Data Networks

Dear Students,

Below you will find some important details regarding your Data Networks exam:

Exam Date: 
  - August 2nd at 9:15 am (You can enter the exam room at 9:00 am) 

Exam Venue: 
   We will be using three different rooms. You are assigned to one of the rooms based on your matriculation number: 

    * Günter-Hotz Lecture Hall Building (E2.2): Numbers: 2539352 to 7038737 (inclusive) 
    * Lecture Hall 02 Building E1 3:                   Numbers: 7038817 to 7043840 (inclusive) 
    * Lecture Hall 01 Building E1 3:                   Numbers: 7046255 to 7048036 (inclusive)

Seat assignments:
  You will find your assigned seat according to the list posted on the doors of the lecture rooms. 
  On your seat you will find your personalized assignment. Therefore, do not use any other seat. If you are unsure, please contact a tutor outside the hall before you enter the hall or in the hall afterwards. 

Important Reminders:
* Be punctual and arrive at the exam venue well ahead of time to avoid any last-minute rush.
* Remember to bring all necessary examination materials, such as your student ID and pen(s) required for your exam.
* Adhere strictly to the examination rules and regulations put forth by the university.
* Maintain an atmosphere of quiet and respect for fellow students during the exam.
* During the first 60 minutes of the exam you will only be allowed to leave the exam hall in cases of emergencies. (Please use the restrooms before entering the exam hall.)
* During the last 15 minutes of the exam you will again only be allowed to leave the exam hall in cases of emergencies.
* During the remaining time it is OK to 
    * hand in your exam an leave the room
    * for 1 person at a time to leave the room to use the restroom

We wish you all the best for your exams! 

Best regards,
You DN Team

The purpose of this announcement is to help you prepare for the Data Networks
exam.  In principle, the exam covers all content discussed in the lectures and
the tutorials.  However, the focus will lie on tasks asking you to APPLY your
knowledge, i.e., there will be very few questions expecting free-text,
essay-like answers.  Be prepared to solve tasks by applying your knowledge to 
various scenarios, covering all network layers and their interactions.

Please adhere to the following rules:
- Do not write before the start of the exam and after the end of the exam 
- Do not use phones/calculators or other electronic devices such as watches with online capabilities
- Use black or blue pens only  
- Do not talk with others
- Do not exchange notes with others
- For the exam, one A4-sized sheet of notes is allowed, only yours to use. Write your first name, last name, matriculation number, and add your signature on BOTH sides of the A4 paper. 

For your information, you find the meta content of the exam below:

Good luck!

==========================================================================================
Texts to Read Carefully: Cover Sheet
==========================================================================================

- Check your personal data, write the date and place, and sign on the cover sheet.

Text Below the table and the Signature Field on the Cover Sheet

• Only one A4-sized sheet of notes is allowed as auxiliary material.
   Please put your name, your Matrikelnumber, on both sides and sign next to it.
• Do not write in red or green and do not use pencils.
• You have 150 minutes to complete the exam.
• If required, you can request additional paper in case the last empty page is not sufficient.
• Your exam will be graded anonymously. Thus, please provide the above given exam ID (XXX) on every additional piece of paper.
• Overall, you can achieve 100 points. 50 points are sufficient to pass the exam (grade: 4.0).
• Place your identification card and student ID card next to you on your table.
• This exam consists of (17) A4 pages, including the cover sheet.
==========================================================================================

Multiple Choice Introduction Text

The following questions are multiple choice questions. For each question: 
    • At least one option is True
    • At least one option is False
Mark all the true choices with a cross in the circle to the right. 
Correct a misplaced cross, by drawing a new circle to the right of the line. 
You can correct multiple times by repeating this process. We will only count the right-most circle.

