COMP3331 Notices

COMP3331 Consult Update for tomorrow (Fri, 9th May)

Posted by Salil Kanhere 2 days ago.

I have to update the exam consultation time for tomorrow, 9th May, Friday, to 2 - 3 pm due to unforeseen clash. The updated schedule and web link are HERE .

COMP9331: Good luck for the final exam

Posted by Salil Kanhere 3 days ago.

Good luck, everyone. I don't mean to be Captain Obvious, but some advice:

• Make sure you know where to go. Check the exam timetable in myUNSW. The exam runs from 1:45 pm to 4:00 pm on Thursday, 8th May.
• Make sure to install the latest version of the Safe Exam Browser and test that it works by attempting the practice exam provided by the exams unit. You can check the UNSW information page about this here .
• Fully charge your laptop and bring your charger with you.
• Get a good night's sleep.
• Have some food before the start of the exam.
• Keep a water bottle handy.
• Don't panic if you cannot answer a question; move on and return to it later.
• Remember to answer all questions.
• Remember to breathe !!
• May the Force be with you all !!

COMP9331/COMP3331 – Lab and Assignment Marks Update

Posted by Isura Bamunusinghe Arachchige 3 days ago.

Finalized lab marks for all students and preliminary assignment marks for COMP9331 students have now been released. You can check your marks and feedback using the following commands:

3331 classrun -sturec

3331 classrun -collect Lab1 <-- Replace "Lab1" with the relevant lab or assignment name

You can also view the mark breakdown and your current overall mark here:

https://cgi.cse.unsw.edu.au/~give/code/login.php?app=/~give/Student/sturec.php

Finalized marks for all labs and assignments, including those for COMP3331 students, will be available by end of day, 13th May. If you have any concerns about your marks, please contact your tutor immediately and resolve them by end of day, 13th May .

Blank Paper in the Exam

Posted by Tim Arney 3 days ago.

Dear all,

During your exam you will be provided with an 8 page booklet to undertake any rough working out.

These will be collected at the end of the exam and destroyed at a later date.

Best of luck!

Urgent - SEB for Mac Version - correction to link

Posted by Tim Arney 5 days ago.

Dear Students,

A previous message from the university included an incorrect link for the Safe Exam Browser (SEB) for Mac.

The correct version for MAC is SEB 3.3.3 . Click here to download MAC 3.3.3 .

Please ensure this version is installed and verify that you can access the SEB Practice Test without issues.

You should be able to find the SEB Practice Test by:

• Logging into https://unsw.inspera.com/ and going to the "Demo tests" tab, or
• Following the link and instructions on https://www.student.unsw.edu.au/exams/inspera/on-campus

Kind regards,

Tim

Final Exam + myExperience

Posted by Salil Kanhere 14 days ago, last modified 14 days ago.

The assignment deadline has passed. I hope everyone has completed it and enjoyed the experience. However, you can submit it after the deadline, subject to the late penalty outlined in the specification.

Please complete the myExperience surveys . The response rate so far is low (only 26% ). I am sure we can do better. We would appreciate your feedback.

The final exam is scheduled as follows:

• COMP3331 - Thursday , 15th May, from 09:45 am to 12:00 noon.
• COMP9331 - Thursday, 8th May, from 1:45 pm to 4:00 pm.

The exam is in-person, invigilated and closed-book. You must bring your own laptop and install the Safe Exam Browser on it . Please check all the information for the exam here . There is a practice exam available that uses the safe exam browser. Make sure you try it out. Details are here .

I have created a final exam information page . Please read all the information provided here carefully, and be sure to check which content is examinable and which is excluded.

A practice final exam is available in Inspera. The Moodle link is posted on the Final Exam page. You can only sit this exam once, which will close in 2 hours + 15 minutes after you start the attempt. Please keep this in mind before attempting the exam. You should be able to view the correct answers in Inspera after you submit your attempt. I strongly encourage you to try the practice exam in Inspera to ensure that you are comfortable with the Inspera platform so that there are no surprises in the final exam.

I have also posted 2 PDF files of the exam (one with just questions, the other with questions and answers) on the Final Exam page.

Everyone is strongly encouraged to solve all the homework questions and engage in discussions on the forum.

I have arranged 5 exam consultation slots leading up to the exam dates. The schedule is here .

