Archivi categoria: networking

The OSI Model

The OSI (Open System Interconnection) model is like a recipe for how computers communicate. It’s divided into 7 layers, each with its own job, from sending data to making sure it’s delivered correctly. Imagine it as a delicious cake with layers, where each layer has a specific role in making the cake perfect. The OSI model helps computers work together, just like the layers of a cake work together to make it tasty and complete.

From bottom to top:

1. Physical Layer (Layer 1): This is like the foundation of a building. It deals with the actual wires, cables, and hardware, and how bits of data are turned into electrical signals for sending over the network.
2. Data Link Layer (Layer 2): Think of this as the structure of a building. It manages how data is organized into frames and sent between devices on the same network, like your home’s Wi-Fi. MAC address is here very important
3. Network Layer (Layer 3): This is like the road system that connects different buildings. It deals with routing data between different networks and uses IP addresses to make sure data gets to the right place. This layer ensure that each segment will reach the correct IP. Thanks to routers (and IP) that choose the best path 😉
4. Transport Layer (Layer 4): Imagine this as the mailroom in a big office building. It ensures that data is sent reliably and in the right order. It also handles error-checking. TCP and UDP will ensure this. Segmentation (data is segmented/splitted into little segments, each segment has the port number to identify the correct application to send to this data, and it has also the sequence number in order to rebuild the data correctly). Flow control to control to amount of data to transfer.
5. Session Layer (Layer 5): Think of this as a friendly conversation between two people. It establishes, maintains, synchronises, and ends connections between devices. In this case between the client and the server: session management, authentication and authorization
6. Presentation Layer (Layer 6): This layer is like a translator. It makes sure that the data sent by one device can be understood by another by handling data encryption/decryption and compression. Basically ASCII data is translated into binary format, and then compressed in order to have faster communication, and then encrypted (https).
7. Application Layer (Layer 7): This is the (network) software you use, like web browsers or email clients, or Skype, or FTP software, … It provides the interface for you to interact with the network. These applications are “network application”, basically all applications that use network.

Each layer has its own specific job, and they work together like a team to ensure data is sent, received, and understood correctly across a network.

A Beginner’s Guide to IT Jargon

In today’s digital world, understanding the basics of IT and networking is crucial. It’s essential to grasp fundamental terms and concepts. This article aims to simplify and explain key networking terms to help you navigate the world of technology effectively.

Host

A host is any device connected to a network, such as a computer, smartphone, or server. It uses unique identifiers like IP addresses to communicate with other devices on the network.

Link

A link is the physical or logical connection between two devices within a network, typically established using cables or wireless connections. It enables data transmission between devices.

Gateway

A gateway is a device that connects different networks, serving as a bridge between them. It directs data traffic between the local network and external networks, like the internet.

Wi-Fi

Wi-Fi is a wireless technology that allows devices to connect to a network without using physical cables. It is widely used for internet access and networking in homes, schools, and businesses.

Endpoint

An endpoint is a device or software application that communicates with a network. Endpoints can be computers, smartphones, or IoT devices, and they are vital for network access and data exchange.

VPN (Virtual Private Network)

A VPN is a secure network connection that encrypts data transmitted between your device and a remote server, ensuring privacy and security. It is often used to protect online communication and access restricted content.

Switch

A switch is a networking device that connects multiple devices within a local network. It efficiently directs data packets to their intended destinations, improving network performance.

UTM (Unified Threat Management)

UTM is a comprehensive security solution that combines multiple security features like firewall, antivirus, intrusion detection, and more into one device or software to protect a network from various threats.

NAT (Network Address Translation)

NAT is a technique used to map multiple private IP addresses to a single public IP address. It helps conserve IPv4 addresses and enables multiple devices to share a single public IP.

DHCP (Dynamic Host Configuration Protocol)

DHCP is a network protocol that assigns IP addresses and network configuration settings dynamically to devices when they connect to a network. It simplifies network administration.

MAC Address

A MAC (Media Access Control) address is a unique identifier assigned to network devices at the hardware level. It is used to distinguish devices on a local network.

TCP/IP (Transmission Control Protocol/Internet Protocol)

TCP/IP is a set of protocols that govern data transmission over the internet and most computer networks. It defines how data is addressed, transmitted, and received across networks.

Protocol

A protocol is a set of rules and standards that govern communication between devices on a network. It ensures data is transmitted consistently and reliably.

IP (Internet Protocol)

IP is a set of rules and addressing conventions that enables data packets to be routed and delivered on the internet. IPv4 and IPv6 are two common IP versions.

Subnet

A subnet is a division of a larger network into smaller, more manageable segments. Subnetting helps optimise network performance and organisation.

Network Class

Network class refers to a classification system for IP addresses based on their range and usage. Classes include A, B, C, D, and E, with each serving a different purpose and accommodating a specific number of devices.

Understanding these essential networking terms is a great first step in mastering the world of IT. As you continue to explore this fascinating field, these definitions will serve as a foundation for your knowledge and skills. Whether you’re setting up a home network, troubleshooting connectivity issues, or pursuing a career in IT, these terms will be invaluable in your journey.