Modern society across the world is becoming increasingly dependent on communication networks. We depend on them for the smooth operation of economic and social activities. This course examines networks as the means of interconnecting devices so that two-way communication is possible. It examines protocols like HTTP, TCP/IP and ATM as well as the OSI reference model, and provides an overview of the topic for learners who have no significant prior knowledge of the subject. The main topics covered in this course are: Internet protocol (IP), the Open Systems Interconnection (OSI) model, Transmission Control Protocol (TCP), Hypertext transfer protocol (HTTP), and Asynchronous Transfer Mode (ATM). Areas that are also covered include the layers of communication, vertical and horizontal communication, protocol architecture, Domain name system, the ATM layers, and an analysis of IP over ATM. This course will be of interest to professionals who work in information technology, network design, and network management, and will also be of interest to students who would like a greater understanding of how networks function.