In communications between computers, there is what is known as computer networks. These are those that allow each of the processes within a network to be executed in an orderly fashion, making it possible to exchange information between computer systems.
The world of network protocols is truly interesting, since learning from it means getting your hands dirty with the most essential concepts of digital communication on a technical level of course.
In this article we are going to teach you the most important things about network protocols, so that you can use them to study for your high school exam, or simply to broaden your knowledge about them. So pay attention and keep this entry in your favorites.
What is a network protocol and what does it do in a computer system?
A network protocol is a set of rules established in a computer system that dictates the guidelines that must be met, to achieve effective communication between the nodes that make up that system. It is in a way like the rules of transit of the information that flows in the form of bites from one computer to another.
This is very important, because without them, the information transmitted would not be verified, which would mean that nothing could guarantee that it would arrive without errors. Then, it becomes something like a means of communication; full of speculative information and of dubious providence. But most importantly, the commands it contains would be misapplied, causing the applications that execute them to collapse completely.
What are the main network protocols that exist in computing?
In the same computer network there are a tremendous amount of protocols, naming them all would lead us here much more than an article. But the most important and well-known will be named for you next:
Possibly the best known. This is an unreliable data transport protocol. What it does is send data packets (datagrams) from one point of origin to another point of destination, limiting itself to this and not guaranteeing that the packets will be delivered.
This very elementary concept is the basis of Internet communications. It establishes an address to your computer (IP address) and gives it the ability to send data (upload) and receive it (download). There are two known versions of this protocol, IPv4 and IPv6 and the main difference between one and the other is the number of addresses you can assign.
Less well known but very important. It works in conjunction with Internet Protocol version 4, and is responsible for assigning IPv4 addresses to the corresponding equipment. It’s a simple task, but one that makes things much easier. Its initials stand for Address Resolution Protocol.
However, one of its weaknesses is that it does not check that the addresses it assigns are correct, which leaves room for errors.
This protocol has exactly the same function as the previous one, but in this case it is in charge of assigning IPv6 addresses. In this way, it allows a computer to be integrated into the local network, being a link for the datagrams to reach it.
This is another protocol that works in conjunction with the Internet Protocol. It is known as Internet Message Control Protocol, and it is responsible for sending notifications and error messages, reporting scenarios such as the host being impossible to locate or a service no longer being available at the time of your request.
This protocol is mounted on the IP, which often makes both known as TCP/IP. This has exactly the same function, since it is in charge of transporting data from one point to another, with the difference that in each data it adds a checksum or checksum to guarantee the reliability of the transmitted data.
The initials stand for Transmission Control Protocol.
This is a very similar protocol to the previous one, but it deals with the transmission of data in local networks of the same user, without depending on the Internet connection. Like IP, it does not guarantee that data will be received, but this in turn speeds up communications on the network.
What is the OSI classification? What are all the layers that make up this communications protocol?
In the world of network protocols, there is a reference model known as the OSI classification, which is a standard created by the World Organization for Standardization (ISO) in the 1980s, which determines a basic scheme on which the different protocols that exist must be governed. This is not the only one that exists, IBM also created its own System Network Architectura (SNA), but the OSI is still the most popular.
This model consists of 7 layers with different functions that allow communication in a network to be 100% effective. The user only interacts with 2 of them: the first and the last one respectively, since the others occur at the system level.
Here we present each one of them:
Layer 1 (Physical level)
The physical layer is the one that is worth the redundancy, it is composed with all the physical elements of the network, from the machines or computers, to the cables and routers. It also encompasses the concept of network topology, which is nothing more than the way a network is structured to facilitate communications within it.
This is the layer with which the user interacts the most, and it is even said to be the only one since the seventh layer, the application layer, is not executed by the user but by software that the user uses in this first physical layer.
Layer 2 (Link Level)
Known as the data link layer. It works between the physical components and the network (layer 3). It is responsible for processing, verifying and confirming the data issued at level 1 of the OSI model, and then sending it to level 3, which is where the process of sending and receiving information between computers really begins.
This layer is essential, since it is a filter to ensure that the data entering the network is correct, as the protocols of the network layer, in most cases can not do because it would detract from the fluidity of the transport of them.
Layer 3 (Network level)
This layer is where most of the protocols mentioned above coexist. It is in charge of getting the data from a source to its destination, no matter if both points where they are directly connected or if there is an “intermediary” device between them.
The most important element of this is the Internet Protocol (IP) which we explained in the previous point, and it works in conjunction with hundreds of other protocols.
Layer 4 (Transport level)
It is often confused with the previous one, as it has almost the same function when transporting data from one IP address to another within a network with or without an Internet connection. It uses the TCP (online) and UDP (offline) protocols, which work over the Internet or IP protocol. What this does is make the data independent of the network layer, to make its transmission from source to destination much faster.
Layer 5 (Session Level)
Each time an exchange of information between computers is initiated, what is known as a “session” is opened. This level is responsible for keeping the session open while the data exchange takes place, otherwise the exchange could not be completed and communication on the network would be completely impossible.
It is also capable of resuming a session in the event of an unexpected interruption, resuming it from the exact point where it was interrupted.
Layer 6 (Presentation Level)
This is one of the most important layers. All data or datagrams that travel in a network are simple binary numbers, impossible for a normal person to understand. What is done at this level is that these data are interpreted and rewritten so that applications and users can understand them.
Basically, it’s the one that allows you to see an image that you download while you’re surfing the Internet, even though for the web it was a bunch of zeros and ones. In essence, it’s a data translator.
Layer 7 (Application level)
Finally, there is the application level, which allows programs to use the information generated on the network for subsequent execution.
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