3.

In frame 24, the client initiates another 3-way handshake for a connection with the

web server and subsequently issuing another HTTP GET request in frame 31.

(a)

(b)

ENG305

SINGAPORE UNIVERSITY OF SOCIAL SCIENCES (US)

(c)

Provide a screen capture of the packet list showing the frames involved in the

3-way handshake. Examine the timestamps on the frames and calculate the

Initial Round Trip Time (RTT) for the connection. [Hint: RTT is the total

elapsed time from start of a network request and receiving a response.]

(5 marks)

(d)

Frame 149 is a retransmission of an earlier frame in the file request. Provide

screen captures of the original and retransmitted frames. Highlight the relevant

packet details and explain how the original frame was identified.

(5 marks)

Page 17

Group-Based Assignment

Provide screen capture of the packet list showing the timestamps of the original

and retransmitted frames. Analyze the round-trip time (RTT) taken by the

original frame and the iRTT evaluated in Question 3(a). Compare the two

round-trip times and explain why the packet transmitted in frame 149 is indeed

a retransmission of frame 99. [Hint: a packet is retransmitted on the expiry of

the retransmission timer.]

(5 marks)

Provide screen capture of the packet list showing the timestamps of the GET

request and acknowledgement frames. Analyze the total elapsed time and data

size of the file received by the browser. Based on the analysis, estimate the

overall bit rate at which the client receives the requested file.

(5 marks)