{"id":7427,"date":"2022-03-02T13:25:00","date_gmt":"2022-03-02T21:25:00","guid":{"rendered":"https:\/\/cheapsslsecurity.com\/blog\/?p=7427"},"modified":"2022-06-03T13:26:34","modified_gmt":"2022-06-03T21:26:34","slug":"what-is-the-tcp-model-an-exploration-of-tcp-ip-layers","status":"publish","type":"post","link":"https:\/\/cheapsslsecurity.com\/blog\/what-is-the-tcp-model-an-exploration-of-tcp-ip-layers\/","title":{"rendered":"What Is the TCP Model? An Exploration of TCP\/IP Layers"},"content":{"rendered":"\n

Have you ever wondered how you can troubleshoot a network problem? Or how an email you send from Florida is delivered to Tokyo in a matter of seconds? The magic behind it is the TCP\/IP model. Discover everything you need to know about the backbone of the internet and communication transfer. Get ready to network!<\/p>\n\n\n\n

Network protocols like TCP aren\u2019t only relevant to IT networking professionals; they\u2019re everywhere in the digital world and are the foundation of modern communication. Without them, there would be no internet and we would all be back to the 1970s analog world. This means no more online games, streaming, Facebook, video calls, and chats with your family and friends \u2014 practically a dystopian nightmare for many.<\/p>\n\n\n\n

But with these great experiences and opportunities come big risks: TCP-based DDOS<\/a><\/a><\/a> attacks<\/a>, the growing number of detected new attack vectors<\/a>, and a litany of other common network issues. This is the reason why understanding what\u2019s going on behind the scenes of a network protocol can help users and IT specialists alike be prepared.<\/p>\n\n\n\n

So far, you\u2019ve learned the basics of the UDP protocol<\/a> and how UDP works<\/a>. Now it’s time to have a look at TCP, another widely used network protocol. We\u2019ll explore the TCP\/IP model, discover its different components, and learn how it relates to OSI (yes, we\u2019ll tell you more about that too).<\/p>\n\n\n\n

TCP\/IP: What Is the TCP IP Model?<\/h2>\n\n\n\n

Computers and the internet have completely transformed the way we communicate. But just like humans, to be able to interact and exchange information successfully, computers need a common way to communicate. Most of the time, they do that through the transmission control protocol and the internet protocol model (TCP\/IP). TCP\/IP is basically a set of globally standardized rules that enable devices to communicate across networks. No matter which brand they are, where they’re located, and what operating system or software they use, TCP\/IP works, always.<\/p>\n\n\n\n

Have you ever tried buying something in a physical shop, in a foreign country, without speaking the language? I did, and let me tell you, it was an interesting experience. As my knowledge of Japanese was limited to \u201csushi,\u201d \u201carigato\u201d and \u201csumo,\u201d I tried hand gestures, but it only caused puzzled looks.<\/p>\n\n\n\n

To cut the story short, the magic happened when the shop assistant found a colleague who could speak a bit of English (the only one available that day apparently). That day, I not only got a new, shiny, smartwatch, but I also realized how important it is to have a common way to communicate clearly.<\/p>\n\n\n\n

TCP vs. IP: Two Protocols Working Together as One<\/h2>\n\n\n\n

You must have noticed that the two protocols TCP and IP have always been mentioned together. Why? Because even if they\u2019re two separate communication protocols, they work together toward a common goal, operating on different TCP\/IP stack layers. (We\u2019ll speak more about TCP IP layers a little later.) Like the Japanese writer Rynosuke Satoro said, “<\/a>Individually, we are one drop. Together, we are an ocean.\u201d<\/p>\n\n\n\n

TCP is responsible for transporting and delivering the data to the destination application or device defined by the IP. While IP is the part obtaining the address to which the data is sent.<\/p>\n\n\n\n

It\u2019s a bit like when you send a birthday card to your grandmother: the address you write on the envelope is the IP, while the process and the technology that make sure the letter is delivered to the correct address is TCP.<\/p>\n\n\n\n

Whether you send an email, browse the internet, or watch your favorite movies, the TCP\/IP model makes all of it possible. How? It all starts with a handshake \u2014 much like how you shake hands when you meet a new colleague at work or greet a person you know in the street.<\/p>\n\n\n\n

TCP and the Three-Way Handshake<\/h2>\n\n\n\n

Before transmitting packets, TCP must ensure that a stable connection has been set up between the sender and the recipient. This is where the three-way handshake (or SYN-SYN-ACK) comes in. Much like how you\u2019d traditionally shake hands when meeting a new colleague at work or greeting someone you know on the street, there needs to be a similar exchange of messages and acknowledgments that takes place between the two parties in a TCP connection.<\/p>\n\n\n\n

The TCP three-way handshake works as follows:<\/p>\n\n\n\n

  1. The client sends a SYN packet to the server asking him to open a connection.<\/li>
  2. The server responds by sending a SYN-ACK, acknowledging receipt of the SYN packet, and confirming that it’s ready to connect.<\/li>
  3. The client responds with ACK to validate the connection and the transmission of packets starts.<\/li><\/ol>\n\n\n\n

    Easy \u2014 like shooting fish in a barrel!<\/p>\n\n\n\n

    \"A
    A basic overview of the TCP three-way handshake process<\/em>.<\/figcaption><\/figure>\n\n\n\n

    With the handshake done and dusted, we can now go deeper and explore the architecture behind the TCP\/IP model (i.e., the TCP\/IP model layers).<\/p>\n\n\n\n

    Breaking Down the TCP\/IP Model<\/h2>\n\n\n\n

    After completing your last big project, you want to take a few days off from work. You open your mail account, write your request to your boss, click on send and keep your fingers crossed for a positive reply. And abracadabra! Your message is suddenly transmitting from your email account to your bosses where, hopefully, they\u2019ll quickly approve it.<\/p>\n\n\n\n

    But what happens between the time you hit \u201csend\u201d and when it arrives in his inbox?<\/p>\n\n\n\n