24 0.015096 10.0.5.22 10.0.5.11 TCP 4444 > 3117

[ACK] Seq=305997828 Ack=339283589 Win=23168 Len=0

25 0.015182 10.0.5.11 10.0.5.22 TCP 3117 > 4444

[ACK] Seq=339289349 Ack=305997828 Win=5840 Len=1448
```