CS 144: Introduction to Computer Networking, Fall 2025

Course info

Course basics

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