• Unit 2: The Basics of Protocols

    In life, protocols define how we interact with others – for example, how we behave in a public place. In computer science, protocols are formal sets of rules that dictate how computers communicate with one another over a network medium. Protocols constitute the backbone of networking. The standard networking protocol and distributed application model 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, particularly 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 standard 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:

      • 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 attention to the history and different versions of the 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?

      • OSI Model Page

        This video explores the OSI model and its various layers, which are important in facilitating communication among networked devices. By the end of this presentation, you will be able to recognize and articulate the functions of the seven OSI model layers and understand their sequential order. Be sure to observe how these layers interact to ensure seamless communication.

      • Compare the OSI Model to TCP/IP Page
        After watching this video, you will know the structure of the TCP/IP reference model and the roles of its layers. You will be able to contrast the TCP/IP model with the OSI model, particularly the layers that are unique to each model. Additionally, consider the advantages and drawbacks of the TCP/IP model. Beyond the layer distinctions, explore other points of comparison between these two models.

    • 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.