The linking of two or more computers is referred to as a computer network. It’s done to make it possible for computers to interact and share resources.
Computer Networks Types
The following are some of the most common forms of computer networks.
The Local Area Network (LAN)
A local area network (LAN) is a kind of network that is meant for small physical locations like an office, a collection of buildings, or a factory. LANs are frequently utilised because they are simple to construct and troubleshoot. Local area networks (LANs) link personal PCs and workstations. Through LAN, we may employ a variety of topologies, such as Star, Ring, Bus, Tree, and so on. A local area network (LAN) may be as basic as connecting two computers to exchange data and network with one another, or as complicated as integrating a whole building. LANs are also often used to share resources like printers, shared hard drives, and other such items.
Network of Metropolitan Areas
A metropolitan area network (MAN) is essentially a larger version of a local area network (LAN). It is based on the same technology as a LAN. It serves as an ISP and covers a vast geographical region (Internet service provider). Customers that need high-speed connection will benefit from a MAN. MAN has a modest data transmission rate and propagation latency. Modems and wire/cable are the devices used to transmit data through MAN. A MAN is a component of a telephone company’s network that may offer a high-speed DSL connection to a client or a city’s cable TV network.
Wide Area Networking (WAN)
A wide area network (WAN) is a computer network that spans a vast geographic region, albeit it may be limited to the boundaries of a single state or nation. A WAN is a network of local area networks (LANs) that link to other LANs through telephone lines and radio waves. It may be restricted to a single firm (a corporation or organisation) or open to the public. The technology is both high-speed and low-cost. WAN devices include optic lines, microwaves, and satellites for data transport. Switched WAN and point-to-point WAN are the two forms of WAN. The asynchronous transfer mode (ATM) network is an example of a switched WAN, whereas a dial-up connection connecting a home computer to the Internet is an example of a point-to-point WAN.
LAN (Local Area Network)
A personal area network (PAN) is the smallest sort of network, consisting of a wireless modem, one or more computers, phones, printers, tablets, and other devices, and centred on one person in a single building. These networks are often found in tiny workplaces or homes, and they are controlled by a single person or organisation using a single device.
VPS (Virtual Private System)
A virtual private network (VPN) is a network security technology that establishes a secure and encrypted connection across a public network such as the Internet. VPN technology was created to provide secure access to business applications and other resources to distant users and branch offices. Data flows over secure tunnels to provide security, and VPN users must acquire access to the VPN using authentication mechanisms such as passwords, tokens, and other unique identifying techniques.
A server is a network device that is shared by several users.
A file server is a computer on a network that provides access to files to other network users.
Internet Connection Types
The following are some of the most common forms of Internet connections.
Dial-up Internet Connection
Dial-up technology connects to the Internet by using an existing phone line to establish a semi-permanent connection. It monopolises the phone line and is the slowest means of accessing the Internet since it operates on a single channel. It is often the only kind of Internet connection accessible in rural regions, since it needs no infrastructure to connect to the Internet other than the already existing telephone network. Dial-up connections often do not surpass 56 kbit/s since they are typically established using a 56k modem.
Broadband Internet Access
The phrase “broadband connection” refers to a variety of technologies that all enable high-speed Internet access. It maintains a continuous connection without requiring a dial-up or in process, and it does not “hog” phone lines. Because of its fast connection speeds, it is the most popular mode of Internet access. The following are the many types of broadband connections available:
DSL (digital subscriber line)
This leverages an existing two-wire copper telephone line linked to the premise to offer service concurrently with wired telephone service; unlike an analogue dial-up connection, it does not hold up your phone line. ADSL and SDSL are the two primary types of DSL available to residential users. xDSL is the umbrella term for all forms of DSL technology. The speed of an xDSL connection varies from 128 Kbps to 9 Mbps.
This uses the cable television infrastructure to transfer data over the radio. A cable modem is used to connect to the local cable TV provider. A coaxial cable or a hybrid fibre coaxial cable is used to carry data. The cable network offers speeds ranging from 512 Kbps to 20 Mbps.
Fiber optics: Fiber optic cables are used to transport data completely or partly.
The tiny glass wires within the bigger protective cable are referred to as “fibre.”
The term “optic” relates to the way light signals are transmitted. Fiber connections may provide 1 Gbps data transfer rates to households and businesses.
Broadband over power line (BPL)
This technology allows for high-speed Internet and home network connectivity via standard electrical lines and power connections in the house. It was developed as a replacement for conventional wired broadband Internet technologies like DSL and cable modems. Some individuals use the terms BPL (broadband over power line) to refer to home networking and IPL (internet over power line) to refer to long-distance Internet access.
Radio frequency bands are utilised instead of telephone or cable networks in a wireless Internet connection. This is a “always-on” Internet connection that may be accessed from any place within the network’s service area. The usage of a modem, which picks up Internet signals and delivers them to other devices, enables wireless connections. The following are some examples of wireless Internet connections:
Wi-Fi (wireless fidelity)
Wi-Fi is a wireless high-speed Internet and network connection that employs radio waves. Wireless (or Wi-Fi) hotspots are basically wireless access points that provide network and/or Internet connectivity to mobile devices like your laptop or smartphone, usually in public places like shopping malls, restaurants, hotels, airports, train stations, parks, and so on.
WiMAX stands for Worldwide Interoperability for Microwave Access. This is a standardised wireless version of Ethernet designed to give broadband connectivity to client premises as an alternative to wire technologies (such as cable modems and DSL). It would work similarly to Wi-Fi, but at better rates and for a larger number of users across longer distances.