Have a good weekend, and good luck with your exam preparation.

Week 10: Final Week !!

Posted by Salil Kanhere 22 days ago.

Here are a few important announcements for next week, which will be the last teaching week of this term:

• In the lectures, we will wrap up the Wireless Network discussions we started last week and then move on to Network Security. The lecture slides are available.
• Lab 5 is due by 10 am on Tuesday, 22nd April . Next week, a tutorial will replace the lab (in your usual labs or online). This will serve as helpful practice for the final exam. Please look through the questions beforehand and try to solve them by yourself. All questions on the tutorial are from past exams, so effectively, it is a sample exam.
• We have two public holidays next week: Monday, 21st April (Easter Monday) and Friday, 25th April (ANZAC day). Alternate arrangements have been made for the Monday and Friday tutorials. Check the schedule here .
• Please complete the myExperience surveys . The response rate so far is very low (only about 10 % ). I am sure you all can do better. We would appreciate your feedback.
• Information about the final exam is now available on the Final Exam page. I will discuss the exam in the lecture on Wednesday. It is an invigilated on-campus exam and Inspera-based . You will need to bring your own device and install the Safe Exam Browser on it. Instructions are here .
• The assignment is due by noon on Thursday, 24 April . This is a hard deadline. Assignment consults are running, so seek help if you need it. Please test your code in VLAB before submitting it to avoid angst later. If your code does not run as expected in VLAB, then there isn't much we can do about it.

I know next week will be busy for everyone, but don't overwhelm yourself. Good luck with everything.

Reliability Testing for Assignment

Posted by Tim Arney 25 days ago.

We've made a proxy available on the CSE servers to simulate UDP packet loss.

Running the Proxy

To run the proxy, the basic usage is:

3331 lossy_proxy <request_port> <forward_port>

Here’s what those ports mean:

• <request_port> is the port that your clients should send their messages to, i.e. the "server_port" you give to your clients.
• <forward_port> is the port that your server should be listening on, i.e. the "server_port" you give to your server.

Important: These two ports must be different — the proxy needs to sit between the clients and the server so it can forward (or drop!) messages appropriately — and the proxy must be running on the same host as your server and clients.

Example

Say you run:

3331 lossy_proxy 49283 54923

That means:

• Clients should send messages to port 49283.
• The server should expect messages on port 54923.

Packet Loss

By default, the proxy simulates a 10% chance of dropping messages in both directions (client → server and server → client). You can change this using the `-f` (forward drop rate) and `-r` (reverse drop rate) flags:

3331 lossy_proxy 49283 54923 -f 0.0 -r 1.0

This configures the proxy to:

• Drop no packets from client to server (`-f 0.0`)
• Drop all packets from server to client (`-r 1.0`)

Don't worry too much — the marking won't aggressively test extreme loss scenarios. As long as your system can handle the occasional dropped packet (1–2 per interaction), you’ll be fine.

TCP Support

The proxy also tunnels TCP connections , so you can still use it to test commands like `UPD` and `DWN`. Note that TCP traffic is not made unreliable — the proxy passes it through without simulating loss.

Link Layer + Lab 5 + Assignment deadline approaching + Good Friday holiday

Posted by Salil Kanhere 29 days ago.

Several announcements for Week 9 (final two weeks !!):

• Next week's lectures will focus on the data link layer and wireless networks . Lecture slides are available. Several homework questions are posted. You are encouraged to work through them.
• Lab 4 is due by 10 a.m. on Tuesday, April 15th . Lab 5, held next week, is the last lab for the course. It will focus on TCP and Routing. For the exercises, you will use the NS-2 network simulator. The spec is available.
• Friday, 18th April, is a public holiday (Good Friday). All labs on Friday will be moved to other days as per the schedule HERE .
• The assignment deadline of noon on Thursday, 24 April, is approaching. This is a HARD deadline . Late submissions will be accepted but are subject to penalties as noted in the specification. Attend the assignment consultations if you need help. Details are HERE .
• IMPORTANT : We appreciate that many of you prefer to write code on your personal machine and in your preferred IDE (e.g. Eclipse). However, your assignment will be marked in the VLAB environment and executed through the command line. Thus, you must thoroughly test your code in VLAB before you submit it. If we cannot execute your code, we cannot award you any marks . Please pay attention to this point to avoid angst when marks are released.
• The final exam will be held on campus via Inspera (invigilated) as follows: COMP3331: 9:45 am to 12 noon on Thursday, 15th May, and COMP9331: 1:45 pm to 4:00 pm on Thursday, 8th May . Further information will be provided in Week 10. Mark that time in your calendar.
• Anonymous feedback about the course can be left here .

