Network Analysis Assignment
Measuring bandwidth, delay and jitter
1 Introduction
The aim of this project is for you to gain practical experience in making measurements in
networks and working with common networking command line utilities. You will specifically
be involved with the measurement of bandwidth, delay and jitter. These tasks will be similar to
those you have performed in the laboratory sessions held in the tutorials. It is recommended that
you perform. these tasks in a consistent networking environment to reduce the variance in your
results.
Important Note: When you run these commands, take a screenshot of the results obtained
and place it in the appendix of the document. Reports failing to do so will be penalized. All
plots however, should be placed in the main body of your report where you will explain the
observations being derived.
2 Measuring the hop count
In this section, we will be observing the number of intermediate hosts in the route taken to
communicate with a remote server and its relation to the physical geographical distance.
To count the number of hops taken to reach a destination host, the command tracert
will be used (or its corresponding equivalent, depending on your operating system). This utility
should be pre-installed on your operating system.
The utility can be invoked by launching a command line terminal and typing in the command.
An example output of the traceroute command (on OS X) and tracert command (on
Windows) is as follows:
$ traceroute -nw1 cis.unimelb.edu.au
traceroute to cis.unimelb.edu.au (128.250.37.164), 64 hops max, 52
byte packets
1 10.0.0.254 533.676 ms 1.063 ms 0.940 ms
2 58.96.2.205 27.872 ms 28.137 ms 28.293 ms
3 58.96.2.129 28.647 ms 28.577 ms 28.085 ms
4 218.100.78.33 28.299 ms 28.469 ms 28.332 ms
5 202.158.200.9 29.626 ms 28.871 ms 29.841 ms
6 202.158.210.26 31.320 ms 28.722 ms 29.135 ms
7 202.158.200.250 29.668 ms 29.096 ms 28.660 ms
8 * * *
9 * * *
10 * * *
11 128.250.37.130 957.521 ms 33.475 ms 29.891 ms
12 128.250.37.164 29.940 ms 29.260 ms 30.020 ms
In this section of the project, you are interested in the number of hops it takes to reach the
destination server. In the example above, the number of hops to reach cis.unimelb.edu.au is 12.
1
Based on the number of measurements you will be taking, there are some useful command
line parameters you may wish to take advantage of, to speed up the time it takes to gather
results. The help documentation for the traceroute utility can be accessed by running man
traceroute or tracert /? on Windows. You may also wish to investigate shell scripting
to automate the collection of results, but this is not required for the project. Any scripts you do
choose to write, however, must be included in the Appendix.
2.1 Task description (1.5 marks)
Please include all raw measurements in the Appendix.
2.1 What do the command line parameters -nw1 (equivalently -d -w 1 on Windows) mean
in the example given above and why were they used?
2.2 Determine the hop count for the following hosts given in Table 1.
Table 1: List of public iperf hosts
Host Location
iperf.he.net USA
bouygues.testdebit.info France
iperf.comneonext.de Germany
ikoula.testdebit.info France
st2.nn.ertelecom.ru Russia
iperf.biznetnetworks.com Indonesia
iperf.scottlinux.com USA
speedtest.serverius.net Netherlands
Determine the approximate geographical distance for the above hosts and plot the hop
count versus the approximate geographical distance from Melbourne. Do you observe a
correlation? Why? Why not?
You may use any scientific computing package or spreadsheet software to do your plotting,
for example, Microsoft Excel .
Note: These servers are public servers and are not maintained by the University of
Melbourne, hence they are likely to go down at any point in time. Based on past experience,
it would be advisable to conduct your tests on these as soon as possible (ASAP) rather
than leave it till the end of the time frame. because there is a high probability that these
servers might not be available then (no longer work). If these servers stop responding then
please visit the link: https://iperf.fr/iperf-servers.php and find your own servers (anything
that is responding) or feel free to find any public iperf server from the internet, including
deploying your own iperf server.
3 Measuring delay and jitter
In this section, you will be measuring the delay and jitter of different hosts located in different
geographical locations.
We will be using the ping utility, to measure the round-trip delay of packets. The ping
utility should be pre-installed on all major operating systems. The standard deviation of the
round-trip delay time will be taken as the value for jitter for this project.
The standard deviation measures the variation in a set of data. It is defined as the square root
of the variance and is expressed as follows :
=
vu
ut 1
N 1
NX
i=1
(xi x)2
2
where x is the mean of the set of data.
A sample output of the ping utility is shown below, but this output will vary depending on
your operating system.
$ ping unimelb.edu.au
PING unimelb.edu.au (172.22.44.10): 56 data bytes
64 bytes from 172.22.44.10: icmp_seq=0 ttl=124 time=3.364 ms
64 bytes from 172.22.44.10: icmp_seq=1 ttl=124 time=3.416 ms
64 bytes from 172.22.44.10: icmp_seq=2 ttl=124 time=3.730 ms
ˆC
--- unimelb.edu.au ping statistics ---
3 packets transmitted, 3 packets received, 0.0% packet loss
round-trip min/avg/max/stddev = 3.364/3.503/3.730/0.162 ms
In the output above, various statistics, including the mean and standard deviation, were
calculated for you by the utility. It is expected that you record all the values of delay and perform
your own calculations to find the mean values and their standard deviation, to confirm the result.
3.1 Task description (3 marks)
Please include all raw measurements in the Appendix.
3.1 What are the user-facing implications of high delay and high jitter in networking appli-
cations? Give specific examples on applications that are sensitive to both high delay and
high jitter. Why is this the case?