Mobile broadband is another name for mobile wireless broadband service. It’s also known as WWAN (wireless wide area network), and it’s a common word for high-speed Internet connectivity for mobile devices from mobile carriers. Using built-in mobile broadband network cards or other portable network devices, such as USB modems or portable Wi-Fi mobile hotspots, mobile broadband services may also give wireless Internet access on your laptop or netbook.
Internet over satellite (IoS) is a technology that enables users to connect to the Internet through a satellite orbiting the earth. A satellite is set in situ at a fixed altitude above the earth’s surface. When compared to cable and DSL, the immense distance that a signal travels from the earth to the satellite and back results in a delayed connection.
An intranet is a private network run by a major corporation or other organisation that employs Internet technology but is not connected to the rest of the world.
An extranet is an intranet that is open to visitors from outside the corporation or is shared by many organisations.
Services that are integrated ISDN (Integrated Services Digital Network) is a telecommunications technology that allows digital data to be sent over ordinary phone lines. It may be used to make phone calls as well as send and receive data. It has a data transmission rate of 64 kilobits per second.
Architecture of the Network
Peer-to-peer and client/server architectures are the two most common types of network architecture.
Peer-to-Peer Network (P2P) is a kind of peer-to-peer
A peer-to-peer (P2P) network is another name for a peer-to-peer (P2P) network. Each workstation has the same powers and duties in this scenario. This is in contrast to the client/server design, which dedicates certain workstations to servicing the others. Peer-to-peer networks are often easier to set up and less costly, but they don’t always operate as well under large loads.
Network of Clients and Servers
Each machine or process on the network is either a client or a server in a client/server architecture. Servers are high-performance computers or processors that manage disc drives (file servers), printers (print servers), or network traffic (network servers). Users execute apps on clients, which are less powerful PC desktops. Clients depend on servers for file storage, device management, and even computing power.
The OSI Model There are a large number of users who connect to a computer network from all over the globe. As a result, the International Organization for Standardization (ISO) has produced a standard to guarantee that national and international data communication systems are interoperable with one another. This is known as the OSI model, and it is a model for Open System Interconnection (OSI).
The architecture of this model is seven layers thick. In a comprehensive communication system, it specifies seven tiers or levels.
Application: The application layer is the one with which users and user applications interact the most. Network communication is considered in terms of resource availability, communication partners, and data synchronisation.
The presentation layer is in charge of mapping resources and establishing context. It converts lower-level networking data into information that applications expect to see.
Session: A connection handler is the session layer. It persistently makes, maintains, and removes connections between nodes.
The transport layer is in charge of providing a secure link to the layers above it. The capacity to verify that a piece of data was received intact at the other end of the connection is referred to as dependable in this context. This layer may resend data that has been lost or damaged, as well as acknowledge data reception from distant systems.
The network layer is responsible for routing data between nodes on the network. It utilises addresses to determine which machine it should transmit data to. Larger communications may also be broken down into smaller bits and reassembled on the other end using this layer.
Data Link: This layer is used to create and maintain reliable connections between nodes or devices in a network by utilising existing physical connections.
The physical layer is in charge of dealing with the actual physical devices that are utilised to establish a connection. This layer includes both the hardware and the minimal software that maintains physical connections (like Ethernet).
Devices for Networking
Network devices link computers and other electronic devices so they may share data and resources. In a computer network, various networking devices serve distinct responsibilities. The following are some of the most common computer networking devices.
A repeater is a device that works at the physical layer. Its role is to regenerate the signal across the same network before it gets too weak or garbled, allowing the signal to be sent over longer distances on the same network. Repeaters do not enhance the signal, which is a crucial aspect to remember. They replicate the signal bit by bit and renew it at the original intensity when it gets faint. It’s a gadget with two ports.
A hub is nothing more than a multiport repeater. The connection in a star topology that links distinct stations is an example of a hub that joins many wires originating from separate branches. Data packets are transmitted to all connected devices since hubs cannot filter data. To put it another way, the collision domain of all hosts linked to a hub stays the same. They also lack the intelligence to choose the optimum routing for data packets, resulting in inefficiencies and waste.
At the data link layer, a bridge is used. A bridge is a repeater with the added capability of filtering material by reading the source and destination MAC addresses. It may also be used to join two LANs that utilise the same protocol. It is a two-port device since it has just one input and output port.
As the name implies, a gateway is a path that connects two networks that may use different networking paradigms. They essentially serve as messengers, taking data from one system, interpreting it, and transferring it to another. Gateways, also known as protocol converters, may function at any layer of the network. A gateway is more complicated than a switch or router.
A switch is a multi-port bridge with a buffer and a design that may improve its efficiency and performance (a high number of ports suggest less traffic). A data link layer device is a switch. A switch that performs error checking before transmitting data is particularly efficient since it does not transfer packets with mistakes and only forwards good packets to the proper port. To put it another way, a switch splits the collision domain of hosts while keeping the broadcast domain the same.
A router, similar to a switch, is a device that directs data packets according to their IP addresses. A router is primarily a device that operates at the network layer. Routers link LANs and WANs and use a dynamically updated routing table to decide how to route data packets. Routers are devices that separate the broadcast domains of hosts connecting to them.
A modulator demodulator is referred to as a modem. That is, it modulates and demodulates the signal between a computer’s digital data and a telephone line’s analogue signal. It transforms a computer’s digital impulses into analogue signals so that they may be sent via phone lines. It may be used to connect to an ISP or as a dial-up for a LAN. It may be external, such as a device that connects to a computer’s USB or serial port, or proprietary devices for portable gadgets and other devices, or internal, such as add-in expansion cards for computers and laptop PC cards.