To get points for a question, all options have to be correctly marked, and at least one option has to be marked as ’correct’.
==========================================================================================
 

Dear Students,

As the Data Network final exam on 02 August 2023 approaches, here are important details to keep in mind:

• Register for the DN course final exam on LSF before 26 July 2023.
• Only students who successfully passed the midterm (or midterm retake) assignment are eligible for the final exam.
• The exam will take place in three rooms:
  • Günter-Hotz Lecture Hall Building. E2.2
  • Lecture Hall 01 Building E1 3
  • Lecture Hall 02 Building E1 3
  • Lecture Hall 03 Building E1 3
  • We will inform you about your assigned exam room on Monday, 31 July 2023.
• Remember to bring your student ID on the exam day.
• You can enter the room at 9:00 AM; the exam starts at 09:15 AM and lasts for up to 150 minutes.
• You are allowed to bring and use one A4-sized note sheet for the exam. You can use both sides as you like and do with that whatever you want. Paint pictures of flowers on both sides, print in font size 3, and write with finger-paint….use it. Of course, nothing digital! Just paper!

If you cannot register to LSF as an Erasmus student or for any other reason, please email us at inet-teaching@lists.mpi-inf.mpg.de with your name, matriculation number, and the reason as soon as possible.

Good luck with your preparations!

Your DN team

Dear Students,

just a reminder that we are now having our lecture on Internet Governance with experts from RIPE NCC and ICANN fully online here:

https://eu01web.zoom.us/j/61568714489?pwd=WDZTZWQ3WVVCNnRvUUlGLzFEUkFXdz09

I heard rumors from a reliable source that there may be at least some things in the exam related to Internet governance, so we whole hartedly recommend you joining the Zoom session (and asking questions to our speakers!)

With best regards,

Tobais

Dear Students,

during tomorrow's online only lecture you have the opportunity to hear how the
Internet-sausage is made from Jelena Cosic (RIPE NCC) and Gabriella Schittek
(ICANN).  The two will first present on how Internet governance works in
practice, and will then be available for questions.

This is a unique opportunity to learn more on the (social) infrastructure that
makes the Internet tick!

We hope to see you all tomorrow in the Zoom room: zoom link. :-)

With best regards,
DN Team

Dear Students,

the course evaluation links for Data Networks 2023 have become available! Please fill both of them (Tutorial and Lecture) out as soon as possible (so you do not forget. ;-))

Lectures: https://qualis.uni-saarland.de/eva/?l=143169&p=ct9tvf

Tutorials: https://qualis.uni-saarland.de/eva/?l=1431691&p=mhihjt

You input is very important for us to refine and improve the course. Even if you feel like you do not have much to add, every single survey response helps us to make DN better every year!

We are looking forward to you responses!

With best regards,

Anja, Oliver, Tobias & the Tutors

Dear Students,
The results for the mid-term retake assignment are available. We graded only up to 35 points, as a passing score for the mid-term assignment, for all those who achieved 35 or higher points.

Unfortunately, students who have not achieved at least 35 points in mid-term retake assignments are not eligible for the Data Networks 2023 final exam.
 
We do not distribute the feedback for the mid-term retake submissions. However, students who got less than 35 points can email us to review their submissions with them jointly.  

Best, 
Your DN Team

Dear Students,

The Midterm assignment re-take is getting closer - Friday, 30th of June, 14:00 CEST.

We would like to remind you that you can solve the midterm assignment either online, 
by downloading a PDF with questions from CMS (https://inet-teaching.mpi-inf.mpg.de/dn_23/dl/38/Midterm_Retake.pdf), or solving it in in-person,
where we will provide printed versions of the assignment for everyone.

Instructions:
 - read carefully all the information on the introduction sheet.
 - make sure that you fill identification information correctly (Name, student ID)
 - you will have 90 minutes at your disposal to solve the assignment (we also took into account the time to download and submit the solution)
 - submit the solution before the deadline! We will not accept any solution after the deadline! (valid for both online and in-person)

If you decided to do the midterm in person:

- you can pick up the printed version of the assignment in Room002, Building E13 (usual lecture room) starting from 14:15.
- you can use any empty seat in the Lecture Room to solve the assignment, you can also take it with you if you wish.
- IMPORTANT, you have to bring back your solution before the deadline! We will not accept any solutions after 15:45. 
- If you pick up the assignment after 14:15, your deadline is still 15:45!

