CSCI 4171 Networks and Communications-Assignment NO. 1

• 作业标题：CSCI 4171/CSCI 6704： ASSIGNMENT NO. 5
• 课程名称：Dalhouse University CSCI 4171 Networks and Communications
• 完成周期：1天

Write the answers to the questions in a word or similar text-based document, convert the document to PDF and submit ONE PDF file on Brightspace. On top of the document, clearly write your full name and Banner ID.

Question 1

Question 1 <Virtual Circuit Packet Switching >
Consider the following network that uses virtual circuit packet switching

Figure source: https://www.grotto-networking.com/BBMPLS.html
The following virtual circuit paths need to be set up:

Host A to Host J via Switch #2
Host B to Host H via Switch #2 and #5
Host C to Host E via Switch #1
Host D to Host H via Switch #5
Host F to Host I via Switch #4
Host E to Host B via Switch #4, #5 and #2
Host G to Host D via Switch #5
Host H to Host C via Switch #3 and #1
Host I to Host F via Switch #4
Host J to Host A via Switch #2

Using appropriate virtual circuit identifiers, set up the virtual circuit paths and draw the virtual circuit tables in each of the switches #1 to #5 when all the paths are simultaneously active.
You must choose the virtual circuit identifier as follows. On any link in a particular direction, start with the number 10. If 10 cannot be used, use 20. If 10 and 20 cannot be used, use 30, and so on. This will ensure that you will use a different number only if necessary

。。。

Question 2

Question 2: <TCP/IP Encapsulation Discovery using Wireshark>
As you would know from your previous course in networking, Wireshark is an excellent tool for packet capture
and studying the components of different parts of a message. For this question, you will perform a simple
packet capture using Wireshark to identify different headers.

a) If you don’t have Wireshark installed on your machine, download Wireshark
https://www.wireshark.org/download.html
and understand its features, including how to set the display filters.

b) Clear your browser cache and open a browser window.

c) Start Wireshark capture.

d) Enter http://gaia.cs.umass.edu/wireshark-labs/HTTP-wireshark-file2.html in the browser window.
(This is an HTTP site from the book “Computer Networking: A Top-Down Approach” by Kurose and Ross.
It contains a simple HTML file).

e) After a few seconds, close the browser window.

f) Stop Wireshark capture.

g) Set the display filter to HTTP.

h) Select one HTTP message and click on various parts of the message, namely, Application Layer, Transport
layer, Network Layer and Data Link Layer, thus identifying the TCP segment, the IP datagram and the
Ethernet header.

i) Examine the above and identify all the header components (in decimal or Hex as appropriate) for the
TCP header, the IP header and the Ethernet header.
For the TCP Header, identify as many fields as you can using the figure shown below as a guide. Write
their values from your Wireshark capture.

。。。。