EE323: Computer Networks

Course Info

Instructor: Prof. Sung-Ju Lee (, N1 #306
TAs: HyungJun Yoon, Hyeongheon Cha, Ryuhaerang Choi, Sujin Han, Yewon Eliana Kim, Taeckyung Lee, Adiba Orzikulova
When: Tue/Thu 14:30-16:00
Where: Hybrid Class [Offline (N1 #111)] [Online (Zoom link)]
Class website:
KLMS page:
Class email:
Campuswire page:
Course registration:
Office hours: Office hour reservation link
Career Development Interviews: Ask questions here


  • This class will be hybrid and run live over Zoom. We will also record the lectures and upload the video.

  • Class Overview

    The Internet is profoundly changing the way we conduct business, communicate socially, or find information for entertainment. In this course, we learn the fundamental concepts and principles that shape modern computer networks, understand how the Internet is designed and is being operated in practice, and think about the current issues. Class content is introduced top-down, starting with the applications that are most familiar to students, such as the Web and e-mail, before delving into lower-level details. Students gain a hands-on perspective by writing their own simplified versions of popular Internet protocols.


    • Programming Structure for Electrical Engineering (EE209 or equivalent)
    • Basic programming skills in C
    • Commitment, energy, and enthusiasm to learn


    Computer Networking: A Top-Down Approach (7th ed.)
    by Jim Kurose and Keith Ross

    Grading Policy

    Exam & Quizzes 40 Short quizzes at the beginning of each class (starting on March 15th) and the final exam on June 16 (Thu); No midterm exam.
    Homework 20 Problem exercises and short essays.
    Projects 30 4 Programming assignments. Details will be guided in lab sessions within classes.
    Contribution 10 This course would be successful only when it's interactive. Students are highly encouraged to ask questions, present their opinion, and lead discussions during classes and in Campuswire


    • 6/19 Solutions and grading criteria for the final are out here.
      The offline claim session will be held from 15:00 to 16:00 on 6/21 (Tue) in N1 #111.
      If you are not available at that time, we will schedule a personal session by appointment.
      Please email to schedule the appointment.
    • 4/21 Hybrid Class Starts from May 10th (Tue)
      We will operate a hybrid class starting from May 10th (Tue). Until May 10th, we only have Online classes.
      Note that only students who got COVID and/or are not in Korea can attend classes Online.
      Students other than the cases above should attend Offline classes (N1 #111).
      Expect to meet you in person! :)
    • 4/5 Career Development Interviews: Han Hee Song (Apple)
      Ask questions to the professionals of computer networks!
      You can submit questions by i) typing, or ii) uploading a video of yourself asking questions.
      For more information, please visit here.
    • 3/26 Update on class contents this week:
      To leave enough time for lab session #2 and Q&A for the lab, the lecture on Tuesday (3/29) will cover up to TCP segment structure (up to and including 3.5.3).
      Thursday's lecture will be pre-recorded and the lecture video will be released after the quiz. The contents will be from 3.5.4 to 3.8.
    • 3/22 Career Development Interviews:
      Ask questions to the professionals of computer networks!
      You can submit questions by i) typing, or ii) uploading a video of yourself asking questions.
      For more information, please visit here.
    • 3/15 Instructions for Quiz:
      1) Don't be late; the link shown on the course website at 2:30PM sharp.
      2) One question; you won't have much time (typically 2-3 minutes)
      3) After completing the quiz, join Zoom; lecture will start around 2:35PM
    • 3/10 Until further notice, and at least until the end of March, we will keep the online lecture format.
    • 3/8 Note that the Zoom meeting for Lab #1 is different from the Zoom meeting for the usual classes.
      Please attend the Lab #1 via the following link;
    • 3/3 Welcome to EE323! If you're ready to take this course, please do the following:
      1) Submit this form ( to get access to course materials
      2) Join our Campuswire group (password: 6611) for class discussions
    • 3/3 Instructions for making Second Chance video:
      1) You should first be confirmed as a preview presenter from the professor.
      2) Please follow the instructions until Chapter 2 as instructed in this file.
      3) Send us the video via the course email (
    • 3/3 This course is a Hybrid Class. Please follow instructions below:
      1) Until the classroom (N1 #111) is completely set up for providing a Hybrid class, the class will be on ZOOM ONLY.
      2) After completing the setup, you SHOULD attend the class OFFLINE (N1 #111). You can go online ONLY when you should quarantine.
      3) In the classroom, you should clean your seat with provided sanitizer before class, wear a mask, and sit one seat apart from each other.