If you decided to do the midterm online:

- you will be able to download the PDF starting from 14:15. (DO NOT ATTEMPT TO DOWNLOAD EARLIER!)
- IMPORTANT - you have to upload your solution before the deadline! We will not accept any solution after deadline(15:45).
- write your solution on the downloaded PDF! (We will not take in consideration submissions that do not follow the required format)
- Your submission will be printed and graded, so make sure that your answers are readable after printing (do not write pdf comments!)
- In case you encounter technical problems with downloading the PDF or uploading your solution please inform us before DEADLINE!
  You can do it via Email (inet-teaching@lists.mpi-inf.mpg.de) with proof of problem!
  In case you have internet issues, please contact via phone: +49 681 9325 3500 (Iris Wagner)
  

Good luck,
DN Team

Dear students,

as discussed in today's lecture, there is a netfluencer called 'tracketpacer' making tiktoks*, youtube videos**, twitter posts***, and an insta channel**** about all things network(engineer)ing.

This might be a more fun way to learn about ethernet (her very special interest) and less boring parts of networking (like how to build a 10gE hub) in a more fun way than listening to me monologing for 90 minutes. ;-)

So, please find the links below:

Main page: https://www.tracketpacer.com/

TikTok: https://www.tiktok.com/@tracketpacer (Where it all started)

YT: https://www.youtube.com/tracketpacer

Insta: https://www.instagram.com/tracketpacer/

Twitter: https://twitter.com/TracketPacer

Co-hosted Podcast: https://podcast.artofnetworkengineering.com/

With best regards,

Tobias

* Of course I/we do not recommend the use of any external, cloud-based, social-media service; Be aware of the privacy implication, click at your own risk, and in case of doubt, use Tor.

** Yes, also not this one.

*** This one neither.

**** Nope, also not. 

Dear Students,

If you have not collected your mid-term assignment containing feedback, you can pick them up on Friday (23.06.2023) after the DN lecture. This is your last chance to pick up the assignment.

To collect your assignment, you must identify yourself with your student ID card!

If you cannot come in person, you can ask a fellow student to pick up your assignment. In this case, Please print the following form and fill it in.
You can pick up the assignment of your fellow student only if you bring along the completed form as well as your student ID.

Best Regards,

Your DN23 Team

Dear students,

We have a few announcements about the upcoming tutorial sessions.

1. Tuesday 27.06, Pascal's Session will be held by Qi.
2. Tuesday 27.06, Fariba's Online Session will be held by Cristi.
3.  Friday 30.06, Florian's Session will be shorter than usual and end at 11:00 CEST.

Best,
DN Team

Dear Students,

we just released the results for the mid-term assignment. As mentioned earlier,
we reduced the passing-grade to 30 points instead of 35.

To get a better idea of how the course is going, we would like to ask you to
fill out our post-grading survey here:

https://nextcloud.init.mpg.de/index.php/apps/forms/q5wzFiM7ZgfGC2MY

To get the assignment feedback, we will provide you the opportunity to pick up you assignment submission
after the lecture this week. No matter if you did the assignment online or in person,
you can pick up the corrected submission containing the feedback after the lectures on Tuesday (20.06.2023) or 
on Friday (23.06.2023).

To pick up the submission you need to identify yourself with your student ID card! - No student ID card == no submission!

You can ask a fellow student to pick up the submission in case you cannot come.
For this, please fill in and print the following form here.
You can pick up the submission of your fellow student only if you have the complete form (and your student ID  card of course)! 

If you are unable to pick-up your assignment, e.g., you are abroad and you do not have a VISA yet, please reach out via email.

If you did not pass the assignment, we invite you to participate in a retake
opportunity:

    - The retake will take place on the 30th of June, in the normal lecture slot,
      again as an online and offline assignment.

    - To remain consistent, the retake will follow the same difficulty gradient
      as the mid-term assignment. We encourage you to prepare for transfer
      questions.

    - The retake will be pass/fail, and it will not be possible to gain 
      'extra credits' in the retake. You will need 35 points to pass!

    - We will be strict about submitting online versions via the official
      channel and will not accept submissions that did not put the answers on
      the supplied PDF. This means no submissions via email or submissions on
      additional sheets.

    - We of course encourage you to use the retake for practice if you already
      passed the first opportunity, but will not accept submissions.

For those that are curious about the point distributions and how they differ for online vs. offline exam takers please see: 

In addition, see figure below for a comparison of those students that registered for tutorials vs. those that did not:

Please reach out to us if you have any additional question.

