The OSI Model

CompTIA Network + Domain:

Domain 1.0: Networking Concepts

CompTIA Network + Objective:

Objective 1.1: Explain devices, applications, protocols, and services at their appropriate OSI layers.

Overview

This lab will utilize Wireshark to review network traffic. Wireshark is a network protocol analyzer licensed under GNU General Public License. A network protocol analyzer is used to capture data packets on a network. Students will review several layers of the OSI model during this lab. Students will be able to describe the encapsulation process and the function of specific protocols that operate within particular layers of the OSI model.

outcomes:

In this lab you will learn to:

  1. Explain the application, presentation, and session layers.
  2. Explain the transport layer.
  3. Explain the network layer.
  4. Explain the data link layer.
  5. Explain the physical layer.
Courses

Key terms and descriptions

Connection-oriented data transfer
a transfer of data that requires the establishment of a connection between communicating endpoints, before the transfer can begin
Connectionless data transfer
a transfer of data that is serviced without requiring a verified session and without guaranteeing delivery of data
De-encapsulation
the process of each layer of the OSI model removing the control information headers on incoming information for the corresponding layer at the destination
Encapsulation
the process of each layer of the OSI model adding control information headers to outgoing network data
IANA
Internet Assigned Numbers Authority; a government-funded group responsible for managing IP address allocation and the Domain Name System (DNS)
IEEE
Institute of Electrical and Electronics Engineers; one of the leading standards-making organizations in the world
IP
Internet Protocol; a core protocol of the TCP/IP suite that resides at the Network layer of the OSI model and provides information about how packets should be routed between networks
MAC address
Media Access Control; the physical address burned into the ROM of an Ethernet network card; used by switches at the Data Link layer of the OSI model to move information between nodes on the same network
OSI
Open System Interconnect; developed by the International Standards Organization (ISO)
OUI
Organizationally Unique Identifier; the first 24 bits (or 3 bytes) of a MAC address assigned by IEEE that identifies the network card’s manufacturer
PDU
Protocol Data Unit; a term used to describe the product of encapsulation at a given layer of the OSI model
TCP
Transmission Control Protocol; the connection-oriented protocol of the TCP/IP suite that resides at the Transport layer of the OSI model
UDP
User Datagram Protocol; the connectionless protocol of the TCP/IP suite that resides at the Transport layer of the OSI model
Wireshark
a network protocol analyzer. It lets you capture and interactively browse the traffic running on a computer network. It has a rich and powerful feature set and is world's most popular tool of its kind. It runs on most computing platforms including Windows, OS X, Linux, and UNIX. Network professionals, security experts, developers, and educators around the world use it regularly. It is freely available as open source, and is released under the GNU General Public License version 2.” Reference: http://www.wireshark.org