A. Helmy's picture NOMADS group logo

Ahmed Helmy
Professor & Graduate Coordinator
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 4007 C Computer Networks Fundamentals: Fall 2015 - (Announcements) - (Homeworks) - (Instructor's Website) - (Syllabus) - (Course Evaluations)

- "Introduction to 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: Overview and Introduction to the Internet.
  2. [Sep 1] Chapter 2: Application layer and protocols.
  3. [Sep 23] Chapter 3: Transport layer and protocols.
  4. [Oct 9] Chapter 5: Data Link Layer, MAC protocols, and Local Area Networks (LANs).
  5. [Oct 26] Review:
  6. [Nov 2] Chapter 6: Wireless and Mobile Networking (plus TCP over ATM).
  7. [Nov 18] Chapter 4 Network Layer Intro & Unicast Routing
  8. [Dec 2] Chapter 4 Summary & Review.
  9. [Dec 2] Multicast Routing Algorithms & Protocols (Intro)
  10. [Dec 2] Chapter 6 Review.
  11. [Dec 2] Chapter 5 Review.

Announcements:(in reverse chronological order)

  1. - The final exam on Dec 18th (Friday) will be held in the same room as the lecture at Turlington Hall (TUR L011) from 7:30-9:30am.
  2. - Course evaluations shall close on Dec 11, please complete the course evaluations at evaluations.ufl.edu as soon as possible. Thanks!
  3. - The first option for the final exam has been conducted successfully. The rest of the class shall take the final exam on Dec 18th, 7:30-9:30am according to the formal schedule of UF exams. More information to follow.
  4. - Solution for Hwk4 is posted on the Sakai webpage for class.
  5. - [Dec 2] Instructor evaluations are open now at evaluations.ufl.edu. So please enter your evaluations on-line [they are anonymous and not visible until the end of the semester]. Only 5 students have entered the evaluations so far, but the response should be much higher. [Evaluations open: Nov 24. Evaluations close: Dec 11. Evaluations available to the instructor: Dec 24].
  6. - [Dec 2] Final exam details: the first choice for the exam date is Dec 9th (Time: 8:20pm-10:00pm, Room: FLG0210 (Florida Gym) [~3min walk from Turlington, next to (east of) the Football stadium]). The format will be similar to the mid-term (including short-answer questions, calculation questions and design questions). There will be a sheet of formulas at the end of the final exam paper (shown here). The exam will be closed book and closed notes with focus on basic knowledge and understanding of concepts, and the ability to apply the concepts to calculation and design problems (rather than memorization). You can use a simple calculator, and please bring your UF ID with you and show it to the proctors (instructor & TAs, as available).
  7. - [Dec 2] The TAs put a survey on Sakai to register for either one of the final exam dates (either Dec 9th, or Dec 18th). Please fill it out so we know who is taking the exam on which date, and get estimates of numbers of students taking the test on each day. Thanks!
  8. - [Dec 2] The final exam will focus on the 2nd half of the semester including the data-link layer (including MAC protocols/algorithms, utilization, CSMA variants), wireless and mobile networks (including hidden terminal problem, 802.11, multiple access and CDMA, mobile IP), and network layer (including forwarding, addressing & prefixing (CIDR), routing algorithms (DV & RIP, LS & OSPF), BGP, NAT, multicast routing, the rendezvous problem, PIM, DVMRP). You are expected to know what was discussed in class, lecture videos & slides, and homeworks.
  9. - [Nov 30] Information about the final exam. You have the option to take the exam at either of two dates: 1- Dec 9th, or 2- Dec 18th. More information to follow.
  10. - [Nov 28] Homework 3 solution example is now posted on-line [under the homeworks section below].
  11. - [Nov 26] Homework 4 (covering the network layer, unicast routing algorithms and IP multicast routing) is on-line now. Due date is Dec 7th (Mon) during TA office hours.
  12. - [Nov 22] Instructor office hours on Tuesday Nov. 24th are moved until after class [11:30-12:30].
  13. - [Nov 12] Homework 3 (covering data-link layer, MAC protocols, mobile and wireless networks) is on-line now. Due date is Nov. 24th (Tues) during TA office hours.
  14. - [Nov 12] Midterm exam grades are available on-line through Sakai.
  15. - [Oct 26] Lecture of Oct 27th will be review for the first 3 chapters.
  16. - [Oct 26] Suggestions on how to study for the midterm exam (this is only a suggestion but each student should pick the system that fits his/her needs):
    1. Start from your own lecture notes (that you took during class and in-class discussions).
    2. Go over the lecture slides and see the videos as/if needed.
    3. Go to the book (but only as a reference) to check details that may not be clear to you from 1 & 2, as/if needed.
