CS 144: Introduction to Computer Networking

CS 144: Introduction to Computer Networking, Fall 2025

Course basics

Lectures	Mondays, Wednesday, & Fridays 1:30 p.m.–2:20 p.m. in Gates B1
Lab sessions	Wednesdays, 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. (location and duration TBD)
Calendar	Subscribe to the CS144 calendar
Optional course texts	Kaashoek & Saltzer, "Principles of Computer System Design," Chapters 7–8 (Networks & Fault Tolerance) Kurose & Ross, "Computer Networking: A Top-Down Approach" Peterson & Davie, "Computer Networks: A Systems Approach"
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 Discussion	In-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.

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

Week 2 (Sept. 29–Oct. 3)

Mon

Reliability II

Wed

TCP I

Week 3 (Oct. 6–Oct. 9)

Mon

TCP III & Packet Switching I

Week 4 (Oct. 13–Oct. 17)

Mon

Why Congestion Control?

Wed

What Congestion Control?

Fri

How Congestion Control

Week 5 (Oct. 20–Oct. 24)

Wed/Fri

Routing

Week 6 (Oct. 27–Oct. 31)

Fri

The eras tour of home networking