CS 144: Introduction to Computer Networking, Fall 2025

Course info

Course basics

LecturesMondays, Wednesday, & Fridays 1:30 p.m.–2:20 p.m. in Gates B1 Lab sessionsWednesdays, 7:30 p.m.–10 p.m. in STLC 114 Exams
  • Midterm: in class (replacing week 6 lab session): Wednesday, October 29, 7:30–9 p.m. (location Hewlett 200)
    • Final: Wednesday, December 10, 3:30 p.m.–5:00 p.m. (location Cemex Auditorium) Calendar Subscribe to the CS144 calendar Optional course texts Practice exams
  • Midterm (2021 Fall) Midterm Answer (2021 Fall)
  • Midterm (2023 Spring) Midterm Answer (2023 Spring)
  • Final (2021 Fall) Final Answer (2021 Fall)
    • Final (2023 Spring) Final Answer (2023 Spring) Contact To contact the course staff, please use Ed, the lab sessions, or office hours. You can also email the instructor—I'm here to help but also often behind on email! Accommodations for Disabilities Please use the submission form to submit OAE letters. Please don't send these via email or Ed. Syllabus/logistics Syllabus/logistics handout Ed CS144 on Ed. Please make public posts when possible so answers can benefit anybody. Please don't post source code to lab solutions. Gradescope We use Gradescope for assignment submission and grading. The Gradescope entry code is 3X8XE2. Office Hours CS144 Office Hours Queue. Please use the class calendar at the bottom of the page for the OH schedule. Lecture videos (current year and archived 2024)Canvas Panopto Course Videos Honor Code DiscussionIn-class discussion of permissible collaboration

    Lecturer

    Keith Winstein

    Email: Winstein email address

    Course Assistants

    Naomi Boneh
    naomicyb

    Sureen Heer
    sureen

    Majd Nasra
    mnasra

    Keely Podosin
    kpodosin

    Cary Xiao
    caryxiao

    Damian Ho
    xho

    Lab Assignment

    FAQ Answers to common questions about lab assignment.

    Checkpoint 0: networking warmup
    Out: September 22, due September 28, 11:59 p.m.
    Checkpoint 1: stitching substrings into a byte stream
    Out: September 24, due October 5, 11:59 p.m.
    Checkpoint 2: the TCP receiver
    Out: October 4, due October 12, 11:59 p.m.
    Checkpoint 3: the TCP sender
    Out: October 12, due October 19, 11:59 p.m.
    Checkpoint 4: measuring the real world
    Out: October 12, due October 26, 11:59 p.m.
    Checkpoint 5: down the stack (the network interface)
    Out: November 2, due November 9, 11:59 p.m.
    Checkpoint 6: building an IP router
    Out: November 3, due November 16, 11:59 p.m.
    Checkpoint 7: making an Internet + something creative!
    Out: November 17, due December 5, 11:59 p.m.

    Lecture Notes

    Week 1 (Sept. 22–28)
    Mon
    Course intro Stuff you should know about CS144
    Wed
    Datagrams, encapsulation, and multiplexing
    Fri
    Reliability from unreliability Slides Lecture notes
    Week 2 (Sept. 29–Oct. 3)
    Mon
    Reliability II
    Wed
    TCP I Slides Lecture notes
    Week 3 (Oct. 6–Oct. 9)
    Mon
    TCP III & Packet Switching I Slides Lecture notes
    Week 4 (Oct. 13–Oct. 17)
    Mon
    Why Congestion Control? Slides Lecture notes
    Wed
    What Congestion Control? Slides Lecture notes
    Fri
    How Congestion Control Slides
    Week 5 (Oct. 20–Oct. 24)
    Wed/Fri
    Routing Slides
    Week 6 (Oct. 27–Oct. 31)
    Fri
    The eras tour of home networking Lecture notes
    Week 7 (Nov. 3–Nov. 7)
    Fri
    The eras tour of home networking II Lecture notes
    Week 8 (Nov. 10–Nov. 14)
    Mon
    Elastic Buffers Lecture notes
    Week 10 (Dec. 1–Dec. 5)
    Mon
    Internet security history Slides
    Wed
    Internet security Lecture notes

    Schedule