COMP3331 Notices

Final Exam Sample Solution is available

Posted by Wen Hu Friday 28 May 2021, 04:16:13 PM.

in Final Exam .

I wish you all enjoyed the (short) break and best wishes for the future. Do stop by and say hello in person if you are on campus in T2. Stay safe!

Supplementary Exam and Final Exam feedback

Posted by Wen Hu Thursday 20 May 2021, 10:32:27 AM, last modified Thursday 20 May 2021, 10:32:42 AM.

1. The Supplementary exam will be held on Wednesday 26/05 from 2pm. Students approved to sit the exam have been emailed specific details. Further information is available in the following link Final Exam (under Section Supplementary Exam).
2. The results of this course are available in myunsw. I have arranged a session for the students that are looking for final exam feedback at 2pm to 4pm 24/05 Monday. Please see the following link for the details: https://webcms3.cse.unsw.edu.au/COMP3331/21T1/reso...

Final Exam and Final Marks are released

Posted by Ayda Valinezhad Orang Saturday 15 May 2021, 12:12:29 PM, last modified Saturday 15 May 2021, 12:14:45 PM.

Dear All,

Your final exam marks and total marks are available.

401 students attempted the exam. Some statistics: Max mark possible: 40 , Max mark achieved: 39.5 , Min mark achieved: 3 , Average: 27.98, Standard Deviation: 5.36 .

Regards,

Ayda

Final exam will start in 15 minutes

Posted by Wen Hu Friday 07 May 2021, 01:46:35 PM.

I have made the links visible in Final Exam and Moodle, but you won't be able to attempt it till 2pm.

Good luck!

Good luck for the final exam

Posted by Wen Hu Thursday 06 May 2021, 02:41:23 PM.

• The consultation ended at 12:30, and if you have any last minute questions, please post them in the webcms. The consultation was overtime and full, and I appreciated that you helped each other in the breakout room when I talked to the other students.
• Good luck everyone in tomorrow's final exam, and I copy some information below.
  • Final exam details .
  • Get a good night's sleep
  • Have some food prior to the start of the exam
  • Keep a water bottle handy
  • Find a quiet and comfortable room where you are unlikely to be interrupted for the duration of the exam
  • Make sure your computer is charged and connect it to a power outlet
  • If you are on a shared network then make sure others using the network will not engage in heavy usage
  • Download all lecture notes and homework questions to your computer to avoid potential bottlenecks with the WebCMS server
  • Don't panic if a question stumps you, move on and come back to it later
  • Remember to answer all questions in both parts (the # of questions in each part are stated on the front page).

Assignment Marks

Posted by Ayda Valinezhad Orang Wednesday 05 May 2021, 10:47:02 AM.

Dear All,

I hope everything is going well for you.

I want to let you know that assignment marks are available. However, a very small number of submissions encountered problems in testing/marking, so please check your marks and if there are any issues with your marks contact us ( cs3331@cse.unsw.edu.au ) by the 13th of May, considering that any request regarding any issues with the assignment marks after this deadline would be declined .

Good luck with your final exam!

Regards,
Ayda

Week 12: Final exam reminder + consultation

Posted by Wen Hu Monday 03 May 2021, 09:45:36 AM.

A few announcements:

• It is Week 12, and there will be no new lecture for the course.
• Last week's consultation was pretty full (I appreciate your patience), and I have arranged one more consultation between 10am - 12pm, 06/05 Thursday. Please see this link for the Zoom details.
• A final reminder that the final exam will be held between 2:00 pm - 4:05pm, 07/05/2021, Friday, Sydney time . There is extensive information about the final exam on the specific final exam page . A practice exam is available in Moodle and linked from the exam page. Everyone is STRONGLY encouraged to attempt under exam-like conditions. ELS students have been emailed about their specific arrangements.
• Lab marks and feedback (if marks are deducted) for all labs are now available. Assignment marking is under way and we hope to release the marks later this week.
• We thank you for your (myExperience and Google form) feedback and all the best for your final exam.

Extra final exam consultation

Posted by Wen Hu Thursday 29 April 2021, 01:19:31 PM.

• Due to popular demand, I have arranged one more consultation between 10am - 12pm, 06/05 Thursday. Please see this link for the Zoom details.
• A final reminder that myExperience surveys will close tonight (mid-night). Thanks to everyone who did their bit, and we have reached a 37% response rate. If you haven't done so, we will appreciate it very much that you can complete it before the deadline.

Week 11: No lectures + Consultation + myExperience Feedback + Final Exam Reminder

Posted by Wen Hu Monday 26 April 2021, 09:46:00 AM.

