• Unit 3: The Application Layer

    In this unit, we will examine the application layer of the TCP/IP stack. The application layer is where all network processes and applications run. We will explore five of this layer's prominent applications: the Domain Name System (DNS), e-mail protocols, the World Wide Web's Hypertext Transfer Protocol (HTTP), Simple Network Management Protocol (SNMP), and Secure Shell (SSH). Finally, we will discuss socket programming and how it can be used to develop network applications.

    Completing this unit should take you approximately 20 hours.

    • 3.1: Principles

    • 3.2: Application-Level Protocols

      • 3.2.1: Domain Name System (DNS)

      • 3.2.2: Electronic Mail (SMTP and POP3)

      • 3.2.3: HyperText Transfer Protocol (HTTP)

      • 3.2.4: Simple Network Management Protocol (SNMP)

      • 3.2.5: The Secure Shell (SSH) Protocol Architecture

    • 3.3: Writing Simple Networked Applications

    • 3.4: Summary

    • 3.5: Practice Exercises

    • Unit 3 Assessment