Application layer ping

Bonus problem [20 pts]
Compare the RTT estimates from your application layer ping in Problem 1 against those of /bin/ping.
Perform tests between machines in the same lab (e.g., between pod machines in LWSN B148), and
across labs (pod machine in LWSN B148 and amber machine in HAAS G050). What results do you find?
Give your interpretation of the findings in lab2.pdf and place it under lab2/.
The Bonus Problem is completely optional. It serves to provide additional exercises to understand the
material. Bonus problems help more readily reach the 45% contributed by lab component to the course
grade.
Data Collection
We have 4 conditions that need to be tested:
1. using myping in two computers in the same lab.
2. using /bin/ping in two computers in the same lab.
3. using myping in two computers in the different labs.
4. using /bin/ping in two computers in the different labs.
For each condition, we collect the following data regarding the estimated RTT in ms.
same lab, myping same lab, /bin/ping across lab, myping across lab, /bin/ping
0.46 0.178 0.553 0.304
0.483 0.189 0.553 0.378
0.404 0.171 0.636 0.385
0.371 0.174 0.524 0.402
0.347 0.167 0.64 0.389
0.314 0.168 0.494 0.39
0.331 0.189 0.519 0.649
0.308 0.171 0.49 0.384
0.299 0.173 0.485 0.656
0.242 0.167 0.512 0.383
0.453 0.173 0.704 0.408
0.409 0.167 0.641 0.387
0.421 0.167 0.528 0.656
same lab, myping same lab, /bin/ping across lab, myping across lab, /bin/ping
0.326 0.177 0.519 0.391
0.316 0.162 0.552 0.399
0.37 0.176 0.488 0.383
0.303 0.166 0.497 0.651
0.279 0.168 0.487 0.638
0.286 0.173 0.478 0.317
0.286 0.168 0.519 0.381
Data Visualization
We visualize the collected data with a scatter chart.
Interpretation and Analysis
We can see the averages RTT (in ms) for each case are:
same lab, myping same lab, /bin/ping across lab, myping across lab, /bin/ping
0.3504 0.1722 0.54095 0.44655
From the observation and comparison, we see that in the same environment, the RTT of /bin/ping is
smaller than myping. We believe this is because /bin/ping is a system call that directly sends ICMP
ECHO_REQUEST packet. The ICMP is in the Internet Layer. On the other hand, our handcrafted myping
program, which is in the application layer, and thus the overhead is higher than /bin/ping.
Apart from that, the RTT difference ratio between myping and /bin/ping is smaller when the two
computers are in different labs.
(same lab, myping)/(same lab, /bin/ping) = 2.035
(across lab, myping)/(across lab, /bin/ping) = 1.211
We think that is because the overhead between myping and /bin/ping is fixed. However, the RTT
increases proportionally with the physical distance between two devices. Hence, we can see the
overhead impacts lower with larger spatial distance.