Laboratories for data communications and computer networks

In this paper we describe a hands-on laboratory oriented instructional package that we have developed for data communications and networking. The package consists of a software tool, together with instructional material for a laboratory based networking curriculum. The software is based on a simulation environment that enables the student to experiment with various networking protocols, on an easy to use graphical user interface (GUI). Data message flows, packet losses, control/routing message flows, virtual circuit setups, link failures, bit errors etc., are some of the features that can be visualized in this environment. The student can also modify the networking components provided, as well as add new components using the C programming language. The instructional material consists of a set of laboratory exercises for flow and error control (HDLC), IEEE 802.3 CSMA/CD protocol, the token ring protocol, interconnecting LANs via bridges, TCP congestion avoidance and control, IP fragmentation and reassembly, ATM PNNI routing and ATM policing. The laboratory exercises have facilitated the development of a networking curriculum based on both the traditional computer networking principles, as well as the new technologies in telecommunication networking. The laboratory environment has been used in the networking curriculum at the Ohio State University, and is being piloted at other universities. The entire package is freely available over the Internet.