what is TCP/IP and OSI? // FREE CCNA // EP 3

Summary

This script from a free CCNA course episode highlights the evolution of networking, from the 1960s ARPANET to the development of the TCP/IP and OSI models. It explains how these models standardized communication between devices from different manufacturers, allowing them to 'speak' the same language. The video emphasizes the importance of understanding both models for networking professionals, especially the OSI model's layers, which are still referenced today despite TCP/IP's dominance.

Takeaways

• 📚 The video is the third episode of a free CCNA course sponsored by Boson Software, which provides CCNA and CCNP labs and practice exams.
• 🤖 The Raspberry Pi device mentioned can connect to a network and interact with an iPhone, highlighting the common yet remarkable interoperability of devices from different manufacturers.
• 🕰️ The script takes a historical perspective, starting from the 1960s when the concept of networking computers was first considered, leading to the creation of ARPANET by the Department of Defense.
• 💡 The invention of packet switching was a pivotal moment in networking history, allowing data to be sent across networks, although the specifics of how different devices would communicate were not yet established.
• 🏭 In the early days of networking, companies like IBM created proprietary networks that could only work with their own equipment, leading to a lack of interoperability between different networks.
• 🔄 The realization that a standardized approach to networking was necessary led to the development of networking models that would allow different devices to communicate effectively.
• 🌐 Two main networking models are discussed: the TCP/IP model, which is widely used and implemented in computer systems, and the OSI model, which was a contender but is less commonly used in practice.
• 🔄 The TCP/IP model is a set of rules and guidelines for computer communication, divided into layers that define protocols and standards at each stage of the networking process.
• 🔄 The OSI model is similar to the TCP/IP model but includes two additional layers: the session layer and the presentation layer, which were not adopted in the TCP/IP model but are still referenced in networking terminology.
• 📚 Both models are important for understanding and studying networking, especially for those preparing for the CCNA certification, as they provide a framework for understanding how data moves through a network.
• 🧠 Memorizing the OSI model's seven layers can be facilitated by using mnemonic devices, which are helpful for networking professionals when troubleshooting or discussing network functions.

Q & A

What is the main purpose of the OSI model and the TCP/IP model in networking?

The OSI model and the TCP/IP model serve as frameworks for understanding and designing communication networks. They define layers of networking functions and protocols that enable different devices, even from different manufacturers, to communicate with each other.

Why was the ARPANET created?

ARPANET was created in 1969 by the US Department of Defense as the first network to enable computers to communicate with each other, which was a revolutionary idea at the time and laid the foundation for modern networking.

What is packet switching and why was it significant in the development of computer networks?

Packet switching is a method of grouping data into packets and sending them over a network. It was significant because it allowed for efficient data transmission and was the basis for the development of modern internet protocols.

Why did companies initially create proprietary networks?

Companies initially created proprietary networks because they wanted to control the technology and ensure compatibility with their own products. However, this led to issues with interoperability between different networks.

What is the difference between the OSI model and the TCP/IP model in terms of layer structure?

The OSI model has seven layers, including session and presentation layers, which are not explicitly present in the TCP/IP model. The TCP/IP model is typically described with four layers, combining some of the OSI model's functions into broader categories.

What is the role of the physical layer in the OSI model?

The physical layer in the OSI model is responsible for the actual transmission of data over a physical medium, such as electrical signals over Ethernet cables.

Which device primarily operates at the data link layer (Layer 2) of the OSI model?

A switch primarily operates at the data link layer, managing data flow between devices on the same network using MAC addresses.

What are the two devices that operate primarily at the physical layer of the OSI model, according to the script?

Repeaters and hubs are the two devices that operate primarily at the physical layer, as they deal with the transmission of raw electrical signals without any processing or addressing.

What is the significance of the session layer in the OSI model?

The session layer in the OSI model manages the communication sessions between applications, ensuring that data is exchanged in an orderly and controlled manner.

How does the script describe the evolution of networking from proprietary systems to standardized models?

The script describes the evolution as a shift from proprietary systems, where each company had its own incompatible network design, to standardized models like TCP/IP and OSI, which allowed for interoperability and communication between devices from different manufacturers.

What mnemonic device does the script suggest for memorizing the OSI model's seven layers?

The script suggests the mnemonic device 'All People Seem To Need Data Processing' for memorizing the OSI model's seven layers in order from the application layer to the physical layer.

What is the main focus of the video series mentioned in the script?

The main focus of the video series is to provide a free CCNA (Cisco Certified Network Associate) course, covering fundamental networking concepts and technologies.