VPN Implementation Unlimited Application

VPN (Virtual private network) means to establish a private data transmission channel through the public IP network, connect the remote branch office, the mobile office personnel and so on, and reduce the cost of the enterprise remote access. VPN has both public and private network features, the public network of reliable performance, rich functions and special network flexible, efficient combination. VPN can save investment for customers, reduce the cost of telecommunications, has been rapidly applied in recent years.

Analysis of traditional VPN technology

From the perspective of operator start-up business, there are three main types of VPN: dial-up VPN (VPDN), Virtual leased line (VLL) and virtual Private routing network (VPRN).

VPDN refers to the use of public network dial-up and access network (such as PSTN, ISDN), the realization of virtual private network for enterprises, small ISP, mobile office staff to provide access services, suitable for the location of decentralized, personnel dispersed, the line of confidentiality and availability of certain requirements of users.

Vll is one of the simplest IP VPN technologies that provides users with point-to-point links to the Data link layer (Layer 2). It is more common to use ATM, FR, and MPLS link encapsulation to provide VLL. There are two links on the link layer at the same time, such as ATM and IP tunnels, and the data is transmitted by relay on both of these links.

VPRN is the simulation of a multicast-specific wide-area routing network, VPRN will use the public IP network to establish a virtual tunnel network among multiple VPN members. This approach differs from VPDN and vll by using VPRN to establish a sophisticated virtual network between multiple VPN members. Compared with the ordinary IP service, the VPN business has the following advantages.

Secure communication can help remote users, company branches to establish a trusted secure connection, and ensure the secure transmission of data.

Low cost by moving the data stream to a Low-cost IP network, an enterprise's virtual private network solution will drastically reduce the cost to users of both the metropolitan and Remote network connections.

The addition and deletion of scalable VPN users is only a logical operation, without the need for specialized physical devices and connections.

Easy to manage the enterprise can outsource the VPN solution to the ISP, and focus on the enterprise's own business, rather than on the network.

The secure access VPN for mobile users can be used for global Internet access of growing mobile users worldwide.

Quality of Service (QoS) guarantees that VPNs can provide a certain quality of service assurance for services that require service quality assurance, such as IP telephony.

Implementation of VPN service

Network interconnection of VPN service

The network interconnection of VPN service can have the following two kinds of structure.

1 interconnection between network and network via VPN

　　

This structure of IP VPN is appropriate for VPN between enterprise branches, between government agencies, or between ISPs.

2 The interconnection between the host and the network via VPN

　　

This structure is appropriate for normal dial-up users or enterprise employees to dial in to VPN via PSTN or ISDN lines.

The technical guarantee of VPN service

The VPN has the following functions to ensure the normal business development.

Transparent packet transfer

The amount of VPN traffic should be independent of the business volume of the IP backbone network, and the resources allocated for VPN should be as far as possible with the resources allocated for the public IP network.

Business Quality Assurance

IP VPN solution should be able to have a certain QoS mechanism, for VPN and VPN with different quality of service requirements of the business to provide different services.

IP VPN solutions should be able to achieve end-to-end application transparency, i.e., the QoS information carried by a business flow should be the same on both ends of the VPN.

Qos

One of the technical requirements for VPN is to provide certain quality of service (QoS) guarantees, such as time delay and jitter. Although a lot of research and experiment have been done in this field at home and abroad, the QoS mechanism is not mature, and the large-scale actual use on the network is not yet. The most effective way to improve QoS today is still to ensure adequate bandwidth.

Comparison of several traditional VPN methods

With the development of IP technology and mobile communication technology, a variety of technologies are emerging to realize VPN service, and to meet the requirements of users ' security, efficiency and flexibility. In the process of enriching and perfecting this kind of technology, more and more enterprise users will know and feel the VPN service based on the public IP network and benefit from it.