Have a good weekend, and see you in the lectures next week.

Ignore Moodle Percentage Mark for the midterm

Posted by Salil Kanhere about a month ago.

Moodle appear to be showing you an inaccurate percentage mark. Simply ignore it. Your mark in Inspera is the correct mark.

Mid-term Exam Marks Released

Posted by Salil Kanhere about a month ago.

The mid-term exam marks are now available. You can check your response and the correct answers to all questions in Inspera. Log into Moodle (or Inspera) and access the same mid-term exam link as before.

There is no pass or fail grade for the mid-term. It contributes to 20% of your final mark in the course. The final mark for the course will be computed as noted in the course outline.

Within Inspera, click "View Submission" on the main page to see the questions and your answers. The correct answers are visible at the bottom of each page under "Feedback". You can also navigate to the results page, which is after question 12 in the exam, to view a summary of your marks and the total mark.

On the main Inspera page, you will also see a candidate report ("View Report"). This includes answers to all questions as general feedback (same as in the above view) and specific feedback from your maker for the manually marked questions if marks were deducted.

Your total mark on the mid-term exam (out of 20) will also be available through WebCMS.

Questions 2 and 6 were manually marked. Where justified, partial marks were awarded. The rest of the questions were auto-marked. There are no partial marks for these questions.

Want to find out how you fared compared to other students? Check out the class statistics available here . I have included names of students who did very well. Congratulations.

Week 8: Network Data/Control Plane + Lab 4 + Assignment Consultations

Posted by Salil Kanhere about a month ago.

Here are a few announcements for next week:

• In the lectures, we will wrap up our discussion on the network data plane and move on to the control plane, where we will focus on routing algorithms. Slides are available.
• Several practice questions have been posted on the Homework Questions page. These cover TCP congestion control and the network data/control plane. Do make sure you work through them.
• In the lab (Lab 4), you will examine various aspects of TCP and become familiar with the ns-2 network simulator. Lab 4 is due by 10 am, Tuesday, 15 April.
• Midterm marks and class statistics will be available by early next week. Here is a poll about the exam.
• The assignment is due by noon on Thursday, April 24th. If you need help, you should attend the weekly assignment-specific consultations. The timetable is on the assignment page.
• Eligible students who wish to opt for the non-CSE version of the assignment MUST request approval ASAP by emailing cs3331@cse.unsw.edu.au . Otherwise, we will assume you are working on the regular version.
• Everyone will be busy for the remainder of this term. Please look after yourselves and your classmates. Do reach out to us if we can help in any way.
• Anonymous feedback can be left through the following link .
• Have a good weekend, and see you in the lectures next week.

Week 7: Midterm Exam + Programming Tutorial (during labs) + Assignment Consultations + Network Layer (Wed lecture)

Posted by Salil Kanhere about a month ago.

This is a reminder that the mid-term exam will be held on Tuesday, 1st April, from 14:15 to 15:30 . There is no lecture on Tuesday. The Inspera exam link is HERE (also accessible through the Moodle page for the course and the mid-term page). You can also access the exam via the Inspera page ( https://unsw.inspera.com/ ). The exam is open book/notes and remote. You are NOT required to use a safe exam browser for this exam.

If you wish to ask us questions, a Zoom meeting link is Meeting Room (Meeting ID: 88052588163, Password: 034482). You are not required to join the Zoom meeting, but if you do, you must mute yourself and ask questions in the chat.

You are strongly encouraged to download the latest version of the slides and any other content you expect to use during the exam to your local computer. The WebCMS server may be unable to handle the load if every enrolled student (around 1000) attempts to access the website simultaneously.

An exam consult will run on Monday, 31st March, from 4:30 pm to 5:30 pm in the Zoom Meeting Room (Meeting ID: 84966751062, Password: 047804). You will enter a waiting room. Please wait there, and I will let you in once I have answered the previous student's query.

