Network Models and Protocols
Course Objectives
This text addresses the following broad course objectives. Part II covers the basic terminology and concepts associated with key network models and protocols.
PART I
Introduction | Chapters 1-2
1. Summarize historical and current trends in telecommunications and networking.
PART II
Network Models and Protocols | Chapters 3-9
2. Explain the layers of basic network communications using the OSI and Internet Models.
3. Identify typical network architectures, media access control methods, and distributed routing algorithms used in data transmissions.
4. Discuss network management issues such as reliability, efficiency, and security.
Network Traffic Flow | Chapters 5-6
5. Demonstrate principles of network addressing, subnetting, and routing given sample network scenarios.
Network Traffic Analysis | Chapters 7-9
6. Practice simple network traffic analysis using Wireshark and other tools using protocols such as TCP/IP, SMTP, HTTP, etc.
PART III
Network Infrastructures | Chapters 10-12
7. Describe local and global network topologies and important considerations in their efficiency and reliability.
PART IV
Wireless Technologies | Chapter 13-15
8. Describe emerging trends and technologies in short-range and long-range wireless technologies.
In the world of networking, where data transfer and transmission take place, two foundational models serve as our guides: the TCP/IP model (five layers) and the OSI model (seven layers). These models serve as architectural blueprints, shaping the way data navigates through the complex maze of local and global networks. We will examine the inner workings of connectivity through these lenses.
Behind the scenes, these models illustrate how each layer contributes to data transmission and the end user view and experience. We can look at these layers top-down (application to physical) or bottom-up (physical to application). Let’s look at the layers bottom-up through the OSI seven-layer model. We will explain each of these layers in further detail in the chapters of this part.
Imagine you’re sending an email with an attachment to a colleague across the world. As you hit ‘send,’ your email message is transformed into electrical signals or radio waves, ready to travel across cables or airwaves. Moving up to the Data Link layer, your email packets are equipped with physical addresses, known as MAC addresses. These addresses help guide the packets through switches and bridges within your local network. Once organized, the packets ascend to the Network layer. Here, devices called routers utilize IP MAC addresses to direct the packets across the global network, enabling your email to cross geographical boundaries. Now, your email enters the Transport layer. Here, the message is divided into manageable packets, ensuring efficient transmission.
The final three layers are often grouped together, and prepare the data for the user. The Session layer manages the dialogue control, guaranteeing that the packets are transmitted cohesively, maintaining the integrity of the email conversation. As the data ascends further to the Presentation layer, any necessary encryption or compression is applied. This layer ensures that your email’s content remains secure and can be properly understood by both sender and receiver. Finally, the journey culminates at the topmost layer, the Application layer. Here, your email client, armed with protocols like SMTP and IMAP, initiates the sending process.
This journey reveals how a simple email is sent through the orchestration of layered protocols, through several technical processes. In this section, as we explore the mechanisms behind these communication layers, you will undoubtedly gain a new appreciation for the meticulous underpinnings that enables the digital connectivity we often take for granted.
