• Unit 2: The Basics of Protocols

    In life, protocols define the way we interact with other people – for example, the way we behave in a public place. In computer science, protocols are formal sets of rules that dictate the ways in which computers communicate with one another over a network medium. Protocols constitute the backbone of networking. The standard model for networking protocols and distributed applications is the International Standard Organization's Open System Interconnect (ISO/OSI) model. The Internet protocol stack TCP/IP (Transmission Control Protocol/Internet Protocol) model presents a group of protocols optimized for inter-computer communications and in particular for communications between multiple applications that may run on one computer. This unit provides an overview of the TCP/IP stack and its different layers, identifies the function of each layer, introduces the basics of how computers talk to one another in cyberspace using TCP/IP protocols, describes the techniques for wide area networks, and discusses common transmission media for the Internet.

    Completing this unit should take you approximately 2 hours.

    • Upon successful completion of this unit, you will be able to:

      • list and describe each of the layers in the Open Systems Interconnection (OSI) model and the TCP/IP model; and
      • differentiate between all the protocols in the TCP/IP reference model.

    • 2.1: TCP/IP Reference Model

      • The Internetworking Problem Page

        Read these lecture notes. As you read, pay special attention to the history and different versions of internetworking structure based on TCP/IP protocols.

    • 2.2: Open Systems Interconnect (OSI) Reference Model

      • The OSI Reference Model Page

        As you read these sections, consider the following questions: Which came first, the OSI model or the TCP/IP model? Which layers in the OSI model appear to be missing in the TCP/IP stack? Where are they in the TCP/IP model?

    • Unit 2 Assessment

      • Unit 2 Assessment Quiz
        Receive a grade

        Take this assessment to see how well you understood this unit.

        • This assessment does not count towards your grade. It is just for practice!
        • You will see the correct answers when you submit your answers. Use this to help you study for the final exam!
        • You can take this assessment as many times as you want, whenever you want.