The mid-term exam page has all relevant details about the exam. May the force be with you.

In the Wednesday lecture, we will get started with the Network Layer. Slides are available for review.

A programming tutorial will run during the labs in Week 7. There are distinct sessions for C, Java and Python. You can attend any session. A schedule is here .

Assignment consults will begin in Week 7 as per the schedule here . There are dedicated sessions for C, Java, and Python. You are encouraged to attend these sessions if you need help.

Programming Tutorial and Assignment Consultations

Posted by Salil Kanhere about a month ago.

We hope your preparations for the midterm exam are going well. Good luck!

We will begin offering you support for the programming assignment through a programming tutorial in Week 7 and consultation sessions from Weeks 7 to Week 10.

Programming Tutorial (Revised Timetable)

In Week 7, we will hold a programming tutorial instead of the usual lab session. The goal is to help you get started with the programming assignment. Please review the tutorial specifications in advance. We will get you to develop a simple chat application, which will have a direct carry-over to the assignment. The tutorial will have separate slots for Python, C, and Java, so attend the session based on your preferred language. Please check the revised timetable for week 7. Note that this tutorial is not graded or requires no code submission. Starter code is available for you to practice. Sample solutions will be made available by the end of week 7.

Assignment Consultations

Special assignment-specific consultations will be available weekly from Week 7 to Week 10 as per the schedule here . There are dedicated sessions for C, Java, and Python. You are encouraged to attend these sessions if you need help. The schedule may be updated occasionally, so please check it before attending (e.g. the location of the in-person session). Please note that the purpose of these sessions is to provide general assistance with programming, not for tutors to debug your code.

As the deadline approaches, we will aim to add more consultation slots based on demand, and any changes will be announced accordingly. However, we expect everyone to attend the programming tutorial in Week 7 to get a solid start on the assignment.

Information about Mid-term Exam + Flexibility Week (No lectures and labs next week)

Posted by Salil Kanhere 2 months ago.

The mid-term exam will be held during regular lecture hours (14:00 - 16:00) on Tuesday, 1st April (Week 7) . There will be no lecture on that day. The exam is remote and online .

Please review the information on the Mid-term Exam page (including terms and conditions, precise timing, content covered, exclusions, etc.). A short video (with slides) is also available.

The link for the exam will be circulated towards the end of next week and will also be available on the Mid-term page and the course Moodle page.

A practice exam is also available here: Moodle link . The exam uses the Inspera platform, which will be used for both exams in this course. You can only try the exam once , so please activate it ONLY when you are ready to take it. Answers are available as feedback in Inspera after completing the exam. The questions that require manual marking won't be marked. You'll be able to review the answers provided and compare them with yours. Everyone is strongly urged to attempt the exam. It will familiarise you with the Inspera assessment environment so there are no surprises on exam day. A PDF file with the exam questions and answers is posted on the mid-term exam page.

This is a reminder that there are no lectures or labs in Week 6 . You are all urged to use this week to prepare for the mid-term exam and start on the assignment.

You can provide anonymous feedback about the course here: Google Form .

Week 5: Exploring TCP and Congestion Control, Tutorial, Mid-term Exam coming up

Posted by Salil Kanhere 2 months ago.

Next week will be busy. Here is what's coming up:

• Lab 3 is due by 10 am Tuesday, 18th March.
• Next week, a tutorial will replace the lab (in your usual in-person or online room). It is not marked. It will serve as helpful practice for the mid-term exam. Please look through the questions beforehand and try to solve them by yourself. ALL questions are from past exams, so effectively, it is a sample exam paper. You can ask your tutor to prioritise questions that you find difficult. The question set is released.
• In the lectures, we will explore TCP in detail, followed by a discussion on congestion control. Slides are available. I am overseas for a conference next week. Isura, our course admin, will deliver the lectures. Please be nice to him.
• The mid-term exam will be held during regular lecture hours ( 14 :00 - 16:00 ) on Tuesday, 1st April (Week 7) . Towards the end of next week, further information about the format and a sample exam will be available. The exam makes up 20% of your final mark.
• Lab 2 marks and solutions will be available by mid-next week. If you have questions about your marks, please get in touch with your tutor.
• The programming assignment specification was released last week. Please read it carefully. I have recorded a video providing an overview and some general tips. It is linked to the assignment page.
• Everyone is encouraged to discuss the homework questions on the Ed discussion forum. All of these questions are from past exams. We will be happy to add comments to your answers.
• Please complete this poll and let us know which programming language you plan to use for the assignment. This will help us schedule help sessions from Week 7.
• You can provide anonymous feedback about the course through the following link.
• Flexibility Week ( Week 6, 24-28 March ) is nearing. There will be no lectures or labs that week, allowing you to catch up, prepare for the mid-term exam, and get going with the assignment.