With best Regards,
The DN23 Team

Dear Students,

we hear that you are all anxious about the results of the mid-term assignment.
We are still busy grading the assignment, but would like to already provide you
with some information along the way. We expect to have the final results with
you on Monday.

From the first set of corrections, we see that the transfer questions
(Q3 and Q4) were challenging to answer, especially within the given timeframe.
Furthermore, there were technical difficulties with the online submissions.

We hence decided:
    - For the first instance of the assignment, we will lower the passing requirement
      to 30 points. This will not be the case for the retake.

    - We offer a re-take opportunity for this assignment if you did not pass.
      the retake will take place in the lecture slot on the 30th of June.

    - The retake will be pass/fail, and it will not be possible to get extra
      credits as with the first `. Hence, if you passed in the first
      assignment, we of course encourage you to participate online in self-practice,
      but ask you to not hand it in.

    - We will try to include more transfer questions in the homework assignments
      for the second half of the course, to also provide more challenging
      practice material closer to what can be expected in graded assessment.

We will also provide a short review of the feedback survey and an overview
analysis of scores and results from the assignment in the beginning of the 
lecture on the 27th.

With best regards,
The DN23 Team

Dear students,

thank you for participating in the midterm assignment!

We would like to know what you thought about the assignment.

No matter if your liked it or not, let us know what we can do better in our survey:

https://nextcloud.init.mpg.de/index.php/apps/forms/gH2pNqcbKbDcrXYs

With best regards,
DN Team!

Dear students,

We are aware of a problem with the CMS, and try to resolve it before the beginning of the exam. 

We will update you via email. 

Please rest assured that you will not experience disadvantages because of this, and we will apply appropriate policy.

In the meantime, please do not refresh the page before 14:15.

with best regards,

DN team

Dear Students,

The Midterm assignment is getting closer - Tuesday, 13th of June, 14:00 CEST.

We would like to remind you that you can solve the midterm assignment either online, 
by downloading a PDF with questions from CMS (https://inet-teaching.mpi-inf.mpg.de/dn_23/dl/28/Midterm.pdf), or solving it in in-person,
where we will provide printed versions of the assignment for everyone.

Instructions:
 - read carefully all the information on the introduction sheet.
 - make sure that you fill identification information correctly (Name, student ID)
 - you will have 90 minutes at your disposal to solve the assignment (we also took into account the time to download and submit the solution)
 - submit the solution before the deadline! We will not accept any solution after the deadline! (valid for both online and in-person)

If you decided to do the midterm in person:

- you can pick up the printed version of the assignment in Room002, Building E13 (usual lecture room) starting from 14:15.
- you can use any empty seat in the Lecture Room to solve the assignment, you can also take it with you if you wish.
- IMPORTANT, you have to bring back your solution before the deadline! We will not accept any solutions after 15:45. 
- If you pick up the assignment after 14:15, your deadline is still 15:45!

If you decided to do the midterm online:

- you will be able to download the PDF starting from 14:15.
- IMPORTANT - you have to upload your solution before the deadline! We will not accept any solution after deadline(15:45).
- write your solution on the downloaded PDF! 
- Your submission will be printed and graded, so make sure that your answers are readable after printing (do not write pdf comments!)
- In case you encounter technical problems with downloading the PDF or uploading your solution please inform us before DEADLINE!
  You can do it via Email (inet-teaching@lists.mpi-inf.mpg.de) with proof of problem!
  In case you have internet issues, please contact via phone: +49 681 9325 3500 (Iris Wagner)
  

Good luck,
DN Team

Dear Students,

in today's tutorial (Tutorial 3, Friday 09.06, 10.00) we discussed the TCP retransmission behavior, and I would like to clarify some points.

If TCP detects a packet loss, the retransmission behavior depends on the implementation of TCP.

The simple Go-back-N implementation, for example, will retransmit the entire available window, starting from the last acknowledged sequence number (as discussed in the tutorial)

TCP Reno on the other hand, will act a bit smarter. It will enter 'fast recovery' mode and only resubmit the lost segment. If there is still space in the sending window left, it will retransmit new segments as allowed. It will NOT resubmit everything from the lost segment onwards. For more details, you can also have a look at the congestion control state machine in Lecture 9, Slide 41.

Have a nice weekend and good luck in the midterm!

