CECS 327 Assignment 1 SOLVED

CECS 327 Introduction to Networks and Distributed Computing 
Notes:
1- This is individual assignment.
2- The assignment will be due on
3- Late assignment won’t be accepted.
Problems:
1- What advantages does a packet-switched network have over a circuit-switched
network?
2- What are the five layers in the Internet protocol stack? What are the principal
responsibilities of each of these layers?
3- How long does it take a packet of length 1500 bytes to propagate over a link of
distance 2500km, propagation speed of (2.5 x108
) m/s, and transmission rate
2Mbps? Does this delay depend on packet length? Does this delay depend on
transmission rate?
4- Suppose a 1-Gbps point-to-point link is being set up between the Earth and a new
lunar colony. The distance from the moon to the Earth is approximately 385,000
km, and data travels over the link at the speed of light—3 × 108 m/s.
a) Calculate the minimum RTT for the link.
b) Using the RTT as the delay, calculate the delay × bandwidth product for the
link.
c) What is the significance of the delay × bandwidth product computed in (b)?
d) A camera on the lunar base takes pictures of the Earth and saves them in
digital format to disk. Suppose Mission Control on Earth wishes to
download the most current image, which is 25 MB. What is the minimum
amount of time that will elapse between when the request for the data
goes out and the transfer is finished?
Hands-on Activities:
Use Networking Tools:
5- Measuring Round Trip Times with Ping: In Windows, open a command prompt. Use
the -? Flag on the ping command and find out a list of options available for the ping
command. (Support your answers with screenshots)
a. Try a simple ping www.google.com. Record the minimum, maximum and
average round trip times.
b. Try the option ping –n 2 www.google.com. And then try ping –n 7
www.google.com. What differences do you notice?
c. Try ping 10.0.0.50 and write down what output you get and explain why you
get the result.
d. Try ping www.imperialequestriancenter.com Did you receive any responses
for the packets you sent? What are some reasons as to why you might have
not got a response?
6- Understanding Internet routes using Traceroute: In Windows, open a command
prompt. Use the -? Flag on the tracert command and find out a list of options for the
tracert command. (Support your answers with screenshots)
a. Try a simple tracert www.google.com. How many hops there were between your
computer and www.google.com?
b. Compare tracert www.google.com and tracert www.ieee.org. What hops are the
same for each destination?
c. Try tracert www.ubc.ca and then try the option tracert –d www.ubc.ca. What
differences do you notice?
d. Compare round trip times to the number of hops from a local host to the three
hosts, www.tsinghua.edu.cn, www.usyd.edu.au and www.harvard.edu at different
times of a day (e.g, morning, afternoon and evening). What correlation(s) do you
find? Are these your expectations? Explain.
e. Run traceroute on your local machine for the previous URLs, then paste the output
in the following link. What do you conclude? Include a screenshot in your response.
https://stefansundin.github.io/traceroute-mapper