A few announcements:

• It is Week 11, there will be no new lecture for the course.
• I have arranged a final exam consultation on Thursday, 29 April . Please drop by if you have any questions.
• I understand that you are all busy with exam preparations. However, we would very much appreciate if you could complete the myExperience surveys for this course. We have reached a 22% response rate. Thanks to everyone who did their bit. However, I am sure we can do better. The survey closes on Thursday, 29 April , so please complete it as soon as possible.
• A reminder that the final exam will be held between 2:00 pm - 4:05pm, 07/05/2021, Friday, Sydney time . Details are on the final exam page . A practice exam is available in Moodle and linked from the exam page. Answers to all homework questions are available to help you prepare for the exam. If you have any questions, please post them in webcms or come to my consultation discussed above.
• Assignment marking has started. We hope to have marks ready next week.

Final Lecture + Final Exam Detail

Posted by Wen Hu Wednesday 21 April 2021, 10:54:08 AM.

• Tomorrow is our final lecture . I will wrap up the remainder of the content on link, recap what we have learnt in the course and discuss about the final exam (content coverage, logistics, type of questions, how to prepare, etc.). Come and say good bye.
• The final exam will be held on 2:00 pm - 4:05pm, 07/05/2021, Friday Sydney time . It will be an online Moodle quiz in two parts. Part 1 will run from 2pm to 3:05pm. There will be a 5 minute break. Part 2 will run from 3:05pm to 4:05pm . Further details about the final exam including a link to a practice exam (in two parts) are available on the final exam page . Please make sure that you read all information on the page carefully.
• There is a masterclass on the InterPlanetary File System (a protocol of peer-to-peer network for storing and sharing data in a distributed file system, e.g., blockchain), which may be of interest to some of you. Registration is free and a Certificate of Completion is available upon completion of the course.

Week 10: Final Week of Lectures, Lab 6 and Assignment deadlines, Extra Assignment Consultations, Tutorials replace Labs

Posted by Wen Hu Monday 19 April 2021, 09:38:17 AM.

A few important announcements for this week:

• This is our final week of lectures . We will wrap up Link Layer (and the course) this week, and will discuss about the final exam on Thursday. Come and say good bye !!
• Due to the CSE server outage last week, the deadlines for Lab 6 and Assignment have been extended for 2 days respectively. Lab 6 is due by 11:00 am Thu 22 April 2021, and the assignment is due by 11:59am Sun 25 April 202 1 . Upon many requests, we also arranged extra assignment consultations this week. Please attend them if you need help. If you have created additional files (beyond the base server.* and client.*), please feel free to group them under two sub-directories ( server and client ) in your archive. This will be helpful for us while marking.
• There will be a tutorial replacing the lab (in your usual Zoom/Teams meeting) this week. This will serve as useful 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.
• Please complete the myExperience surveys . The response rate so far is rather poor (less than Faculty and School averages). We would appreciate your feedback.
• The final exam will be held on 2:00 pm - 4:05pm, 07/05/2021, Friday Sydney time online (Moodle) . Later this week I will make available several resources for the final exam including a practice exam. Stay tuned for further details.
• I know this is a busy week for everyone but make sure to not overwhelm yourself. Good luck with everything.

Extra Assignment Consultation in Week 10.

Posted by Wen Hu Sunday 18 April 2021, 09:51:58 PM.

Upon many requests, we have arranged new assignment consultations in Week 10. The schedule is available here https://webcms3.cse.unsw.edu.au/COMP3331/21T1/reso...

CSE servers encountered some issues for the past day or so

Posted by Wen Hu Friday 16 April 2021, 06:10:48 PM.

Hi all,

We understand that the CSE servers encountered some issues, which have been fixed. It is unfortunately possible that some students have lost all their files in their home directories and will only discover this when they next log in.

If you have lost all your files, you can try restoring them following these instructions. If this doesn't work, or you need help, please email helpdesk@cse.unsw.edu.au . Please be patient, it may be well into Monday before System Support can help everyone.

As such, the deadlines of Lab 6 and Assignment will be extended for two days.

myExperience feedback and extra information on midterm exam solutions

Posted by Wen Hu Wednesday 14 April 2021, 10:06:16 AM.

1. The myExperience surveys are open. Please provide feedback so that we can improve the course for future offerings. You may also use the direct link in Moodle to access the course survey.
2. We have produced extra (step-by-step) information for the solutions of midterm exam here . Please post the questions in the webcms page or come to my consultations if you still confused about the solutions.

Week 9: Wrap-up Network layer + Link Layer + Lab 6 + Assignment deadline approaching + myExperience feedback

Posted by Wen Hu Monday 12 April 2021, 10:58:19 AM.

