Using Postal Mail System to Teach Packet Switching in Computer Networks

In this paper, we propose an approach to use postal mail system to teach computer networking communication. From many years of teaching computer networking class in college, we found that most students are hard to understand some key concepts well in computer networking communication, such as packet, encapsulation, packet switching vs. circuit switching, routing, IP address, and MAC address. We explored to use postal mail system, esp. how a letter travels, to help students understand packet switching in computer network, and received positive feedback. In this paper, we first modeling postal mail system and packet switching computer network, then compare the two systems in terms of layering design, communication architecture, packet encapsulation, IP address, packet routing, datalink layer delivery, and AS. The whole idea is to help college students learn computer networking by referring to a real world system which can be easily understood.