This is a series of laboratory exercises designed for use in data communication, computer networking and telecommunication courses. These labs enable students to experiment with various communication protocols and concepts using a workstation, a PC or a network of workstations. The students are able to design protocols, implement them in a simulation environment and graphically and quantitatively analyze their performance. The software is available for free download and runs on HP workstations, Sun Workstations, and PCs with UNIX, Linux, or windows operating systems. This project was funded by NSF CISE Educational Infrastructure.