Suggestions on specific VPN route technology solutions

With the development of China's routing technology, VPN routing technology is also widely used, which is a very important part of the routing technology. Here we mainly analyze the VPN routing technical solution, hope to help you. Today, Virtual Private Network (VPN) is widely used in the Internet, which allows enterprise networks to expand almost infinitely to every corner of the Earth, thus, the safe and low-cost Network Interconnection model provides a stage for the development of all-encompassing application services.

Virtual Private Network (VPN) is a service that uses public network resources to form a private network for customers. The VPN routing technology we mentioned here has two meanings: it is a virtual network, that is, there is no fixed physical connection, and the network is established only when users need it; it is a private network composed of public network facilities. VPN routing technology is actually a service. users feel like they are directly connected to their personal networks, but they are actually connected through service providers. VPN routing technology can bring the following benefits to enterprises and service providers:

Companies that adopt remote access have paid in advance all the fees for purchasing and supporting the entire enterprise remote access infrastructure;
Companies can use the ubiquitous Internet to provide staff and business partners with secure and secure connections through a single network structure;
For enterprises, the exists based on the dial-up VPN can enhance contact with users, business partners and suppliers;
Telephone companies can use the dial-up VPN service to reduce terminal congestion;
By providing secure external remote access services for the company, ISP can increase revenue. through exclusive layering and Related Competition services, ISP can also provide different dial-up VPNs.

VPN routing technology combines many features of the public network and the private network. It combines the reliable performance and rich functions of the public network with the flexibility and efficiency of the private network, it is a network between a public network and a private network. VPN can make full use of existing network resources and provide economic and flexible connection methods, saving customers the investment required for equipment, personnel and management, and reducing users' Telecom fees, it has been quickly applied in recent years. Some experts believe that VPN will be one of the fastest growing businesses by the end of this century.

What is VPN

Through packets and encrypted transmission of Network data, Private data is transmitted on the public Network to achieve the security level of the Private Network, so as to build an internal Al Private Network (VPN) through the public Network ). If the access method is dial-up, it is called VPDN. VPN routing technology establishes private data transmission channels through public IP networks, and connects remote branch offices, business partners, and mobile office staff. This reduces the cost of remote access, reduces telephone fees, and provides secure end-to-end data communication. VPN can be established in three ways: one is self-built by the enterprise and transparent to the ISP; the other is ISP construction and transparent to the enterprise; and the third is the joint construction of the ISP and the Enterprise.

How VPN works

The similarities and differences between conventional direct dial-up connections and virtual private network connections are that in the previous case, PPP Point-to-Point Protocol) data packet streams are transmitted through dedicated lines. In VPN routing technology, a PPP packet flow is sent from a router on a LAN and transmitted through a tunnel on the shared IP network before arriving at the router on another LAN. The key difference between the two is that the tunnel replaces the real dedicated line. A tunnel pulls a serial communication cable from the WAN cloud. So how to form a VPN tunnel?

There are two main ways to establish a tunnel: the Client-Initiated or the Client-Transparent ). The customer requires both the customer and the tunnel server or gateway to install the tunnel software. The latter is usually installed on the company's central site. The customer software initializes the tunnel, and the tunnel server terminates the tunnel. The ISP does not have to support the tunnel. Customers and tunnel servers only need to establish tunnels and use user IDs and passwords or digital license authentication. Once the tunnel is established, communication can be performed, just as if the ISP is not involved in the connection.

On the other hand, if you want the tunnel to be transparent to the customer, the ISP's POPs must have the access server that allows the tunnel and the router that may be needed. The customer first calls a dial-up to enter the server. The server must be able to identify the connection and establish a tunnel with a specific remote point. Then, the server establishes a tunnel with the tunnel server. Generally, the user ID and password are used for authentication. In this way, the client establishes a direct conversation with the tunnel server through the tunnel. Although this policy does not require the customer to have specialized software, the customer can only dial to access the correctly configured access server.

Key technologies involved in VPN

VPN is a virtual network. Its important significance lies in "virtual" and "dedicated ". In order to transmit private data over the public network, the security of private data must be met. VPN routing technology is mainly reflected in two technical points: Tunnel, related tunneling protocols including PPTP, L2F, L2TP), data security protocol IPSEC ). The following describes these technologies. Encryption and user authorization provide security assurance for personal communication on the company's Internet.