What is a Network?

[Virtual Presenter] Today we are going to discuss the two most critical components of a network: physical connection and logical connection. Physical connection means the hardware such as wires, cables, and wireless media that connects two or more computers. Logical connection on the other hand is the data that is transported across the physical media, allowing the two computers to communicate and share resources. Both physical and logical connections form the basic structure of any network..

[Audio] To be able to send and receive data in a network, computers need to utilise communication protocols that are specifically designed for that purpose. These protocols guarantee that data is transferred accurately, avoiding any errors or inefficiencies. Crucial consideration must be given to the source and target of the data, such as IP and Mac Addresses, in order for the data to be sent to the right place..

[Audio] Focusing on the two main aspects of a network – its physical and logical connections – we will begin by examining the various types of networks available, including Personal Area Network (PAN), Local Area Network (LAN), Wireless Local Area Network (WLAN), Campus Area Network (CAN), Metropolitan Area Network (MAN) and Wide Area Network (WAN). Having a better understanding of these networks helps us to understand the physical and logical connections needed for them to operate..

[Audio] A peer-to-peer network consists of each computer on the network being considered a 'peer', with each peer being able to act as client or server. This makes establishing a network easy and is common in homes and small businesses due to the lack of centralized control over shared resources, as any device on the network can freely share its resources. Servers provide resources while clients receive them, and a centralized administrator helps manage user accounts, security, and access control, thus simplifying the network administration..

[Audio] Communication has become more efficient with the advances in technology. Computers and computer networks are now used instead of the postal service to send and receive information. Email, video conferencing, and other forms of communication have become available due to the use of computer networks. They not only allow for faster communication, but also promote the use of standard policies and procedures. In addition, data backup and recovery support is offered and can result in great savings in costs..

[Audio] Ultra-small networks enable data sharing between two or more devices for personal use. Wired or wireless, these networks can involve different combinations of devices, such as smartphones and laptops, smart watches and smartphones, and heart rate monitors and smartphones. This offers an alternative to larger networks to stay connected and exchange data..

[Audio] A network is necessary for both businesses and homes. It is composed of two parts; physical connections such as cables, wires, and wireless transmission, and logical connections that move data through the physical media. A network confined to a specific area, like a room, house, or a cluster of buildings, is classified as self-contained. All of the items in that network are connected either by cables or short-range wireless technology, which does not entail leasing an Internet Service Provider line. Examples of such networks are home networks, and small business or office networks..

[Audio] A local area network (LAN) is a network that relies either on wireless connections or on a traditional wired LAN connected to a wireless LAN (WLAN). This is a popular solution for home networks. By combining these two connection types, the network can communicate with each other in an efficient and effective way..

[Audio] A computer network is composed of two essential components: physical connection and logical connection. Physical connection includes wires, cables, and wireless media, while logical connection is the way data is transmitted between physical media. For instance, a network of several Local Area Networks (LANs) that are interconnected with one another and used or owned by a single entity can be seen in one limited area such as a corporate business park, government organization, or university campus. The combination of both the physical and logical components are necessary for an effective computer network..

[Audio] Computer networks consist of both physical connections, such as cables, wires, and wireless media, and logical connections, which is the data that is securely transmitted over the physical media. This enables users to access computer resources located in one area or across a wide area network, allowing them to collaborate, share information, and work together from any location..

[Audio] Wide Area Networks (WANs) are computer networks that extend beyond multiple cities and countries, generally utilizing leased telecommunications lines from Internet Service Providers. A typical instance of this is a corporate office in distinct locations connected by WAN. Computer networks comprise two primary components: physical connection and logical connection. Physical connection necessitates the use of wires, cables, and wireless media, while logical connection is the process of transmitting data over the physical media. WANs provide a perfect model of this binary, connecting over great expanses of area and interfacing geographically dispersed Local Area Networks..

[Audio] Computers in a network must employ the same communication protocols for transmitting and receiving data, in order to guarantee that the data is correctly delivered and remains functional. These protocols decide the source and destiny of information, such as its IP and Mac address. To make sure that these connections are feasible, the network must comprise both physical connections like wires and cables, as well as logical connections that transfer data through the physical medium..

[Audio] Networks allow computers to be connected and to share resources with one another. They consist of two components: physical connection, which consists of wires, cables and wireless media, and logical connection, which concerns data being transferred across the physical connection..

[Audio] Computadoras interagem uns com os outros usando protocolos de rede. Esses protocolos são regras que estabelecem como as máquinas trocam informações e estabelecem uma comunicação eficaz. Exemplos comuns do dia a dia, como discar um número no telefone ou dirigir um carro de acordo com as leis de trânsito, são aplicações dessas regras..

[Audio] The physical protocols used in computer networks allow us to establish the connection medium and signals necessary for communication. Alongside these physical protocols, logical protocols dictate the software that controls how and when data is sent and received. This means that many different types of protocols are needed in order for a network to function properly. A good example is the TCP/IP suite of protocols, which are responsible for web communication, email, and file transfers..

