# The OSI layers

> Every piece of data that leaves a sensor and reaches a system goes through several communication steps. The OSI model organizes those steps into seven layers, from the bit on the wire to the application the user opens, and it is the map the rest of this module uses.

Source: https://ubivis.ai/en-us/academy/intro-to-industry-4-0/osi-layers/

Introduction to Industry 4.0 · Module 03: communication protocols · Lesson

Every piece of data that leaves a sensor and reaches a system goes through several communication steps. The OSI model organizes those steps into seven layers, from the bit on the wire to the application the user opens, and it is the map the rest of this module uses.

## In this lesson

- Physical, data link and network: the bit on the medium, the MAC address and IP routing
- Transport and session: TCP, UDP, and how a connection is opened, kept and closed
- Presentation and application: encryption, compression, and protocols such as HTTP, SMTP and FTP

## Material for this lesson

[**Module 03 workbook: communication protocols** PDF in Portuguese, made to read and print.](https://ubivis.ai/assets/apostilas/introducao-industria-4-0-modulo-03.pdf) [**See the full course** 3 modules · 14 lessons](https://ubivis.ai/en-us/academy/intro-to-industry-4-0/)

[Business case: Ub-IoT across 20 plants with SENAI](https://ubivis.ai/en-us/academy/intro-to-industry-4-0/business-case-senai/) [Communication protocols](https://ubivis.ai/en-us/academy/intro-to-industry-4-0/communication-protocols/)

## Lessons

[Introduction: why going digital changes the bottom line 6 min](https://ubivis.ai/en-us/academy/intro-to-industry-4-0/introduction/) [What Industry 4.0 is 6 min](https://ubivis.ai/en-us/academy/intro-to-industry-4-0/what-is-industry-4-0/) [The Ubivis story, with the CEO 9 min](https://ubivis.ai/en-us/academy/intro-to-industry-4-0/the-ubivis-story/) [The industry of the future 8 min](https://ubivis.ai/en-us/academy/intro-to-industry-4-0/the-industry-of-the-future/) [How to reach the fourth industrial revolution 7 min](https://ubivis.ai/en-us/academy/intro-to-industry-4-0/reaching-the-fourth-revolution/)

[How to digitize a process: sensors or actuators? 9 min](https://ubivis.ai/en-us/academy/intro-to-industry-4-0/how-to-digitize-a-process/) [What is the difference between digital and analog signals? 8 min](https://ubivis.ai/en-us/academy/intro-to-industry-4-0/digital-and-analog-signals/) [The Internet of Things 7 min](https://ubivis.ai/en-us/academy/intro-to-industry-4-0/internet-of-things/) [IIoT vs. IoT 6 min](https://ubivis.ai/en-us/academy/intro-to-industry-4-0/iiot-and-iot/) [Business case: Ub-IoT across 20 plants with SENAI 5 min](https://ubivis.ai/en-us/academy/intro-to-industry-4-0/business-case-senai/)

[The OSI layers 7 min](https://ubivis.ai/en-us/academy/intro-to-industry-4-0/osi-layers/) [Communication protocols 6 min](https://ubivis.ai/en-us/academy/intro-to-industry-4-0/communication-protocols/) [Protocols on the shop floor 8 min](https://ubivis.ai/en-us/academy/intro-to-industry-4-0/protocols-on-the-shop-floor/) [Business case: communication hurdles on the shop floor 7 min](https://ubivis.ai/en-us/academy/intro-to-industry-4-0/business-case-connectivity/)