Lab 2.3.5 OSI Model - Overview

Estimated time: 20 min.

Objectives:

> This Lab will focus on your ability to accomplish the following tasks:

> - Name the seven layers of the OSI model in order using a mnemonic (memory jogger)
> - Describe the characteristic, functions and keywords relating to each layer
> - Describe the packaging units used to encapsulate each layer
> - Name several protocols and standards that operate at each layer

Background:

> This lab will help you develop a better understanding of the seven layers of the OSI model. You will identify the characteristics of each layer as well as the terminology at each layer. The OSI model was developed by the ISO to help provide a common framework for the development of both Local Area Networks (LANs) and Wide Area Networks (WANs). Most network architectures and companies do not adhere exactly to the OSI model but use it to describe their products and compare them to others. The OSI model helps us troubleshoot networking problems by breaking down the networking process (communication from hosts to servers) into distinct layers where functions must occur and identifying tools which can help to isolate the problem. An understanding of the OSI model is essential to success in the world of networking. This lab focuses on the Ethernet network architecture and the Internet Protocol suite (TCP/IP).

Tools / Preparation:

> You may work individually or in teams. The following resources will be required:

> - PC workstation with monitor, keyboard, mouse, and power cords
> - Windows operating system (Win 95, 98, NT or 2000) installed on PC
> - NIC installed and Cat 5 patch cable with connection to the Internet
> - Browser software installed (Netscape Navigator 4.6.1 or higher or Internet Explorer 5.1 or higher
> - Java, JavaScript, and Style Sheets (must be enabled in your browser's preference settings)
> - Flash plug-in (Curriculum version 2.1 only)
> - Apple QuickTime, RealPlayer G2 and ShockWave Macromedia browser plug-ins (Curriculum version 1 and 2 only)

Notes:

Step 1 – The OSI model and associated TCP/IP protocol stack layer.

> Task:

Fill out the following charts based on your knowledge of the OSI model.
Explanation: Your understanding of the OSI model will greatly increase your ability to absorb and categorize networking information as you learn it.

1. List the 7 layers of the OSI model from the top to the bottom. Give a mnemonic word for each layer that can help you remember it and then list the keywords and phrases that describe the characteristics and function of each.

Layer # | Name | Mnemonic | Key Words and Description of Function
7 |  |  |
6 |  |  |
5 |  |  |
4 |  |  |
3 |  |  |
2 |  |  |
1 |  |  |

2. List the 7 layers of the OSI model and the encapsulation unit used to describe the data grouping at each layer.

Layer # | Name | Encapsulation Unit or Logical Grouping | Devices or Components that Operate at this Layer
7 |  |  |
6 |  |  |
5 |  |  |
4 |  |  |
3 |  |  |
2 |  |  |
1 |  |  |