A number of announcements:

• In the lectures this week, we will wrap-up network layer and start data link layer . A number of homework questions are available. You are encouraged to work through them.
• Lab 5 is due by 11:00am Tue 13 April 2021 . Lab 6 held this week is the last lab for the term. A reminder that we will pick your 5 best lab scores (out of 6). Lab 4 marks should be available in the next couple of days (are available for most already).
• The assignment deadline ( 11:59am Friday, 23 April 2021 ) is approaching soon. Attend the assignment consultations if you need help.
• 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 through command line execution. It is thus imperative that you thoroughly test your code in VLAB before you submit. If we cannot execute your code then we cannot award you any marks . Please pay attention to this point to avoid any angst when marks are released.

(Updated) Week 8: Final Exam timetable + Network Data/Control Plane + Midterm result + Lab 5 + Assignment Consultations

Posted by Wen Hu Tuesday 06 April 2021, 09:54:40 AM, last modified Tuesday 06 April 2021, 04:50:18 PM.

I hope that you had a great long weekend. Here are a few announcements this week:

• 21T1 final Exam timetable has been released. COMP3331/9331: Afternoon (1pm - 5pm), 07/05, Friday . Please mark your calendar.
• Mid-term Exam marking is available. We have released marks (SMS and webCMS) and solutions (via Moodle ). We have been as generous as we can in rounding up the marks.
  • Statistics: Mean: 12.07; Median: 12; Max: 20; Min: 3; STD: 3.
• In the lecture this week we will wrap up our discussion on the network data plane; and hopefully move on to the control plane where we will focus on routing algorithms.
• A number of practice questions have been posted under the Homework Questions page. These cover TCP congestion control and the network data plane. Do make sure you work through them.
• Lab 4 is due in ~one hour.
• Lab 5 is out and will include exercises that use the ns-2 simulator where you will investigate TCP congestion control.
• The assignment is due at 12:00, 23/04/2021 . If you need help, then you should attend the assignment specific consults. The timetable is on the assignment page.
• I know the next few weeks till the end of the term are going to be busy for everyone. Do make sure that you take care of yourself. Do reach out to us if we can help in any way. There is counselling support offered by the university if you require it. For special considerations, please follow the instructions on this page .
• You are welcome to provide anonymous feedback about the course through the following link .

Easter Monday and daylight savings time

Posted by Wen Hu Sunday 04 April 2021, 08:30:38 PM.

1. For the students located remotely, please note that Daylight Savings Time ended this morning in NSW. Please adjust your lecture, lab and assignment consultation timetables accordingly.
2. It is a public holiday tomorrow; hence, there is no lecture. Enjoy your long weekend!

Week 7: Mid-Term Exam (Today) + Lab 4 + Assignment Consults + Getting Started with the Network Layer

Posted by Wen Hu Monday 29 March 2021, 09:25:09 AM, last modified Monday 29 March 2021, 05:31:17 PM.

I hope all of you enjoyed your mid-session break and have used it well to prepare for the exam and get started with the assignment. Here are the key announcements for this week:

1) The Mid-term Exam will be held at 2:10pm today. The exam will be held online in Moodle and is made up of two parts: Part 1 (14:10 -- 14:40, Sydney time) and Part 2 (14:45 -- 15:15, Sydney time). The links to the two parts will be available in WebCMS mid-term exam page at 14:00. You cannot start the second part of the exam before the noted time. You will not be able to return to the first part once you move to the second part. All unsaved attempts will be automatically saved when the time expires. If you have questions or technical issues, you can join Monday's lecture Zoom session . Although there is NO requirement to join the Zoom session, you are encourage to join (e.g., to avoid panic when you do have a question or encounter technical issues with Moodle). You will be allocated to a breakout room supervised by a tutor during the exam and please raise your questions to the tutor (we will have a back channel for the communication among ourselves). There is extensive information about the mid-term exam on the specific exam page . A practice exam is also available, and I can see there are 586 attempts currently. If you haven't done so, you are STRONGLY encouraged to attempt under exam-like conditions. There was a typo in the answer for the RTT estimation question in the Mock exam , which I fixed on last Thursday. If you did the Mock exam before Thursday, I suggest you to check it out . Our apologies for the inconvenience. Finally, I wish you good luck !!

2) In the lab this week (Lab 4), you will work through a couple of exercises on TCP. You will also familarise yourself with a network simulator called ns2, which will be used in subsequent labs. Lab 4 reports are due by 11:00 am Tue 06 April 2021 .

