Computer networks: basic concepts, characteristics, history

The history of computer networks originates from the moment a person understands the need to combine computing and other capabilities of several computers for working together on large information arrays, as well as storing, processing and transmitting large amounts of data. The characteristics of computer networks can carry a variety of information, but perhaps the most important components that include computer networks, the basic concepts for the construction of which will be discussed below, are the products of the Internet exchange.

Dealing with such a complex issue as computer networks, basic concepts are simply necessary to know. Without this knowledge, the network will never function as it should, and this entails huge losses of time and money of the enterprise.

So, computer networks basic concepts - the means of internetworking. It is worth noting that the market for these devices is one of the fastest growing. The main purpose of the means of internetworking is to ensure the interconnection between users, united in a huge, and often distributed over a large area of ​​a local network.

Computer networking basic concepts include six types of interconnecting products.

Repeaters

A repeater is a hardware device that operates at the physical level of the OSI model and provides the ability to connect together a pair of segments of one computer network.

Hubs

The main purpose of the hubs is to perform the task of mounting nodes that provide the connection of each autonomous network device and segment. There are several types of hubs represented by passive, active, and intelligent.

Bridges

This term refers to means that are designed to transmit data packets between two networks. Bridges make it possible for programs and protocols to consider interconnected networks as a whole. In addition to data transfer, bridges can filter them.

Routers

Using routers, a logical connection is required for individual networks. At the same time, the united networks use the same protocol. It is understood that routers are protocol-dependent devices that must be endowed with the ability to support certain routing protocols. It is the presence of routers on the network that makes it possible to have multiple packet transmission paths. In addition, the router is an β€œintelligent” device that can determine the optimal path for each packet from a wide list of possible routes.

Gateways

The most common definition of the term "gateway" refers this concept to any hardware or software package designed to combine a pair of heterogeneous systems. In this sense, a gateway can be considered a communication server or an access server.

The fact that the operation of the gateways is "multi-level" distinguishes them among routers, bridges and repeaters that can operate at only one hierarchical level (this can be a network, data link or physical layer, respectively). In addition, routers, bridges, and repeaters are not able to perform data conversion.

Switches

A switch is a device whose main purpose is to redirect input to one of the outputs. For example, data packets arrive at the input of the switch, and its output is connected to the Ethernet bus. In this embodiment, the device will be called an Ethernet switch

The switch must have the means of organizing the necessary connections, as well as tools to convert the input information into the correct output format.

Source: https://habr.com/ru/post/C30335/


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