Monthly Archives: July 2021

NETWORK LEVEL In telecommunications and information technology in the context of computer networks, the network layer is level 3 of the ISO / OSI stack. This layer receives segments from the above transport layer and forms packets which are passed to the underlying data link layer. The task of the network layer is the logical transmission of packets between two arbitrary hosts, which in general are not directly connected (that is, they do not have a direct connection between them), i.e. essentially it deals with addressing and routing to the right destination through the most appropriate network path. NETWORK [...]

TRANSPORT LEVEL The transport layer, in telecommunications, information technology and in the field of computer networks, is the fourth of the layers in the ISO/OSI model. Its task is to provide services to the above level Application of the TCP/IP model and to achieve this it uses the services offered by the underlying level 3 (network level). The purpose of the transport layer is to provide an end-to-end logical communication channel for packets, essentially providing logical communication between application processes of different hosts. FUNCTIONALITY The following are the services that are generally offered by the transport [...]

In telecommunications, the application layer is the seventh and last layer of the ISO / OSI model for computer networks. Its function is to interface and provide services for application processes; in transmission, therefore, it forwards the requests to the underlying presentation level, while in reception it receives them. An application program interacts with one of the transport layer protocols to receive data or send it by passing it in the required form. Among the most common services offered by the application layer are semantic conversions between associated application processes. DYNAMIC HOST CONFIGURATION PROTOCOL In telecommunications and IT, the [...]

HOSTNAME AND IP ADDRESSES If I want to visit Google I will not write in the browser 216.58.205.78 but simply google.com. This can happen because a binding has been made between the Google IP and the name google.com. LOCAL TRANSLATION You can enter IP associations: Name manually in the hosts.txt (Windows) and /etc/hosts (Linux and MacOS) files: THE DNS In computer science and telecommunications, the Domain Name System  is a system used to assign names to network nodes (in English: hosts). These names can be used, by means of a translation, usually called "resolution", in place [...]

THE SMTP PROTOCOL If email is email, SMTP is the postman. Without the standard network protocol of the modern Internet it would not have been possible to send application documents, videos, mp3s etc. This is because when you send an email, it doesn't go directly to the recipient, but instead goes through a complex process of communicating with numerous instances before arriving at its destination. The SMTP server is a mail server that sends e-mails from a sender to one or more recipients on the Internet and forwards them over the network according to the rules of the SMTP [...]

FTP PROTOCOL In the Internet, as well as in other networks, communication between people and devices takes place by means of protocols. It is as if they established the rules of communication: who should send certain information and when? What happens if the data does not reach the recipient? How is transmission protected from disturbances and interference? Therefore, whenever we surf the Internet, protocols of the ISO/OSI model are used. The best known are HTTP and HTTPS, which are the protocols we usually use to call up websites. Another important protocol is FTP. But what is it used for? [...]

THE HTTP PROTOCOL “HTTP” stands for “Hypertext Transfer Protocol” and was developed by Tim Berners-Lee at CERN (Switzerland) along with other concepts that formed the foundation for the World Wide Web: HTML and URI. While HTML (Hypertext Markup Language) defines the structure of a website, HTTP regulates the way in which this page is transferred from the server to the client. The third concept, URL (Uniform Resource Locator), defines how the resource (such as a website) should be addressed on the web. By "Hypertext", the term that appears in the abbreviations HTTP and HTML, we mean a concept we [...]