3) Special assignment specific consultations will run every week from Week 7 to Week 10. There are dedicated sessions for C, Java and Python. You are encouraged to avail of these sessions if you need help. Note that, the purpose of this session is to provide general help and NOT for tutors to debug your code. The schedule is on the assignment page.

4) There will be no lecture today We will commence our journey into the network layer on Thursday. Lecture slides will be available later today.

CSE servers (including the one hosting WebCMS)

Posted by Wen Hu Monday 22 March 2021, 11:25:26 PM.

will be offline between 7pm Fri 26 March and 8pm Sat 27 March.

Week 6: No Labs and Lectures and further details about the Mid-term Exam

Posted by Wen Hu Monday 22 March 2021, 09:40:17 AM.

For the students in NSW (esp. those in Western Sydney and northern NSW), I hope that you and your family are safe and dry during this once per decades flooding event.

• A reminder that there are no labs or lectures this week . Students are encouraged to use this week to prepare for the mid-term exam and work on the assignment.
• At the end of last Thursday's lecture, I briefly went over the content included on the exam, exclusions, type of questions, preparation advice, etc. You can check it out on Echo 360 and the slides are available on the Mid-term Exam page. Please post your questions in the webcms if you have any.
• A reminder that the mid-term exam will be held during regular lecture hours (14:00 - 16:00) on Monday, 29 March (Week 7) . Further information is available here . The exam makes up 20% of your final mark. I will be available for a pre-exam consultation session in the regular consultation time (Thursday 11:00 - 12:00) . Meeting link is available on the Lectures page .
• Solutions for all homework questions are now available. If you haven't done so, we suggest you to go through the questions yourself before looking at the provided example solutions. This will help you to prepare for the mid-term exam a lot.
• Thanks for your input on the poll of programming language choice for the assignment. We have arranged the consultation schedule accordingly. Note that the consultation starts from Week 7.
• Marks for lab 3 will be released in the next couple of days.

Week 5: Exploring TCP and Congestion Control, Tutorial, Mid-semester Exam Preparations

Posted by Wen Hu Monday 15 March 2021, 10:53:27 AM.

Announcements for Week 5:

• Lab 3 is due by 11:00 am, Tue 16 March 2021
• There will be a tutorial replacing the lab (in your usual Zoom/Teams meeting) this week. It is not marked. This will serve as useful practice for the upcoming exam. Please look through the questions beforehand and try to solve them by yourself. You can ask your tutor to prioritise questions which were particularly difficult for you.
• In the lectures we will explore TCP in detail and and go over the principles of congestion control. Slides are available.
• There will be no lectures or labs in Week 6.
• The mid-term exam will be held during regular lecture hours (14:00 - 16:00) on Monday, 29 March (Week 7) . Further information is available here . The exam makes up 20% of your final mark.
• We will aim to release Lab 2 marks and solutions in the next couple of days.
• The deadline for choosing the non-CSE option for the assignment is 5pm, 18 March (Friday, Week 5) . Only students w ho are not enrolled in a CSE program are eligible. Further details are in the spec. Requests after the deadline will not be entertained.

Have a productive week and see you all in the lectures.

POLL on Pace of Lectures

Posted by Wen Hu Tuesday 09 March 2021, 03:47:19 PM.

We are in Week 4, please let us know your view on the pace of course lecture delivery pace so far here: https://webcms3.cse.unsw.edu.au/COMP3331/21T1/acti...

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

Posted by Wen Hu Monday 08 March 2021, 09:49:04 AM.

A number of announcements this week. Read carefully:

• Lab 2 deadline is 11:00 am, Tue 09 March 2020.
• Lab 3 is released and will require you to get into the nitty-gritty of DNS and TCP socket programming.
• In the lectures this week we will first wrap up some of the left over content on the Application Layer and begin our journey into the Transport Layer.
• The mid-term exam which is worth 20% of the course mark, will be held on Mon 29 March (Week 7) during regular lecture hours. The exam will be held online through Moodle. Further information and a sample online exam will be available before the end of next week.
• The solutions to Lab 1 and your marks for the same will be released in the next day or two . Please cross-check the solutions to find out 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 marks icon located besides your name at the bottom of the left frame.

Have a great week and see you in lectures.

Assignment is released

Posted by Wen Hu Wednesday 03 March 2021, 09:09:12 AM.

The assignment specification is available. It is long but for a reason and worths 20% of the course mark. Read it carefully. Read it again (and again). The deadline is noon, Friday, 23 April 2021 (Week 10). Assignment specific consultations will be arranged in Weeks 7-10. Details will follow. In the meantime, any questions should be posted as comments on the specifications page on WebCMS.

