Understanding the OSI Model

A conceptual framework that divides network architecture into 7 layers, enabling communication between devices in a logical progression. Lower layers handle data transmission, while higher layers manage applications and user interactions.

Primary use as a teaching tool for understanding network functions, protocols, and troubleshooting.

The lowest layer in the OSI model responsible for the physical transmission of data bits over communication media between devices.

The process of moving binary data from a sender to a receiver across a network.

A set of design principles and standards used to organize components and build network systems.

Identifying and fixing network problems efficiently by understanding functions within each layer.

Standards for communication between devices, defined at different levels of the OSI model and used for various processes. Examples include IP and ARP.

Improves understanding of network functions, improves troubleshooting, and enhances communication with other technical personnel.

Lowest layer, transmits data as signals (electricity, light, radio waves).

Checks for errors, packages bits into frames, manages MAC addresses, controls access.

Determines data destination, handles routing, uses IP addresses and ARP.

Delivers data across connections, error recovery, flow control, possible re-transmission.

Manages network connections, supports dynamic connection creation.

Unit of data transmitted at the Data Link Layer

Unique logical address for devices on a network.

Unique physical address for a network device, used for local communication

Syntax processing, including format conversion and encryption/decryption, supporting the Application layer.

Provides network services to end-user applications, typically working with user data through protocols.

An application enabling a user to interact with a Web server.

Protocols like HTTP that manage data packaging for communication between layers.

The Presentation layer provides data to, and receives data from, the Application layer.

The act of selecting a server and asking for web page content via an address or link.

Provides files that combine to form a web page.

The top layer of the OSI model, responsible for application services.

Allows computers to find web servers on the internet.

Finds the physical address (MAC) of a device, given its IP address.

The device a computer uses to connect to the internet.

A request to a web server for a web page from a web browser.

Inserts the web request into a network request to the default gateway.

Converts data formats for display; handles image, sound, and text display.

Web browsers open TCP connections (sessions) to servers for web pages, and to load additional files within the page. Each file request is a new session.

Breaks down Web pages into chunks, labels them, and moves them across the correct session.

IP layer, figures out where a webserver is (local or internet), using unique addresses.

A computer initiates a TCP connection with a web server and requests a web page.

Manages network connections; controls how a web browser and server communicate and how to find additional files.

Handles reliable transport of data between web browsers and web servers.

Web browsers, using instructions in HTML, automatically fetch extra resources (styles, images, etc.,) from a server.