A. Helmy's picture NOMADS group logo

Ahmed Helmy
Professor
Computer & Information Science & Engineering (CISE) Department
Founder and Director: Mobile Networking Laboratory (NOMADS group)
College of Engineering, University of Florida
Gainesville, FL 32611
email: helmy at ufl.edu

CNT 5106 C Computer Networks: Fall 2014 - (Announcements) - (Homeworks) - (Instructor's Website) - (Syllabus )

- "Understanding the Design and analysis of the Internet" -

Lecture Slides

(Please check the reading materials links below for related readings and references. Slides and topics subject to update throughout the semester. The initial set of slides may be from an earlier offering, but will be updated as/if/when needed.)
  1. [Aug 26] Chapter 1 on Overview and Introduction to the Internet. (Updated Sept 2: updated slides.)
  2. [Sep 2] Chapter 2 Application layer and protocols.
  3. [Sep 23] Chapter 3 Transport layer and protocols.
  4. [Oct 9] Chapter 5 Data Link Layer and MAC protocols.
  5. [Oct 9] Chapter 6 Wireless and Mobile Networking (plus TCP over ATM).
  6. [Oct 28] Review:
  7. [Nov 18] Chapter 4 Network Layer Intro.
  8. [Nov 18] Multicast Routing (I)
  9. [Nov 18] Multicast Routing (II): Protocols, Mbone and Deployment issues

Announcements:(in reverse chronological order)

  1. - [Dec 13] The final exam is planned on Dec 18th (Thursday) from 3-5pm. It will be conducted in NEB in the lecture room (another room nearby will be arranged soon. An announcement will be made when it is finalized.). The final exam will carry 40% of the total grade and will cover the second half of the semester (including data link layer, TCP over ATM, wireless/mobile networking, network layer, and multicast routing. The format is somewhat similar to the midterm, with thinking-based questions that do not require much writing. The exam is closed books and closed notes. A sheet at the end of the test will include all the needed formulae (and more). Good luck!
  2. - [Dec 13] The sheet of formulae (to be included in your final exam) is on-line at Sakai (under announcements).
  3. - [Dec 13] Hwk 4 solution is on-line (through Sakai).
  4. - [Dec 6] Hwk 3 solution is on-line (through Sakai).
  5. - [Dec 5] Dear class, The course and instructor evaluations for the CNT5106C computer networks class are open on-line and you can access them through https://evaluations.ufl.edu [log in using your gatorlink account]. We appreciate your feedback on the course's strengths and weaknesses so we can improve in the future. The computer networks team (instructor and TAs) wish you success and we hope that you have benefited greatly from this course. Good luck! Regards, -AH for the CNT5206C fall 2014 team.
  6. - [Dec 3] The TAs have added a few more office hours this week to answer any questions from the students regarding the midterm. The TAs shall be available for two hours on Friday Dec 5, at 10am-12pm in E309. The instructor will hold regular office hours on the coming Thursday and Tuesday.
  7. - [Dec 2] Homework 4 is online now (in Sakai). Due Dec 12th (11:55pm).
  8. - [Nov 19] Homework 3 is online now (in Sakai) and will be due on Dec 2nd, just before midnight (11:55pm). It covers the data link layer, wireless networking, and TCP over ATM. It has 20 extra points.
  9. - [Nov 18] Clarification regarding grading and extra credit: All the extra credit (in the homework and the midterm exam) will count and will be added to your total grades in the end. This is not clear from Sakai, as it has its limitations when deadling with extra credit. But Sakai does not determine your final grade, the course-team members do through careful consideration of all your credits. So please do not worry about that! Good luck to all!
  10. - [Oct 28] Today's lecture will include quick/brief review of the first 3 chapters, covering the chapters that will be included in the midterm. The slides for the review have been posted above.
  11. - [Oct 28] The final page of the midterm exam (with the formulae/equations) is posted here. Please familiarize yourself with it, in case you need to use some of these equations. Also please print and bring these equations to the midterm exam. This is the only printed material you will be allowed in the exam. [For the off-campus/Edge students, you should not bring any printed material with you as this will be provided for you within the exam itself.]
  12. - Exam dates: Midterm exam Oct 30th (Thursday) 1:55-3:50 [regular lecture hours]. Final exam Dec 18th (Thursday) 3-5pm. More information to be provided later on. Also the syllabus has been updated to reflect these dates.
  13. - [Oct 12] Homework 2 (including Wireshark experiment) is posted on-line.
  14. - [Sep 30] A small fix/typo in Hwk1 in Q19: "Which peer is not its first successor?" the word 'not' should be 'now', so the correct wording of that part of Q19 should be: "Which peer is now its first successor?"
  15. - [Sep 28] TA office hours are: Soham Das (soham@ufl.edu): Wednesdays 10-12AM in office E528, Nakul Jindal (nakul02@ufl.edu) Monday 1-3PM in office E362, Michael Retherford (mretherford@ufl.edu) Tuesday 11:50am-1:50pm in office E309.
  16. - [Sep 23] Homework 1 is posted on the e-learning website (Sakai) [here is a link]. Homework 1 covers chapter 1 (Internet Architecture) and chapter 2 (Application Layer), and is due on Oct 2nd (Thursday) at 5pm. Please get a head start on it.
  17. - [Sep 2] Due to research-related travel (to ACM MobiCom for several presentations), I will be out of town next week (Sept 7-12). I have scheduled pre-recording sessions to make up for the lecture times next week. I will be covering the introduction to Chapter 2 in these recording sessions, and they are scheduled as follows:
    • Sep 3, 12:50pm: NEB 201 (our normal lecture meeting room). [50 min]
    • Sep 3, 4:05pm: NEB 201. [50 min]
    • Sep 4, 12:50pm: NEB 201. [50 min]
    You are welcome to attend if you want, but the lectures will be video recorded and posted on the website as usual.
  18. - [Aug 31] Welcome to the computer networks course for Fall 2014. So much is happening in the networking world these days, from social networks, to emerging mobile networks, unprecedented connectivity and coverage, security/privacy issues, to extremely powerful mobile devices and smartphones. There is so much potential for growth and applications in the future. We will try to build a very solid foundation of design, architecture, and analysis principles and tools to put you in a position to lead in this new connected world. I look forward to taking this journey with you for this semester. Best of luck to all! -A. Helmy

