Relationship between VPN and VPDN

The full name of VPN is "Virtual Private Network ). As the name implies, a virtual private network is a virtual private line within an enterprise, it can establish a temporary and secure private communication line between two or more intranets located in different places on the Internet through special encrypted communication protocols. A Virtual Private Network is an extension of the enterprise intranet. It can help remote users, branches, business partners and suppliers establish trusted and secure connections with the enterprise intranet, and ensure secure data transmission.

There are two access methods for dividing a VPN by access method: leased line access mode and dial-up access mode.

A VPN (commonly known as a VPN) is a VPN solution provided for users who have connected to an ISP edge router through a leased line. This is a "always-Online" VPN, which can save the cost of traditional long-distance leased lines.

A dial-up VPN (VPDN) is a VPN service provided to users who use the dial-up PSTN or ISDN to access the ISP. This is a "On-Demand connection" VPN, which can save users' long-distance phone fees.

Therefore, VPDN is a form of VPN, but different from common VPN, VPDN is built on the basis of the telephone network. The networking mode is similar to ADSL. Users establish VPDN connections through dialing, is a "On-Demand connection", while a common VPN is a "always online connection"

VPN and VPDN are applicable to different application environments. VPN is suitable for establishing a virtual connection to the network, just like a connection from the network to the network between different branches of the headquarters. The network mode is to use a relatively high-end VPN device as the firewall of the company's internal network at the company headquarters, and use its own VPN gateway function to provide VPN access. For each branch, the VPN access device is used as the firewall and regional VPN node of the company. The VPN device connects to the Internet through ADSL or LAN to achieve communication between the headquarters and branches, and ensure the security and integrity of data communication.

VPDN is suitable for establishing virtual connections to the network of a terminal. For example, an employee can connect to the Intranet of the company through VPDN to access intranet resources. VPDN users access branches through the ordinary telephone network PSTN or ADSL Broadband Network, and use VPDN dedicated accounts to dial into the dedicated authentication server for authentication, after the security authentication is passed, you can access the VPDN server to obtain the enterprise network address and obtain the permission to access the internal network of the enterprise. User data can be transmitted between Intranet and external users through a secure tunnel, which enables secure, fast, and private network access and applications.