Have a good weekend and a great week ahead. Over and out.

Week 4: Getting Busy (Transport Layer, Lab on DNS + TCP Socket Programming, Assignment Released)

Posted by Salil Kanhere 2 months ago.

Several announcements for Week 4. Read carefully:

• The lab 2 deadline is 10 am on Tuesday, 11th March .
• Lab 3 has been released. It will require you to learn the nitty-gritty of DNS and gain experience with TCP socket programming.
• In the lectures, we will begin our journey into the Transport Layer . Slides are available for review.
• Here is a poll on the pace of the lectures . Let me know your thoughts so I can make adjustments as necessary.
• The assignment specification is available. It is long but for a reason. Read it carefully, and then reread it (and again). The deadline is noon, Thursday, 23 April (Week 10). Assignment-specific consultations will be arranged in Weeks 7-10. A programming tutorial is scheduled during lab hours in Week 7 . Details will follow for both. In the meantime, post questions to the Ed forum.
• The mid-term exam, worth 20% of the course mark , will be held on Tuesday, 1st April (Week 7) , during regular lecture hours (14:00 - 16:00). It will be held online (remote) on the Inspera assessment platform. Further information and an online sample exam will be available in Week 5.
• The solutions to Lab 1 and your marks will be released by the middle of next week. Please cross-check the solutions to determine why marks were deducted (if any). If you have questions about marking, ask your tutor. The easiest way to access your marks is through the WebCMS interface. Click on the Grades icon beside your name at the bottom of the left frame.
• Everybody is strongly encouraged to discuss solutions to all homework problems on the course forum. Several questions are from past exams and will prepare you for the mid-term and final exams.
• If you haven't joined the Ed discussion forum, here is the link - https://edstem.org/au/join/dS38xh .
• An anonymous feedback form is available here if you have comments for us.

Have a great weekend, and see you at the lectures next week.

Week 3: Continuing our explorations of the Application Layer + Lab 2 (HTTP)

Posted by Salil Kanhere 2 months ago.

The Lab 1 report is due by 10 a.m. on Tuesday, March 4th . Submission instructions are in the lab spec. Submissions received via email will NOT be entertained.

We will wrap up last week's leftover content in the lectures and study DNS, Peer-to-peer applications, and socket programming. The slides are available for review.

In Lab 2, we will explore HTTP and learn to use a new tool called Wireshark, a protocol analyzer. Wireshark is installed on all lab computers and in VLAB. You can also install Wireshark on your machine. It is free and works on all operating systems. Download it here . You will also get your first exposure to socket programming. Sample working client/server programs in C/Java/Python are available here .

The assignment specification will be released next week.

Very few students appear to be attempting the homework questions. We strongly encourage everyone to work through these questions on their own. We will post answers to the collated questions (e.g., Introduction Questions). However, the questions marked with " Students to Discuss Solutions " are exclusively left for you to work on. Please post your solutions on the Ed forum. We are happy to provide feedback on your attempts. This should serve as excellent practice for the exams.

You can join the Ed Discussion forum via the following link - https://edstem.org/au/join/dS38xh .

An anonymous feedback form is available here if you wish to leave us some comments. We will try our best to respond to your input.

The mid-term exam will be held on Tuesday, 1st April (Week 7), during regular class hours (14:00 - 16:00) . Mark this time in your calendar. It will be held online (remote) using the Inspera platform. A sample exam will be available for you to try, and details will follow.

Have a good weekend, and see you in the lectures next week.

Week 2: Labs Commencing, Wrapping up the Introductory Content and Diving into Applications

Posted by Salil Kanhere 3 months ago.

In the Week 2 lectures, we will complete our introduction to computer networks (protocol layering) and dive into networked applications (principles, Web/HTTP, Email). Slides are available for review.

