CS455 Computer Communications and Networking

Monday 4:30 - 7:10 PM, Innovation Hall 134

Instructor: Dr. Songqing Chen
Office: 5319 Engineering Building
Phone: 703-993-3176
E-mail: sqchen AT cs dot gmu dot edu
Office Hours: Wednesday 2:00 p.m. - 3:00 p.m, or by appointment
Course Homepage: http://www.cs.gmu.edu/~sqchen/courses/CS455S19


The course will present data communications fundamentals and computer networking methods, using the ISO 7-layer reference model to organize the study. Attention will be focused on the protocols of the physical, data link control, network, and transport layers, for local and wide area networks. Emphasis will be given to the Internet Protocol Suite. Some advanced topics, such as network security and multimedia networking, will also be covered. Homework and programming assignments will help the students learn how the Internet works and how to design and implement Internet applications.


Grade of C or better in STAT 344, CS 310 and CS 367.




  1. Explain basic electrical engineering principles that enable communication at the physical layer
  2. Demonstrate an understanding of wired and wireless data link layer protocols for shared medium and point-to-point communication
  3. Demonstrate an understanding of the graph theory concepts required for unicast and multicast routing
  4. Demonstrate an understanding of distributed routing protocols
  5. Describe how protocols and applications use ARQ algorithms for distributed reliability
  6. Demonstrate an understanding of end-to-end transport layer protocols
  7. Explain basic concepts in cryptography and networking security protocols
  8. Illustrate fundamental understanding of networking by programming portions of the entire network stack
  9. Demonstrate a basic understanding of performance analysis for computer networking
  10. Demonstrate a basic working vocabulary of data communications and networking terminology


Homework and project assignments are on a semi-regular basis. Both homework assignments and projects are individual efforts. The official platform for projects is site-unix, meaning that the TA will grade your projects on that platform. Currently, site-unix points to zeus.ite.gmu.edu.



Your grade will be calcuated as follows:

No credit if your project does not compile. Late home assignments/projects lose 20% credit and will not be accepted 3 days after due, unless under prearranged conditions.

The final exam will be held on Monday, May 13th, 4:30 - 7:15 PM. Tentatively, the midterm exam will be held on Monday, March 18th, 4:30 - 7:15 PM.

No early exams will be given. Missed/make-up exams are strongly discouraged and must be arranged with the instructor BEFORE the exam date with an official and verifiable excuse.


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Dr. Songqing Chen, Dept. of Computer Science, George Mason University