TCP/IP Model Explained | Cisco CCNA 200-301

Summary

In this video by CertBros, the TCP/IP model, an essential framework for networking, is unpacked and explained. While the OSI model is more commonly referenced in academia, the TCP/IP model is widely used in real-life applications. The video covers its layers, updates, and how they correlate with the OSI model. It explains each layer's role from application protocols to physical networks, focusing on encapsulation and decapsulation processes. This is essential knowledge for those pursuing a Cisco CCNA certification.

Highlights

• The TCP/IP model streamlines networking with its practical use and simple structure, while the OSI model is more theoretical. 📚
• The updated TCP/IP model now includes five layers: application, transport, network, datalink, and physical. 🖥️
• Encapsulation wraps each layer with necessary headers and trailers as data ascends or descends through the layers. 🌀
• The TCP/IP's five layers correspond closely to the OSI model's seven layers, aiding in understanding network protocols. 🔍
• Practical knowledge of the TCP/IP model is crucial for those pursuing Cisco's CCNA certification. 🏆

Key Takeaways

• The TCP/IP model is more commonly used in practice compared to the OSI model. 🌍
• The TCP/IP model consists of five layers: application, transport, network, data link, and physical. 📊
• Encapsulation adds information at each layer when sending data, while decapsulation removes it when receiving. 🔄
• The TCP/IP model aligns closely with the OSI model, making it a handy conceptual tool. 🔗
• CCNA aspirants should focus on understanding TCP/IP as its widely applied in networking roles. 💼

Overview

First off, let's debunk the myth: while many talk about the OSI model, the TCP/IP model is what truly gets used in the real world. It's like the rockstar of the networking world with its straightforward, application-oriented approach. Comprising five layers, it simplifies the networking process significantly by merging some of the layers seen in the OSI model.

Breaking it down, the video details how each layer operates: from the application layer, buoyed by protocols like HTTP and FTP, all the way down to the nitty-gritty physical layer, full of cables and network cards. Each layer does its part in processing and transmitting data by adding its unique header information—a process fondly known as encapsulation.

Finally, remember the reverse journey for data as it’s received, aptly termed decapsulation. By stripping each layer's header, the data eventually reaches its destination. This straightforward model not only makes life easier for network engineers but is a cornerstone concept for Cisco's CCNA program, helping newbies and pros alike understand data communication at its core.

Chapters

• 00:00 - 00:30: Introduction to TCP/IP Model The chapter introduces the TCP/IP model and its importance in networking. The TCP/IP model is discussed in relation to the OSI model, with a recommendation to watch a prior video on the OSI model for better understanding.
• 00:30 - 01:00: Comparison with OSI Model The chapter compares the TCP/IP model with the OSI model, noting that both aim to standardize computer networking. While the OSI model is well-known, it is less commonly used in practice compared to the TCP/IP model, which consists of four layers: application, transport, internet, and link, similar to the OSI’s approach.
• 01:00 - 01:30: Updates in TCP/IP Model The updated TCP/IP model consists of small but significant changes, with an additional layer and a renaming of an existing layer. The link layer has been divided into two separate layers: datalink and physical. Furthermore, the internet layer has been renamed to network layer.
• 01:30 - 02:00: Comparison of Layers This chapter discusses the comparison between the TCP/IP model and the OSI model. It highlights that while the OSI model has seven layers, the TCP/IP model has five. Specifically, it points out that the application, presentation, and session layers in the OSI model are represented as a single application layer in the TCP/IP model. Additionally, it mentions that the other layers correspond closely across both models, reinforcing the reader's existing understanding of these networking frameworks.
• 02:00 - 02:30: Protocols and Devices at Each Layer The chapter focuses on the various protocols and devices that operate at each layer of a network. At the application layer, common protocols include HTTP, FTP, and SMTP. In the transport layer, TCP and UDP are predominant, with port numbers also being a key feature. The network layer features the Internet Protocol (IP) and routers. Finally, the data link layer is mainly about Ethernet switches, though some layer 3 switches can also handle routing tasks.
• 02:30 - 03:00: Physical Layer Overview The chapter provides an overview of the physical layer of networking, which involves tangible components such as cables and network interface cards. It explains the concept of encapsulation, where each layer of the network adds its own information as data is sent. The chapter highlights that at the physical layer, this data is then transmitted to the receiving device, which initiates the process of unpacking the transmitted data.
• 03:00 - 03:30: Data Encapsulation and Transmission The chapter 'Data Encapsulation and Transmission' discusses the process of data encapsulation as depicted in the OSI model, focusing especially on the decapsulation of data in a detailed analysis. Starting at the application layer (Layer 5), data is passed down through the layers where headers are added. For instance, at the transport layer, a TCP header is appended which incorporates details such as source and destination port numbers, sequence numbers, among other critical pieces of information.
• 03:30 - 04:00: Encapsulation Process Detailed The chapter titled 'Encapsulation Process Detailed' delves into the intricacies of the encapsulation process in networking. Firstly, it covers the addition of an IP header at the network layer, which includes the source and destination IP addresses, among other details. Subsequently, the data link layer is explained, emphasizing the addition of both a header and a trailer. The header includes the destination and source MAC addresses, while the trailer incorporates error checking information essential for the receiving end.
• 04:00 - 04:30: Decapsulation Process The chapter titled 'Decapsulation Process' explains the journey of data as it is transmitted through different network layers. Initially, data at the physical layer is checked to ensure it has been received correctly, marking the end of the encapsulation process. The chapter emphasizes the importance of naming conventions at various stages: at layer five, the data is simply referred to as "data"; after adding transport information, it is termed a "segment"; and additional details about the network layer are provided.
• 04:30 - 05:00: Conclusion and Course Information The chapter discusses the process of data encapsulation and decapsulation as it occurs in networking. It describes how data is segmented into packets and further encapsulated into frames with data link information before transmission. Upon reception, a computer checks the destination MAC address to confirm if the frame is intended for it, then processes the IP information to ensure the packet is destined for the correct destination. If all criteria are met, the data is further processed by the receiving system.

