Many of the problem assignments are from the course textbook:

Buy at Amazon Bertsekas, Dimitri, and Robert Gallager. Data Networks (2nd Edition). Upper Saddle River, NJ: Prentice Hall, 1991. ISBN: 0132009161.

The relevant reading assignments for each problem set are also from the textbook.

Problem Set Files
1 (PDF)
2 (PDF)
3 (PDF)
4 (PDF)
5 (PDF)
6 (PDF)
7 (PDF)