Best Regards,
Florian 

Dear Students,

today is a public holiday in Germany.

We acknowledge that the holidays one may or may not celebrate depend on your own cultural background, and with the upcoming mid-term assignment, some of you may wish to nevertheless have a tutorial today.

Qi hence offered to still hold today's tutorial session.

However, to avoid practical problems, today's tutorial session will be online:

You can access the Zoom link here: Qi tutorial Zoom Link (passcode: 759793).

Please understand that attendance is not mandatory, and we respect you (and encourage you to) taking some rest today.

With best regards,

DN Team

Dear Students,

The third voluntary homework is online on the CMS page and is, as usual, due in a week: Tuesday, May 09 at 23:59 CEST.

For this homework, you also need to download additional material from the CMS: Also linked here.

Reminder: Second voluntary homework is due tonight (Tuesday, May 02, 23:59 CEST).

Your INET teaching team

Dear Students,

This is all additional material not required for the exam, but might be interesting for you.

Lecture Tuesday (topic DNS):

https://pure.mpg.de/rest/items/item_3480830_3/component/file_3482426/content - Relevant: Page 19ff, Appendix on DNS Terminology

Lecture Friday (topic EMAIL):

https://pure.mpg.de/rest/items/item_3477431_1/component/file_3477432/content - Relevant: Section 2.1, on the Origins of Systemadministration and the frequency of beards
https://pure.mpg.de/rest/items/item_3384330_6/component/file_3458330/content - Paper on modern email standards
https://www.email-security-scans.org/ - Website to test what your mailserver supports when _sending_ emails.

Best,
Your DN Team

Dear Students, 

We introduce and explain the tutorial organization matters in the first tutorial session. Therefore, you can ask all your organizational-related questions and get introduced to your tutor in this session.

For every homework, we want you first to try and solve them. Then, after the submission deadline of every homework, you will have a detailed explanation and discussion of the homework solution in the follow-up tutorial sessions.  

All the best for your first homework solution! 

Best, 
Your DN Team

Dear Students,

As stated in the 'Voluntary Homework Sheets' section of the CMS page, you can solve up to ten Homework sheets throughout the semester.

Solving homework is not mandatory and will not influence your final grade.

You can submit up to three homework sheets to receive detailed feedback.

We will discuss homework solutions during our tutorial sessions (see schedule in 'Weekly Tutorials' section)

The First assignment is released and the submission deadline is Tuesday, April 25 at 23:59 p.m. CEST

Best Wishes,

Your DN Team

Dear Students,

We added the Zoom links for the tutorial sessions. You can join whichever tutorial you like. During the tutorial sessions, please only unmute yourself to ask a question. For the remainder of the time, please stay muted and disable your video. When you join the sessions you are muted and your video is disabled.

It might happen that you are asked for a password even though the invite includes it. The passcode for the session is: 759793

Dear Students,

We will have the first lecture of the Data Networks course tomorrow (14.04.2023) at 2:00 PM c.t.(2:15PM) in Building E1.3 - Lecture Hall 2(002).
Meanwhile, we encourage you to choose a tutorial session slot of your preference in the CMS system before the first Tutorial session (20.04.2023). 

Note: You can still change your tutorial slot during the semester if the initial choice no longer works for you.

Thank you!

Your DN Team 

Dear Students,

Due to the existing overlap between the Hands-On-Networking course and our course, there are the following regulations with regards to taking both courses:

1. You are _not_ allowed to use both courses as an (compulsory choice) lecture / (Wahlpflicht) Vorlesung. 
2. You are allowed to use Data Networks as an (compulsory-choice) lecture / (Wahlpflicht) Vorlesung while using Hand-on Networking as either a seminar, practical course / Praktika, or as a free-choice module. If you do so, you can get the full 15 Credit Points / ECTS Points for taking both courses.

In case you have any question, do not hesitate to write us an email to inet-teaching@lists.mpi-inf.mpg.de.

Dear Students,

Similar to last year's iteration, Data Networks will be held in person combined with best-effort Zoom virtual sessions and will conclude with a final written exam. The first lecture (also includes organizational matters) will be held on April 14th.

https://eu01web.zoom.us/j/61568714489 (Passcode: 009778)