TCP/IP Model Explained | Cisco CCNA 200-301 Transcription

• 00:00 - 00:30 Hey whats up guys? Welcome to CertBros In this video, we're going to be talking about the TCP/IP model Quick warning, we're going to be referencing the OSI model a lot here so if you haven't already watched that video check that out first then come back ok so what is the TCP/IP model? It's a model to
• 00:30 - 01:00 standardize computer networking. Sound familiar? It should because it's the same description as the OSI model. Now the OSI model while widely referenced isn't used in the real world the TCP/IP model, however, is the real deal Thankfully is not that different here is the TCP/IP model. Four simple layers, application, transport, internet and link And just like the OSI model, it's numbered from the bottom up, but the direction depends on if you're sending or receiving traffic
• 01:00 - 01:30 So this is the original model but it has been updated Here is the brand new freshly designed model One extra layer and one renamed layer that's it the link layer has been split into datalink and physical and the internet layer has been renamed the network layer
• 01:30 - 02:00 simple right? It gets even better when we compare the TCP/IP model to the OSI model Now if you remember the OSI model has seven layers compared to our five here but when you look at it you'll notice the application presentation and the session layers are just shown as application layer in the tcp/ip model all the other layers line up nicely which is great because we should already know the concept of how this works So let's remind ourselves about the
• 02:00 - 02:30 protocols and devices at each layer. At the application layer we have application protocols such as HTTP FTP and SMTP. The two most common transport protocols are TCP and UDP. Port numbers are also added here. At the network layer we have the Internet Protocol or IP. Routers also operate at this layer. The data link layer contains ethernet Switches typically at this layer, although you can get layer 3 switches that have some routing capabilities
• 02:30 - 03:00 Finally, we have the physical layer. Think of everything we can touch and feel here. Things like cables and network interface cards Ok, so as we send data each layer will add its own bit of information. This process is called encapsulation. When we hit the physical layer the data is transmitted over to the receiving device. The receiving device then starts to
• 03:00 - 03:30 decapsulate the data. We saw this in the OSI model but in this video we're going to take a closer look. We start with our application data at layer 5 this is then passed down to the next layer where the transport information is added. Let's say is a TCP header. Each time a header is added this will contain specific information. For example a TCP header will contain things like the source and destination port number, sequence numbers and a few more bits of information.
• 03:30 - 04:00 We'll go over this in more detail in a separate video. We then move to the network layer where we add the IP header. This will contain the source and destination IP address as well as some other bits of information. Lastly we have the data link layer. Here we add not only a header but a trailer as well. The header contains main lead the destination and source MAC address and the trailer contains some error checking information that the receiving side can
• 04:00 - 04:30 check and make sure the data has been received correctly. Once the data hits the physical layer it is physically transmitted so we've gone through the encapsulation process. It's important to note that at each stage the data has a specific name. At layer five the data is called, well it's just called data at this stage. Once the transport information has been added it's now called a segment. Adding the network layer information makes our
• 04:30 - 05:00 segment a packet and finally once we add our data link information the packet becomes a frame. Now once data has been transmitted the receiving computer decapsulates the information. It will check the destination MAC address for that frame and if the frame is destined for our computer it's processed further the computer then checks the IP information off the packets again if the packet is destined for our computer is processed further.
• 05:00 - 05:30 The transport information is read and the application data is sent to the receiving application. So that's it for the TCP/IP model after looking at the OSI model thankfully there isn't much else to learn. This video is part of our full CCNA course which can be found in the description. If you like this video, don't forget to like, comment and subscribe. The feedback from you guys really does help the channel
• 05:30 - 06:00 thank you for watching