VPN (Virtual Private Network) is a generic name for technologies that allow one or more network connections to be made over another network (for example, the Internet). In spite of the fact that communications are carried out on public networks using unsafe protocols, encryption creates closed information exchange channels from outsiders.
The VPN online allows to combine, for example, several offices of an organization into a single network using uncontrolled channels for communication between them.
What is VPN used for?
VPN allows you to connect a remote user to the corporate network. The user can stay at home, on vacation or on a business trip and at the same time use corporate services without problems.
In addition, companies can protect the transfer of data within the company with the VPN. On all devices used by employees, mandatory use of VPN connections is compulsory wherever. Even the use of the Internet in this case goes through the corporate network and under the supervision of the security services.
VPN makes it possible to connect not only individual users to the corporate network, but entire offices or buildings of one organization into a single network, rather than stretching the cable each time. No less often, VPN networks are used between servers or entire computing clusters to maintain their availability and duplication of data.
A few words about the Internet traffic
The VPN connection is also considered a reliable node when connected to any public networks, it protects traffic from possible interference by intruders. In private, VPN allows you to bypass a variety of network restrictions. For example, to gain access to resources that are blocked or do not provide their services in a particular territory.
In addition to the usual VPN networks, there are VPN servers. The difference between them is that such devices often change the communication channels used, this can be a 3G / 4G network, and then Wi-Fi.
Technical aspects of VPN
The very principle of VPN operation does not contradict the basic network technologies and protocols. For example, when a remote access connection is established, the client sends a packet of standard PPP protocol packets to the server. In the case of the organization of virtual lines between local networks is leased, their routers also exchange PPP packets.
However, a fundamentally new point is the forwarding of packets through a secure tunnel, organized within a public network. Tunneling allows you to send packets of the same protocol in a logical environment that uses a different protocol. As a result, it becomes possible to solve the problems of interaction of several different types of networks, starting with the need to ensure the integrity and confidentiality of the transmitted data and ending with the overcoming of inconsistencies in external protocols or addressing schemes.