Homeworks

[Note: Please check the annoucements section also for more information. The solutions are posted on the Sakai class webpage.]
  1. - Homework 1 posted on the Sakai website (Click here for the e-learning website). Due Oct 2, 2014 (Thursday).
  2. - Homework 2 (including Wireshark experiment) posted on the Sakai website (Click here for the e-learning website). Due Oct 24, 2014 (Friday, 11:55pm just before midnight).
  3. - [Nov 19] Homework 3 is online now (in Sakai) and will be due on Dec 2nd, just before midnight (11:55pm). It covers the data link layer, wireless networking, and TCP over ATM. It has 20 extra points.
  4. - [Dec 2] Homework 4 is online (Due Dec 12).

Experiments and Labs

Reading materials pointers

  1. The website for the required book by Jim Kurose and Keith Ross can be accessed here or here, then click on student resources.
  2. Particularly interesting are the applets on the above website, as you can experiment with various parameters (of delay, distance, etc.) and observe the network performance and behavior.
  3. Experiment with the following applets from the book's website at this link. Especially the 802.11 CSMA/CA basic applet and the 802.11 CSMA/CA with hidden terminal.
  4. Play the animation for the wireless access protocols through the network animator (nam) [see above to install/run nam].
  5. Videos to show some basic behavior of TCP window mechanism:
    1. Basic window mechanisms (e.g., selective repeat) here.
    2. Slow Start (exponential increase) then congestion avoidance (linear increase) here.
    3. Change of TCP (cwin, ssthresh) parameters here.
  6. Video to show interaction of TCP with routing dynamics: here.
  7. The network animator (nam) [.exe, bin for windows XP], can be used with the following scripts: selective repeat (or TCP without slow start), Self Clocking, TCP with Slow Start, TCP with slow start (scenario 2), TCP with fast retransmit mechanism, TCP with routing dynamics.
  8. Light reading on elementary queuing theory: Basics, M/M/1 model.
  9. Snap shots of Google Earth files obtained using Wififofum and other wireless signal measurements around Gainesville (pic 1, pic 2).
    animation of clustered behavioral profiles in mobile networks (video)
  10. Some resources for multicast, specifically the Protocol Independent Multicast (PIM). Recommended initial readings: From the PIM-SM Spec sections 1 & 2, and the Bootstrap mechanism for dynamic Rendezvous Point (RP) election sections I, II and IV A. Once you are done with the initial reading, if interested, you can read the rest of the documents and also the PIM architecture paper, before others.
  11. For those interested in research, a small (potentially helpful) note: How to start research? (A personal note for networking students)
Office Hours: Prof. office hours are: 10-11AM Tues/Thurs in CSE426.
TA office hours are: Soham Das (soham@ufl.edu): Wednesdays 10-12AM in office E528, Nakul Jindal (nakul02@ufl.edu) Monday 1-3PM in office E362, Michael Retherford (mretherford@ufl.edu) Tuesday 11:50am-1:50pm in office E309.
[Office hours may vary, watch for potential occasional updates. If you can't come to the above office hours send me email and I'll setup an appointment at another time for you.]