What are the four layers that make up TCP/IP?

Chances are that in your day-to-day life, you use the Internet to do all kinds of tasks or enjoy your leisure time, but it isn’t likely that you’ve ever stopped to think about how it works.

Yes, basically, all we need is a computer and an internet network to connect to and that's it.

But, at the level of internal processes, is it all that simple?

As you can imagine, the answer is no. 

In a simple Google search or when we want to watch a movie on Netflix, our devices develop communication with the internet network that is quite complex.

This is when the TCP/IP protocol comes into use and when it becomes important that its four layers work well.

It’s likely that you have no idea what we’re talking about, don't worry, we won't judge you, but if you want to be informed or if this kind of topic catches your attention, you are lucky that we are going to explain it to you: 

What is TCP/IP?

To get into the subject, you need to know what TCP/IP is so that you have a basic definition of the subject and so that you can understand each of its layers.

Its acronym comes from the full name of Transmission Control Protocol/Internet Protocol.

In other words, it’s a set of network protocols that makes it possible to link the data from the Internet to the devices that use it.

Thanks to this protocol, it’s possible for devices with Internet access to communicate between different networks and thus make web browsing possible.

Therefore, without TCP/IP we would not be able to use the Internet in the way we do today and that’s why it’s used in technological devices such as computers, mobiles...

The four layers of TCP/IP

Now that the concept of TCP/IP is clear, it’s time to talk about the topic that brings us together here today: the four layers of TCP/IP.

This is undoubtedly one of the most outstanding features of this Internet protocol model and it’s what’s made it so effective to use and chosen by a large majority of people.

For this protocol to work properly, the data to be transferred must pass through a total of four layers.

This makes the sending of information (something that happens constantly when we use the Internet), more efficient and it can be received by users much faster.

So, in order for you to understand the importance of each of these layers, we will talk about each of them below:

1. Link or access layer

The first layer of them all is the data link layer and here’s where all the physical parts that are part of the information transfer and connection to the network are located.

That is to say, the wireless network, the Ethernet cable, the controller, the network interface card... 

Therefore, at this first layer, the information transfer reaches those components of the devices that make Internet access possible.

That’s why this level is also known as the access layer, physical layer, or network interface layer, but you should keep in mind that regardless of the name used, we’re talking about the same thing.  

2. Internet layer

Now, when the information is already in the Internet layer, it means that we’re already at the stage in which the sending becomes a tangible reality.

This is the level that is in charge of handling traffic routing and controlling the flow of traffic, which is why some people also refer to it as the internet layer.

In case there’s a lot of traffic, it may take a little longer for the sending and receiving of data to be completed, but it will be this layer that will make sure that everything arrives safely.

Therefore, it’s the internet layer that is responsible for ensuring that the files sent do not arrive damaged.

3. Transport layer

Then it will be time to meet the so-called transport layer.

As its name indicates, it’s the one that functions as the information sending route, since it will provide the reliable connection that the devices need to send information to each other.

This is the layer that is responsible for dividing the information into several packets so that communication is effective and everything is received properly.

At the same time, it will be responsible for confirming that both parties involved have handled the data transfer properly and that the recipient has received the information.

4. Application layer

Last but not least we have the application layer, which is the one with which we usually have the most direct contact on a day-to-day basis.

This is the level at which the information reaches the programs in which we can read it.

Therefore, within this level are all those applications through which the user in question can access the network and the information found there.

Within this layer, we would then find email, cloud storage programs, and all those messaging applications that we use on a daily basis (WhatsApp, Telegram, Facebook... ).

Why is the TCP/IP protocol shaped this way?

Now, you’re probably wondering why this protocol has to be made up of four layers.

As you may have already discovered, each of these layers has a specific purpose and each of them is important for the overall transmission of information.

The point is that TCP/IP works with data and divides it into packets to make the transmission of information much simpler and, above all, faster.

Therefore, all these packets must pass through each of these layers in order and make the process of sending information standardized.

The procedure is that the data passes through these layers in one direction and then the other way around when it reaches its destination.

That is to say, on one computer or server the information passes from layer one to layer four, but when it reaches the next computer it passes from layer four to layer one.

If this process did not work in this standardized way, it’s quite likely that web communication will be much slower and inefficient.

So yes, surfing as fast as we do today is possible thanks to the existence of this protocol.

Are there other network protocols that work through layers?

If you’re aware of the variety of programs and digital tools available today, you will know that there are many types of systems that pursue the same goal.

So, after being aware of the network protocols, it’s normal that you have doubts about whether there are some others besides TCP/IP.

The truth is that there are, but if there is one that is the most closely related to it due to its internal functioning through layers, it’s the OSI protocol or model.

In this case, we’re dealing with a protocol whose acronym stands for Open Systems Interconnection.

This is a protocol that was created ten years after TCP/IP, in 1980, and although it gained popularity and many still use it today, it has not managed to dethrone TCP/IP from its place as the most widely used worldwide.

However, it should be noted that there is a key difference between the two and it has to do with the number of layers. While TCP/IP works with four layers, OSI works with seven layers:

1. Physical.

2. Data link.

3. Network.

4. Transport.

5. Session.

6. Presentation.

7. Application.

Is TCP/IP made up of more protocols?

The answer to this is a clear yes because being related to the Internet and the sending of information through the network, it has a series of internal protocols that make everything that has to do with the transfer of data to be done more effective.

That is to say, thanks to the existence of TCP/IP, we also have other types of protocols that are essential for actions such as accessing specific websites, transferring all types of files, and solving problems with addresses, among others.

Therefore, at a technical level, it’s equally important to know these other protocols that are involved in TCP/IP and with which we usually have contact, although we do not realize it:

• HTTP (Hypertext Transfer Protocol).

• HTTPS (Hypertext Transfer Protocol Secure).

• FTP (File Transfer Protocol).

• DNS (Domain Name System).

• DHCP (Dynamic Host Configuration Protocol).

• Telnet (Bidirectional Serial Text Communication).

• ARP (Address Resolution Protocol).

• SMTP (Simple Mail Transfer Protocol).

• SNTP (Simple Network Time Protocol).

• SNMP (Simple Network Management Protocol).

• TFTP (Trivial File Transfer Protocol).

Do I need to know my TCP/IP address?

On a day-to-day basis, you will probably be able to navigate without the need to know the TCP/IP address of your network and this is something that happens to all of us.

However, it is true that there will be certain procedures or configurations that you want to do to your devices, for which you may need to know what your TCP/IP address is, and that's when you will be left looking around puzzled.

But don't worry, finding out this information is easier than you think.

Although it’s true that there are different ways to find out this information, the simplest of all is to use your web browser.

Access it and perform a search with the question "What is my IP address?", and you will see that several web pages will appear that will give you this information quickly and easily, an ideal option for those who are novices in the use of computers or mobile devices.

At first glance, the whole issue of internal internet protocols, networks, and devices may sound complex and quite technical, but the heart of how they are developed is based on human communication itself.

You will now have figured this out on your own, after having read about how the four layers of TCP/IP work, and thanks to this basic knowledge you will be able to delve deeper into the subject if you wish.

If you are interested in this type of content and want to continue learning, we invite you to take a look at our blog. 

And also leave us your comments in the box below.