Around the world, about a billion people useservices and information resources that offer global computer information networks. More than 150 million computers connected to the Internet store a huge amount of information. The creation of the Internet has led to the need for the formation of a single information space, without which no working organization currently does.
The Internet unites networks:
The first level of the structure of the global connection -local, on which there are networks of buildings, offices, where several dozen computers are combined to provide access to information. Such networks can not provide access to data from users in different parts of the city. Regional networks are the second level of this global structure. They provide remote access to information and unite computers located within the same region, region or country. The global computer network is a complex structure, which includes corporate networks owned by many organizations interested in protecting information. They can include up to several tens of thousands of computers located in different cities and countries.
In the structure of any corporate and local networkthere is at least one Internet server that has a permanent connection to the World Wide Web using a high-speed data link. For such "trunk" lines, always use fiber, which has a bandwidth of 20 Gbit / s and above. A global computer network is the reliability provided by high-bandwidth transmission channels that connect local, regional and corporate segments. For example, the North American regional computer network (US) is connected by multiple data channels from Russian (RU), Japanese (JP) and European (EU).
A global computer network is an associationset of technologies. Fiber-optic communication lines are used to connect local networks to the global one. If they are far away and the cable routing is difficult or impossible, then wireless types of connections are used. If the antenna receiving and transmitting are within line of sight, data transmission can be performed over radio channels, otherwise a satellite channel is used for information exchange. Users connect to the Internet with the help of providers who provide dial-up telephone channels for use. Modems are used to connect the user's computer to the provider's server. These devices transmit data in digital form at a speed of 56 Kbps. Users of portable devices can connect to the Internet using Wi-Fi. A global computer network is a combination not only of networks of different types and purposes, but also of technologies.
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