      4. Remember you are expected to know what was discussed in class, and not what is in the book necessarily. There is material in the book that was not covered in class, and there is material that was covered in class that is not in the book.
    4. Check your homework solutions and the example solutions. Although you will not get similar time at the exam as you did for the homework, the homework gives indication to some important points that you need to be aware of. If you solve the homework on your own always, you will be in a much better shape in the exam!
    5. Ask questions if things are unclear to you (to the instructor and/or TAs during office hours, or through email). Also, you can ask classmates and have study groups.
    6. Read the questions and instructions on the exam carefully and budget your time accordingly. Do not write too much, but write enough details to convey your ideas (be brief and to the point), and do not exceed the space given for writing (if you do so, then you’re writing too much!).
    7. Bring your ID, pen and simple calculator to the exam. It is closed book, but you will get a sheet / page with the formulas you need and more.
    Good luck to you all, and let your efforts show!
  17. - [Oct 22] Last page of the midterm is here.
  18. - [Oct 15] The first exam for the semester (the midterm exam) is planned to take place on Oct 29th (Thursday) in the same lecture Hall. The exam will be closed book and closed notes, but you will get a formulae sheet at the end of the exam paper with all the equations that you need and more. The sheet will be posted on-line at least a week before the exam so you can become familiar with it. You can bring a pen and 'simple' calculator with you. Please bring your picture ID too. The exam will cover all the material discussed in class and in the homeworks (with the exception of the WireShark Labs) up to and including Chapter 3. So the topics covered include: 1- introduction and architecture of the Internet (protocol stack, hierarchy, etc.), 2- the application layer, communication paradigms and protocols, and 3- the transport layer (including congestion, congestion and flow control mechanisms, TCP & UDP protocols, TCP algorithms, TCP dynamics, and ATM ABR rate adaptation).
  19. - [Oct 12] Homework 1 (part I) grading is done. Students can pick up the graded homeworks from the TA Kingshuk on Wed. during his office hours.
  20. - [Oct 11] Homework 2 and Lab 2 are posted (Please check the Homeworks section and the Lab section for more details).
  21. - [Oct 11] One of the teaching assistants (Babak) will not be holding office hours this week on Tues/Thurs, and instead will hold extra office hours next week. The instructor's office hours and the main TA's office hours (of Kingshuk) will be held as usual.
  22. - [Oct 5] Homework 1 example solution and Lab 1 example solution are posted (see the homework and lab sections below).
  23. - [Sept 28] Homework 1 - Part II is now posted (check Experiments - Lab I section below). [Due Oct 6th during TA ofc hrs]
  24. - [Sept 23] Chapter 3 slides (for the transport layer and congestion control) are posted.
  25. - [Sept 23] Office hours on Thursday morning are not going to be held. But other office hours during the week should be held according to schedule (at the bottom of this page).
  26. - [Sept 22] Homework 1 (part I) is now posted.
  27. - [Sept 3] The lectures are recorded (video). Here is the link for the Lecture Video Recordings (you will need to use your gatorlink account to view the videos).
  28. - [Aug 26] Welcome to the computer networks fundamentals course for Fall 2015. 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 provide a meaningful and clear introduction as well as 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

  1. - Homework 1: Homework 1 - Part I.
  2. - Homework 1 (part II): See 'Lab I' under the Experiments and Labs section below.
  3. - Homework 1 Solution Example (Part I).
  4. - Homework 2: Homework 2 (on transport layer, congestion, congestion control, TCP, ATM ABR.
  5. - Homework 2 Solution Example (Part I, Lab 2).
  6. - Homework 3: Homework 3.
  7. - Homework 3 Solution Example: Homework 3 Solution.
  8. - Homework 4: Homework 4.

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)
Class Meetings: Tuesdays 10:40AM-11:30AM, Thursdays 10:40AM-12:35PM (10:40-11:30, 11:45-12:35) in Turlington Hall (TUR) L011.
Office Hours: Prof. office hours are: 9-10AM Tues/Thurs in CSE426.
TA office hours: Babak Alipour (babak.ap@ufl.edu) Tues/Thurs 12:35-1:35pm, Kingshuk Mukherjee (kingshuk@cise.ufl.edu) Monday, Wednesday, Friday 11:30am-12:45pm. The TA hours will be held in CSE 309.
[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.]