15-441/641 is an introductory course in computer networks. The emphasis will be on the basic performance and engineering tradeoffs in the design and implementation of computer networks. To make the issues more concrete, the class includes several multi-week projects requiring significant design and implementation.

The goal is for students to learn not only what computer networks are and how they work today, but also why they are designed the way they are and how they are likely to evolve in the future. We will draw examples primarily from the Internet. Topics to be covered include: congestion/flow/error control, routing, addressing, naming, multi-casting, switching, internetworking, and network security. Evaluation is based on homework assignments, the projects, one mid-term exam and one final.


"Introduction to Computer Systems" is a prerequisite for the course. It is offered under the following course numbers 15-213, 18-213, and 15-513. Graduate students must get a B to satisfy the prerequisite. Students who have taken the prerequisite course at CMU get priority when we move students from the waiting list.

Once student who meet the prerequisites have been cleared, we will consider students with a strong systems background. These decisions will be made in the first or second week of the semester. Do not send mail to the instructors about this (e.g., explaining your background) - it will not help your case.

Course Staff


NameEmailOfficeOffice Hours
Prof Justine Sherry THE INTERNET Mondays and Fridays, Click to Schedule
Prof Peter Steenkiste See Canvas Open office hours: Mon 11-noon; Wed 10-11am
By appointment: Th 1:30-3pm; Fr 4-5pm
See Canvas for Zoom and reservation links

Teaching Assistants

NameEmailOfficeOffice Hours
Christopher Canel Zoom Friday, 11am-12pm ET and by appointment
Ron He Zoom Monday, 2-3pm ET
Wuwei Lin Zoom Tuesday, 5-6pm ET
Zhenzhen Liu Zoom Tuesday, 6-7pm ET
Pengyun Zhao Zoom Tuesday, 9-10pm ET & Wednesday, 2-3pm ET

Course Administrator

Mrs. Tracy Farbacher