    Week Date Class / Assignment Quiz Preview Required reading Submission
    1 3/3 Thu Class overview [slides] [video]
    2 3/8 Tue Internet, edge, core [slides] [video] 1.1, 1.2, 1.3
    3/9 Wed Due: Homework #1 [slide] Submit
    3/10 Thu Lab #1 [Zoom Link] [slides] [video]
    3 3/15 Tue Delay, loss, throughput, protocol layers, security, history [slides] [video] Link 1.4, 1.5, 1.6, 1.7
    3/17 Thu Network applications, web, HTTP, email [slides] [video] Link 2.1, 2.2, 2.3
    4 3/22 Tue DNS, p2p, CDN, socket [slides] [video] Link 2.4, 2.5, 2.6, 2.7
    3/23 Wed Due: Project #1 [document] Submit
    3/24 Thu Transport, UDP, reliable data transfer [slides] [video] Link 3.1, 3.2, 3.3, 3.4
    5 3/29 Tue TCP [slides] [video] Link Seunghyun Ahn 3.5
    Lab #2 [slides] [video]
    Due: Homework#2 [slides] Submit
    Due: Ask questions to Lara Deek Submit
    3/31 Thu Congestion control [slides] [video] Link 3.6, 3.7
    6 4/5 Tue Network layer, router, scheduling [slides] [video] Link 4.1, 4.2
    4/7 Thu IP, forwarding, SDN [slides] [video] Link Jehun Kang 4.3, 4.4
    7 4/11 Mon Due: Project #2 [document] Submit
    4/12 Tue Routing protocols [slides] [video] Link 5.1, 5.2
    Due: Ask questions to Han Hee Song Submit
    4/14 Thu OSPF, BGP [slides] [video] Link 5.3, 5.4
    8 4/19 Tue Midterm week
    4/21 Thu Midterm week
    9 4/25 Mon Due: Homework #3 [document in pdf extension and doc extension] Submit
    4/26 Tue Lab #3 [slides] [video]
    (video includes the interview highlights with Dr. Lara Deek)
    4/28 Thu SDN control plane, ICMP, SNMP [slides] Link 5.5, 5.6, 5.7
    10 5/3 Tue Link layer, error detection & correction, multiple access [slides] [video] Link 6.1, 6.2, 6.3
    5/5 Thu No class. Holiday
    11 5/10 Tue ARP, Ethernet [slides] [video] Link 6.4, 6.5
    5/12 Thu VLAN, MPLS, datacenter [slides] [video] Link 6.6, 6.7
    12 5/16 Mon Due: Project #3 [document] Submit
    5/17 Tue Lab #4 [slides] [video]
    5/19 Thu Wireless, Wi-Fi [slides] [video] Link 7.1, 7.2, 7.3
    13 5/24 Tue Cellular, mobility, mobile IP [slides] [video] Link 7.4, 7.5, 7.6, 7.7, 7.8
    5/26 Thu Multimedia, streaming, VoIP [slides] [video] Link Jehun Kang 9.1, 9.2, 9.3
    14 5/31 Tue RTP, SIP, QoS [slides] [video] Link 9.4, 9.5
    6/2 Thu Security, encryption, authentication, Digital signature [slides] [video] Link 8.1, 8.2, 8.3
    15 6/6 Mon Due: Project #4 [document] Submit
    6/7 Tue SSL, IPSec [slides] [video] Link 8.4, 8.5, 8.6
    6/9 Thu WLAN security, firewall, IDS. [slides] [video] Link Woomin Song 8.7, 8.8
    16 6/14 Tue Finals week
    6/16 Thu Finals week

    Class Policy

    Students are encouraged to interact with classmates, as well as the professor and the TAs, to discuss course material and assignment problems. In all your writing, including homework, essays, reports, and exams, use your own words, and acknowledge the source if you use someone else’s slides, quotes, figures, text, etc. Plagiarism and cheating are serious offenses and will be punished by failure on exams/assignments/course, and suspension or expulsion from the University.