3.2 Measure the round-trip delay for the following hosts. Make three delay measurements
(run this command 3 times) of each host and find the average round-trip delay and jitter by
calculating the standard deviation, for each host in Table 1.
For each of the above hosts, plot the average round-trip delay versus the approximate
physical geographical distance to the server. Do the same with the jitter.
For finding out the physical grographical distance you may use any tool or applica-
tion available online, for example, you may use a combination of: https://db-ip.com and
https://www.freemaptools.com/how-far-is-it-between.htm or https://www.site24x7.com/find-
website-location.html and https://www.distancecalculator.net/ or anything of your choice.
However, do make sure to document it and provide the appropriate reference to that
application/ tool/ software used.
3.3 From the two plots above, do you observe any correlation between delay and jitter as a
function of distance? Why? Why not? Explain your results with reference to the network
environment in which you were collecting your results.
4 Measuring the bandwidth-delay product
In this section, we will be measuring the bandwidth of different hosts in order to determine the
bandwidth-delay product, using the results from the previous sections.
The utility that will be used to perform. bandwidth measurements will be the iperf utility.
This command line utility is available for download for all operating systems from https://iperf.fr.
Alternatively you may choose to use the package manager for your relevant operating system.
There are two modes of operation in iperf. The server mode will host a server which
will listen to incoming requests from a client. An iperf instance running in client mode will
connect to the server, and packets will be exchanged and timed between the two hosts to calculate
the bandwidth. In this project, we will be running iperf in client mode.
A sample output of iperf in client mode is shown below, noting the -c flag to designate
operating in client mode.
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$ iperf -c iperf.eenet.ee
------------------------------------------------------------
Client connecting to iperf.eenet.ee, TCP port 5001
TCP window size: 129 KByte (default)
------------------------------------------------------------
[ 5] local 10.0.0.5 port 51878 connected with 193.40.100.7 port 5001
[ ID] Interval Transfer Bandwidth
[ 5] 0.0-106.7 sec 128 KBytes 9.83 Kbits/sec
(Note: speedtest.serverius.net server) For speedtest.serverius.net, we need to use the port
5002, so the command will be: ”iperf3 -c speedtest.serverius.net -p 5002” for this host. Also,
some iperf servers respond to iperf2, rest to iperf3 so you might want to use both iperf2 and
iperf3 to verify if the server is responsive.
4.1 Task description (5.5 marks)
Please include all raw measurements in the Appendix.
4.1 What does the bandwidth-delay product tell us about the networks. Give specific examples
of networks with high bandwidth-delay products. How is the bandwidth-delay product
used in relation to throughput efficiency?
4.2 Collect three set of measurements (run this command 3 times) measuring the bandwidth
of the public iperf hosts in Table 1 and find the mean bandwidth for each host.
4.3 Take the mean bandwidth and calculate the bandwidth-delay product in kilobits. You may
use the mean round-trip delay time from your ping experiments to use as the delay time.
Plot a bar chart for each host showing your results. You may wish to use a logarithmic
scale, if appropriate.
Explain your results making reference to your networking environment which you per-
formed your measurements. How do your results reflect upon your actual internet link
speed? Are there outliers in your data?
4.4 Plot the bandwidth-delay product versus the hop count, this time omitting any outliers. Is
there any correlation? If not, why not?
4.5 For each of the three sections in the project, give a brief description on your methodology,
including all commands invoked, plotting software and operating system used, networking
conditions and bandwidth of your internet link that will allow others to analyse your results.
Were there any variables which may affected the accuracy or reliability of your results?
How might you improve upon these?
Reflect on the ease/difficulty on collecting accurate information in networks, in general.
What are some aspects that hinder or assist this process?
5 Administration
This project can be performed individually or in pairs (2 people max) and is worth 10% of your
overall mark in the subject. We will issue further information regarding groupwork in the weeks
to come, including the submission of an individual reflection report.
5.1 Getting help
If you have any questions, the LMS discussion board will be a useful resource in resolving any
issues. If your concern is a personal matter, then you should email the subject coordinator.
Any answers posted by the subject coordinator or the academic staff on the LMS discussion
board will be considered as part of the project specification. Any announcements made about the
assignment in the lectures will be considered part of the project specification. In addition, please
keep an eye on any LMS announcements to any changes made to the project specification.
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5.2 Academic honesty
Turnitin will be used as a deterrent against academic dishonesty. All gathered results, plots
and discussion must be your own original work. All other information must be cited in an
academically recognised style.
Plagiarism and collusion constitutes cheating. Disciplinary action will be taken against
students who engage in plagiarism and collusion in accordance with university statute 13.1.18.
For examples and more information on what constitutes plagiarism and collusion, please visit
http://academichonesty.unimelb.edu.au.
5.3 Report submission
The deadline for the final report submission is as specified at the start of this project document.
The report will consist of all relevant discussion, graphs, data and answers from the experi-
mentation conducted in this project. You must place the raw data as screens or copy paste them
to the Appendix of the document, however, the diagrams like charts, flow diagrams (if any) and
so on relevant to the discussion will be placed in the main document and not the appendix. Every
diagram and/or raw measure used for a specific question must be referred to for us to verify the
result. All plots and figures must be appropriately labelled. Any information obtained that is not
of your own work must be cited.
The report must be submitted as a PDF file via Turnitin on the LMS. Please include as the
first page, a cover sheet containing your name and login user name. The report is to be formatted
on A4 sized paper in 10 pt text, 1.5 line spacing and a minimum 3.8 cm margins on the left and
right sides.