[Audio] The OSI Reference Model is a concept formulated by the International Organization for Standardization (ISO) in 1977 to illustrate how data is transmitted across a network. By existing as a visual representation of how data travels, it helps us break down complex networking operations into seven distinct layers. Despite not being implemented in today's networks, the OSI Reference Model has been instrumental in the development of the TCP/IP protocol used in most modern networks..

[Audio] The Open System Interconnection Model is a foundational element of network communications. It breaks down the complex task of computer-to-computer networking communications into seven distinct layers. Each layer performs a specific set of functions, such as data formatting, encryption, and connection management. The upper layers are handled by the host computer while the lower layers provide network-specific functions such as routing, addressing, and flow control. Together, these layers form the backbone of a powerful network connections across physical and logical mediums..

The OSI Model Visualized.

OSI Communication.

The TCP/IP Model. The TCP/IP suite is the most commonly used protocol suite in the networking world. It’s essentially the protocol suite in which the Internet was built. It’s the standard for computer networking. It is based on a 4-layer model that is similar to the OSI model. History of TCP/IP: Developed by the United States Department of Defense (DoD) in the early 1970s. In 1982, the DOD declared TCP/IP as the standard for all military computer networking. In 1984, broad adoption of TCP/IP began (IBM, AT&T, etc.)..

TCP/IP & OSI Models Side-by-Side.

[Audio] We are going to investigate the basics of network connections. We will be looking at two main elements: the physical connection (wires, cables, wireless media) and the logical connection (transporting data across the physical media). We will examine the MAC address (Media Access Control address), the physical address of the network adapter card, the OSI Layer 2 Address, the TCP/IP Layer 1 Address, and the six-byte Unique Identifier (Organizational Unique Identifier). We will also discuss how the IEEE assigns the first three bytes (twenty-four bits) while the organization assigns the last three bytes (another twenty-four bits), which guarantees up to sixteen million unique addresses..

[Audio] IP addresses are critical for any IP network, as they act as a unique identifier to route information across the network. This course will explore both the more commonly used IPv4 and the newer IPv6 address version..

[Audio] A network's physical connection consists of cables, wires, and wireless media, and data is transported across these physical media through the logical connection. Network Interface Cards are physically embedded with Media Access Control addresses, enabling networks to communicate through hubs, switches, and routers. Local Area Networks communicate through IP addresses assigned to each operating system, permitting network-to-network communication through routers. WANs, or Wide Area Networks, enable communication over greater distances..

[Audio] Data transmission over a network can occur in either full-duplex or half-duplex mode. In half-duplex mode, data can be transmitted in one direction only; it cannot be sent and received simultaneously. In contrast, full-duplex mode allows for two-way communication, with data being sent and received at the same time..

Network Transmission Types. Unicast Multicast Broadcast.

Unicast (One-to-One).

Multicast (One-to-Many).

Broadcast (One-to-All).

[Audio] A Local Area Network (LAN) is a family of standards which define the physical and logical components required to create a network, such as physical cabling, connectors, network access methods and other equipment. These elements allow for a secure and reliable connection between computers and other devices, making it the most popular networking technology in the world..

[Audio] Network connections involve two main aspects. The physical connection encompasses wires, cables, wireless media and more. The logical connection is how data is transmitted over the physical media. Physical topologies illustrate how network devices are placed and connected physically. In contrast, Logical topologies exemplify how data moves through the network..

[Audio] When examining a network, four key technologies must be taken into account: Bus, Ring, Star, and Mesh. In Bus networks, one node is in control, with the rest taking the role of a slave. Ring networks establish a chain of nodes in a circular formation, Star networks employ a central hub for communication, and Mesh networks employ several nodes for communication and routing purposes..

[Audio] Network connectivity requires physical and logical connections. A single coaxial cable is used, with terminators at each end to prevent signal bounce. Data signals travel in both directions and are received by all devices on the network. One break in the cable can cause the entire network to shut down. Investing in quality components and using advanced technology is thus essential..

[Audio] All devices in a network are connected in a circular fashion. Each computer is connected to two other devices and data can travel from node to node in unidirectional or bidirectional routing. As a repeater, each device in the ring is regenerating the signal. However, if a single node fails, it can bring down the whole network. For redundancy, Fiber Distributed Data Interface (FDDI) uses two counter-rotating ring topologies..

[Audio] Network consists of two main aspects - physical connection and logical connection. Physical connection includes wires, cables, and wireless media, while logical connection refers to the data transfer occurring via the physical media. In order to form a network, all the devices must be connected to a central connecting device, usually a switch, which then forwards the data to the specific destination device. Various popular topologies are generally used in large and small networks. Advantages of topology include reduction of single point of failure of the central device..