Week 3, Wrapping up Application layer and Lab 2

Posted by Wen Hu Monday 01 March 2021, 11:02:44 AM.

The first lab report is due by: 11:00 am, Tue 02 March 2021 . Submission instructions are in the lab spec. Submissions received via email will not be entertained.

In the lectures, we will wrap up our coverage of the application layer, which includes e-mail, DNS, P2P and CDN.

In Lab 2 , we will explore HTTP and learn to use a new tool called Wireshark, a protocol analyzer. We strongly encourage you to install Wireshark on your machine (instead of running it through VLAB). It is free and works on all operating systems. Download it here .

Homework questions

Posted by Wen Hu Thursday 25 February 2021, 09:21:32 PM, last modified Thursday 25 February 2021, 09:21:54 PM.

As discussed in today's lecture, a number of problem solving questions are accessible on the Homework Questions page. You are strongly encouraged to work through these questions on your own. We will post answers for the collated questions (e.g. Introduction Questions). However, the questions marked with " 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.

Labs and VLAB

Posted by Wen Hu Wednesday 24 February 2021, 02:24:32 PM, last modified Wednesday 24 February 2021, 08:45:51 PM.

Hi all,

Labs started this week and I hope that it goes well for you. If you encounter any problems, please let us know via WebCMS forum (preferred) or the other channels (e.g., email to class account, cs3331@cse.unsw.edu.au).

If you can't come to campus (e.g., CSE labs), VLAB has the same set up as the computers in the labs, whose software and OS environments that we are mostly familiar with (e.g., the assignment submission will be required to be compilable in the CSE servers so that we can compile and test it.). Therefore, we suggest you to use Vlab whenever possible. Note that Vlab has been used in this course for three terms in 2020, and we are confident that it will meet the requirements of most (if not all) of you.

For the students that are based overseas, there will be latency/delay and throughput issues (as we learnt in the lectures this week). Here are some hints to speed it up.

1. For the students in China , you may want to try Chinese Student Access Network (CSAN), which provides high speed links between UNSW and China https://www.myit.unsw.edu.au/services/students/chi...
2. You don't need VPN to access VLAB, it actually will slow you down. There is also a web interface available ( https://vlabgateway.cse.unsw.edu.au ) available (you may choose a lower screen resolution to improve response time).
3. You may use SSH log into CSE servers instead of VLab and run the commands (e.g., traceroute) from there. On your terminal %ssh z1234567@login.cse.unsw.edu.au (replace z1234567 with your zid). Y option will enable GUI over SSH, e.g., %ssh -Y z1234567@login.cse.unsw.edu.au. More details available here https://taggi.cse.unsw.edu.au/FAQ/Logging_In_With_SSH/ . Note that the environment set up in CSE servers may be different to VLab. For example, %ifconfig is replaced with %ip address in CSE servers. Therefore, we recommend VLab instead of SSH.
4. You install the necessary software in you own machine and use UNSW VPN server (choose library resource access instead of the default setting, i.e., vpn.unsw.edu.au/library ) as if you were physically located on campus. However, in such way, it will be difficult for us to support you since we may not familiar with your OS and software versions.

Labs start this week. Week 2 lecture slides are posted

Posted by Wen Hu Monday 22 February 2021, 11:08:20 AM.

Please attend the labs that you are allocated to.

echo360, polls, Moodle and WebCMS access

Posted by Wen Hu Wednesday 17 February 2021, 08:35:44 AM.

Hi all,

• The recording of Week 1's lecture is available in echo360 .
• Please participant in the polls if you haven't done so. We have about 30% return rates currently and they will be closed tonight.
• For the students enrolled to the course recently, it will take up to 48 hours for the systems (enrolments, Moodle, and Webcms) to synchronise. Please contact us if you can't access the systems after 48 hours of your enrolments.

Homework/Quiz questions

Posted by Ayda Valinezhad Orang Tuesday 16 February 2021, 10:42:24 AM.

Dear All,

Welcome to COMP3331/9331. Hope you have a very successful term.

Homework questions will be released each week, so, you have time to discuss questions. Then, we will release answers next week.

Just letting you know that week1 Homework questions was released.

Regards,

Ayda

Week 1 lecture slides are posted

Posted by Wen Hu Monday 15 February 2021, 10:54:32 AM.

I look forward to meeting you this afternoon.

Welcome to COMP3331/9331 21T1.

Posted by Wen Hu Sunday 07 February 2021, 09:36:23 PM.

The lectures will be delivered online via Zoom. Please see here for the details. I am looking forward to meeting you all on Monday, 15/02/2021.