The private network is a special line connection between two enterprises, which is a physical connection between the internal networks of two enterprises. The special line is a permanent telephone line connection between two points. Unlike the general dial-up connection, the line is always connected. The biggest advantage of this connection is safe. In addition to these two legally connected private networks, anyone else and enterprises cannot enter the network. Therefore, the private network guarantees the security and integrity of the information flow.
The maximum drawback of a private network is too high because the line is very expensive. Everyone who wants a private network needs a separate dedicated (telephone) line to connect them together.
For example, if a company wants to establish an external network connection through a private network and 7 companies, companies must pay 7 special lines. Enterprises generally refer to this issue as "scaling": increasing the number of private networks is very difficult, expensive and time consuming. So how do companies build close and dedicated links between their internal networks? The answer may be an external network designed according to the virtual private network.
Virtual Dedicated Network
Virtual PrivatePrivateNetwork (VPN) refers to the technology of establishing a private network on a public network. It is called a virtual network, mainly because the connection between any two nodes of the entire VPN network does not have the end-to-end physical link required for the traditional private network, but the network provided by the public network service provider. Platform, such as Internet, ATM (Asynchronous Transfer Mode), FrameRelay (Frame Relay), etc., user data is transmitted in logical links. It covers an extension of private networks, encryption, and authentication links across shared networks or public networks. VPN mainly adopts tunnel technology, plus intercourse technology, key management technology and user and equipment identity authentication technology.