[Audio] In a mesh network, each device is connected to every other device through separate cabling. This makes the network extremely redundant and fault-tolerant. Although this type of network requires a large installation cost and is primarily used in large or enterprise networks and wide area networks (WANs), there are two types of mesh networks - partial and full mesh..

[Audio] Technology is revolutionizing education, introducing new tools for learning. Wireless networks are now increasingly being used as they utilize radio frequencies to communicate. Three specific topologies of networks in this regard are Ad-hoc, Infrastructure, and Mesh..

[Audio] Bonjour ! Dans cette diapositive, nous abordons les deux principaux aspects d’un réseau : la connexion physique (câbles, fils, supports sans fil) et la connexion logique (transfert de données a travers les médias physiques). Les réseaux pair à pair et les réseaux sans fil où il n'y a pas de point d'accès sans fil sont des exemples d'infrastructures sans fil. De plus, les réseaux personnels sont un exemple commun de réseaux Ad Hoc sans fil. Ces dispositifs communiquent directement entre eux. Merci..

[Audio] Wireless networks offer the ability to connect in a network space without the need for cables and wires. They offer a useful solution when cables are not possible. Wireless networks that use a Wireless Access Point (WAP) are Infrastructure Wireless Networks (WLANs). WLANs are commonly found in homes and small offices, providing greater flexibility of connection..

[Audio] Wireless Mesh Networks are gaining widespread adoption, due to their robust form of wireless networking. Leveraging multiple access points or 'nodes' creates networks that are both scalable and self-healing, making them a reliable option for both home and business environments. With advancements in technology, we can now enjoy the convenience of wireless data transmission..

[Audio] Your network device's installed network adapter provides physical and electrical connections to the network media, such as an expansion card, USB devices, or those built into the motherboard. This physical connection is crucial for the successful transmission of data across the media, and is one of the fundamental components of a successful network..

[Audio] Les commutateurs sont le principal moyen de transférer des données sur un réseau, remplaçant les équipements hérités plus inefficaces et à l'origine des erreurs de collision de réseau. Les réseaux sont composés de deux aspects principaux: une connexion physique (câbles, fils, supports sans fil) et une connexion logique (transfert de données sur les supports physiques). Les appareils de niveau 1 stupides et les réseaux ne sont plus utilisés à cause de leur inefficacité..

[Audio] Network devices are essential components of modern computer networks, responsible for connecting devices together. They provide both physical and logical connections - the physical connection consists of wires, cables and wireless media, while the logical connection handles the transport of data across the physical medium. Network devices are enabled with Application-Specific Integrated Circuits (ASICs) and Content Addressable Memory (CAM) tables, and use the MAC addresses of connected devices to facilitate data transmission from one port to a single destination port while also breaking up collision domains. These devices are a crucial part of today's networks, delivering high bandwidths and reliability..

[Audio] WAP, short for Wireless Access Point, is a bridge that facilitates connectivity between a wired and wireless network. It operates at the Data Link Layer, similar to a switch, but does not substitute a router. WAPs provide a secure, dependable connection between networks and devices, granting the ability to transport data over physical media..

[Audio] Streaming makes it possible to increase the coverage of a wireless network, functioning as a wireless repeater. It transmits radio waves from the connected wireless network, enlarging the broadcast radius. As a result, we can generate a stronger and larger wireless connection for dependable streaming..

[Audio] Using physical and logical connections, networks can exchange information. IP addresses and routing protocols are used to identify the most efficient way of sending and receiving data. Routers, switches and hubs on Network Layer 3 can separate broadcast domains and provide increased stability. Because of this technology, we can access a vast amount of information regardless of distance..

[Audio] Modems are devices that enable communication between two different systems. They convert signals from one type to another, such as from analog to digital, so that they can be read and processed by routers. To achieve this, modems transform one type of signal into another, allowing for efficient and reliable transmission. This is what allows for networks to be both physically and logically connected..

[Audio] Network concept consists of two core parts - physical and logical connection. To create a connection between multiple devices, we use wires, cables, and wireless media. Data transmission across these physical media establishes the logical connection. All-in-One Wireless Router is a modern innovation that is transforming the way networks are configured. It offers broad capacities like router, wireless access point, firewall, switch, DHCP server, NAT device, file server, and more. This device lets us lower the costs of building and running networks..

[Audio] Et netværk består af to hoveddelkomponenter; fysisk forbindelse (ledninger, kabler, trådløse medier) og logisk forbindelse (data transport over det fysiske medie). Det omformerer en medietype til en anden, som navnet antyder. Det fysiske lag bruger signalomdannelse, og Ethernet til fiberoptisk mediekonvertere er almindelige..

[Audio] Firewalls are a key security measure in a network infrastructure, providing protection against malicious activity from the internet by filtering data packets that pass through them. Firewalls come in both hardware and software versions, allowing for both network-based and host-based protection. These controls form the foundation of a defense-in-depth network, allowing businesses to protect their networks from unwanted traffic and malicious activity. Thank you for your attention..