Labs will commence in Week 2. Please attend the lab class you have enrolled in, as many classes are at full capacity . Note that we have a mix of in-person and online labs. Recordings will be available for online labs and accessible through the Labs page. You will notice a few parallel lab classes, e.g., M12A and M12B. Make sure you attend the correct class as per your UNSW timetable. If attending an online lab, you are strongly urged to set up access to the VLAB environment before the lab . It is not an efficient use of your tutor's time if they have to explain this process to you during the lab. We encourage the use of TigerVNC. Check the instructions here . The first lab exercise is now available. You are strongly urged to read the Tools of the Trade introductory lab before attempting the first exercise. The first lab report is due by 10 am Tuesday, 4th March (Week 3) . Submission instructions are in the lab specification.

Several problem-solving questions are accessible on the Homework Questions page. You are strongly encouraged to work through these questions on your own. These are not assessed. We will post answers to the collated questions (e.g., Introduction Questions). However, the questions marked " Students to Discuss Solutions " are exclusively left for you to work on. We are happy to provide feedback on your attempts but will not provide ready solutions. Working through these questions will provide good practice for the exams. Please discuss them on the Ed forum. You can join the forum via the following link: https://edstem.org/au/join/dS38xh .

My consultations are scheduled for Tuesday from 4:30 to 5:30 p.m. The course outline page has a link to the Zoom meeting. Alternatelty, you can stop by my office.

This is an early heads-up that the mid-term exam will be held on Tuesday, 1st April (Week 7) , during regular lecture hours (14:00 - 16:00) . Mark this time in your calendar. The exam will be held online using the Inspera platform; details will follow.

Have a great weekend, and I look forward to seeing you during the lectures on Tuesday & Wednesday and online on the forum!

Week 1: Ready, Set, Go.

Posted by Salil Kanhere 3 months ago.

Our first lecture will be held on Tuesday, 18th February, from 14:00 - 16:00 in Physics Theatre.

All content for Week 1 is now available on the Lectures page.

I am told live streaming is enabled (to be tested tomorrow). However, I won't be able to answer any questions posted to the stream chat. Lecture recordings will be available on Echo360.

Make sure to read through the course outline before the lecture.

There are NO labs in Week 1, even if your calendar in myUNSW may say so. Labs will commence in Week 2. A self-study lab that introduces you to the various networking tools used in the course is available. Please make sure you go through it this week.

We will use Ed Discussions for the course forum. The default WebCMS forum has been disabled. Please join the forum by clicking on this link: https://edstem.org/au/join/dS38xh .

Please post any course-related questions on the Ed forum. If you must email us, use cs3331@cse.unsw.edu.au instead of our personal emails.

For enrollment issues, contact the Student Nucleus Hub . Course staff do not have access to the enrollment system.

We would appreciate it if you could complete the following poll: Your Internet speed .

See you in the lecture tomorrow !!

Welcome Padawans to COMP3331/9331, Term 1, 2025

Posted by Salil Kanhere 3 months ago, last modified 3 months ago.

Welcome to COMP3331/9331, Term 1, 2025 . The course webpage is at www.cse.unsw.edu.au/~cs3331

The course is being offered in a hybrid mode. All lectures will be in person but recorded and made available via the Echo360 platform in Moodle . We have a mix of in-person (most) and online (few) labs, and consultations will be hybrid. The exams, both the midterm and final, will use the Inspera exam platform. However, the midterm exam is non-invigilated (take home), with open books and notes, while the final exam is invigilated (on campus) and closed-book.

Please check your enrolment and attend the appropriate lab class. If you have enrollment issues, please contact the Nucleus Student Hub. The course staff do not have access to the enrollment system.

Please read the course outline carefully.

Our first lecture will be on Tuesday, 18th February, from 014:00 - 16:00 in Physics Theatre.

All content for Week 1 is now available on the Lectures page.

Labs will commence in Week 2 , even if your timetable indicates they start in Week 1. Details are on the Labs page.

We will be using Ed Discussions for the course forum. Please join via this link. The forum on WebCMS is disabled. Please post any course-related questions on the Ed forum. If you must email us, use cs3331@cse.unsw.edu.au instead of personal emails.

We would appreciate it if you could complete the following poll: Your Internet Speed .

See you on Tuesday !!