Module Title: dgt_net02 – The Application Layer
Overview:
The “dgt_net02 – The Application Layer” module covers the uppermost layer of the OSI and TCP/IP models, focusing on the network protocols, services, and applications that enable end-user interactions. This module is intended for students who have a foundational understanding of networking concepts and want to look more closely at how data exchange happens at the application level.
Once you know what an HTTP request, a DNS resolution or an SMTP session really looks like, you can let the machine do the typing. In the practical sessions you ask the AI agent in natural language to stand up a web server with TLS, to trace a name resolution from the root servers down, or to find out why an email bounces; then you read the headers, records and logs it shows you and decide whether its explanation holds up.
Module Objectives:
– To understand the role and functions of the Application Layer in networking models.
– To explore key protocols used at the Application Layer, including HTTP, FTP, SMTP, DNS, and more.
– To analyze the interaction between the different layers of the OSI model, focusing on applications that rely on this layer for communication.
– To learn to specify, review, and troubleshoot application-level network services that the machine sets up on your natural-language instructions.
Module Content:
- Introduction to the Application Layer
- Overview of the OSI Model and TCP/IP Stack
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Functions and responsibilities of the Application Layer
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Key Protocols and Services
- HyperText Transfer Protocol (HTTP) and HTTPS
- File Transfer Protocol (FTP) and its variants (SFTP, FTPS)
- Simple Mail Transfer Protocol (SMTP) for email communication
- Domain Name System (DNS) architecture and operations
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Network Time Protocol (NTP) for clock synchronization
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Application Layer Security
- Understanding vulnerabilities at the Application Layer
- Introduction to encryption and authentication mechanisms
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Case studies on common application-layer attacks (e.g., DDoS, phishing)
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Developing Application-Level Services
- Basics of APIs and RESTful services: describing an API to the machine and reviewing the implementation it produces
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Design principles for scalable and secure applications
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Advanced Topics in the Application Layer
- Web technologies: WebSockets, AJAX, and real-time data streaming
- Cloud-based application architectures
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IoT and application layer considerations
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Troubleshooting and Optimization
- Tools and techniques for monitoring application-layer traffic, and how to read the captures the machine collects
- Best practices for optimizing performance and reliability
Learning Outcomes:
– Understand the Application Layer’s role in network architecture.
– Be able to direct the configuration and troubleshooting of key application layer protocols in natural language, and to verify the results.
– Strengthen problem-solving skills related to security and efficiency at the application level.
– Prepare for advanced studies or professional roles focusing on application development and networking.
Prerequisites:
A basic understanding of computer networks up to the Transport Layer is recommended. Familiarity with programming concepts is helpful for reading the code the machine produces, but not mandatory.
Assessment Methods:
– Quizzes and assignments to reinforce theoretical knowledge.
– Natural-language labs in which you instruct the machine to configure application layer protocols, then check and troubleshoot what it built.
– A final project in which you guide the machine to design a simple networked application, or to optimize an existing one, and justify every choice it made.
The module “dgt_net02 – Application Layer” covers networking at the level where humans and computers communicate.
The students can push their exercises to the Academy DevOps & SRE Git project. For this module, create a folder with your username as its name in the following subfolder: https://github.com/Garanti-Del-Talento/gdt_academy