Reference no: EM133919796

Introduction to computer systems, networks and security

Assignment - Networks

Purpose: In this assignment, students will record data from a real-world wireless network and demonstrate that they can analyse it, identify its properties and potential issues. Also, students will analyse Internet traffic and identify servers, clients and protocols used.

Part 1: Reflection

Complete your reflection activities for Week 7 to Week 9 in the corresponding Ed Lesson and copy/paste them into a PDF file. Write at least 100 words for each week (relevant and meaningful to the specific week). Get expert-level assignment help in any subject.

Part 2: WLAN Network Design and Security
For this part of the assignment, you will perform a real-world WLAN site survey. Your task is to produce a map of part of a building that gives an overview of the wireless networks that are available, as well as an analysis of the network.

What you will need: a WiFi-enabled laptop (some smartphones also work, see below), and a place to scan. You have to perform a survey of parts of the Monash Clayton / Kuala Lumpur campus.

Task 2.1: Survey

Draw a floor plan with details

A simple floor plan will be sufficient. It does not have to be perfectly to scale. See Appendix A for an example. The map should be labelled with all relevant information (e.g., dimension, door, wall and material such as wood or concrete or glass, if used for the discussion). Your survey should cover an area of at least 60 square metres (e.g., 6x10 metres, or 4x15, or two storeys of 6x5 each). Be sure to take the analysis in Task 2.2 into account, by designing your survey to include walls, doors etc. it will be easier to write something interesting in Task 2.2.

For drawing the site maps, any drawing tool should work, for example LucidChart, or even presentation tools such as PowerPoint, Keynote or Google Slides. Modification of screen capture map (e.g., from Monash Digital Map) is acceptable provided that the appropriate references are provided or marks will be deducted. Use the APA 7th referencing style. Scans of hand-drawn maps are not acceptable.

An example map is given in the Appendix A. You may use any drawing tool to create a map (excluding heatmap generated by survey tools) or reuse existing floor plans with reference.

Conduct the survey

Your survey must include at least three WiFi access points. If you want, you can create an additional AP with your phone (using "Personal hotspot" or "Tethering" features).

For the survey, use a WLAN sniffing tool (see below) in at least eight different locations on your map. For each location, record the technical characteristics of all visible APs. Depending on the scanning tool you use, you record features such as the network name, MAC address, signal strength, 802.11 version(s) supported, band (2.4/5/6 GHz), channel(s) and security used.

Add the data into the map

Add the gathered data from the survey into the map of the covered area. On the map, indicate the location of the access points and the locations where you took measurements.

For the access points, use the actual location if you know it, or an approximation based on the observed signal strength (e.g. if you don't know exactly where it is).

For each measurement point, you either add the characteristics directly into the map using any annotation feature/tool, or create a separate table with the details. You can submit several maps if you choose to enter data directly into the maps, or a single map if you use additional tables. Create the map yourself, do not use the heat-map mapping features available in some commercial (i.e., paid) WiFi sniffing tools.

Task 2.2: Report
Write a report (word limit: no more than 1000 words) on your observations analysing the data collected in the previous step (Task 2.1). Your analysis must investigate the following aspects:

Channel allocation and overlap:
Are the access points using overlapping or adjacent channels?
Is there evidence of co-channel interference?
Suggest improvements to channel planning.

Signal attenuation and obstacles:
How do physical barriers such as walls, glass, or furniture affect the signal?
Compare at least two different material types in terms of attenuation.

Coverage and dead zones:
Identify areas with weak or no connectivity.
Recommend changes in AP placement, orientation, or transmit power to improve coverage.

Roaming and handoff potential:
Is there sufficient overlap between APs to allow seamless roaming?
How might roaming performance impact user experience (e.g., VoIP calls, video streaming)?

Network load and bandwidth usage:
Do multiple APs appear to be heavily utilised?
Suggest strategies to balance load or optimise performance.

Other analysis of your choice (1 or more):
For example:
Estimate AP locations from observed signal strength.
Test body attenuation.
Consider interference from non-WiFi devices (e.g., microwaves, Bluetooth).
Explain both your methodology and reasoning.

Report structure:
Task 2.2 requires you to write a structured report, not just a series of answers to the above questions. Ensure that your discussion flows logically, with each section connected and presented clearly (e.g., using sub-header to indicate the beginning of each section), rather than presenting unrelated short answers, or writing a single paragraph for the whole task and putting everything into it. Figures, tables, and references to your survey data may be included to support your analysis.

There are two sections for Part 3:

Section 1: The first section of the quiz requires you to download a PCAP file, open it in Wireshark and answer a few questions about the captured frames. The PCAP files are individualised, so make sure that you download the correct file while you are logged into Moodle.

Here are a few tips on how to approach these tasks.

Node Selection:
Please make sure you select the correct node (within your given scenario) for traffic analysis.

MAC addresses:
These are the addresses of individual devices at the Data Link Layer. Each frame contains a sender and receiver MAC address. For each frame, think about which device would be the sender and which the receiver.

IP addresses:
These are the Network Layer addresses. Remember that we use the DNS protocol to map a human-readable address (such as www.monash.edu) to an IP address (such as 202.9.95.188). So in order to find out the IP address for some of the devices, you may have to try to find DNS requests and responses in the PCAP file.

TCP connections:
Remember that each TCP connection starts with a three-way handshake. This was covered in the lectures, so you may have to go back to the videos if you're not sure what those frames look like.