User Manual - Configuration Guide (Volume 3)

Chapter 1

Versatile Routing Platform

VPN Overview

5)With VPN, users can make mobile access at any time and place, meeting the increasing mobile service requirements.

6)VPN with service quality guarantee, e.g. MPLS VPN, can provide different levels of service quality guarantees for users in exchange for different service charges, harvesting surplus profit. In addition, in terms of implementing the same functions, the networks can be used more effectively when these services are provided by specialized public networks rather than the networks established by the enterprises themselves.

Take an enterprise for example. The Intranet established with VPN is shown in the following figure.

Remote users

PSTN / ISDN

PC

POP

Internet

POP

 

 

POP

 

Headquarter

 

 

 

Partner

 

 

Internal server

 

 

 

Figure VPN-1-1Schematic diagram of VPN networking

It can be found in the above figure that the users of internal resources of enterprises access the POP (Point of Presence) server of local ISP via PSTN network, and thus they can communicate with each other. Conventional WAN construction technique can only score the same goal with the aid of leased line between them. After VPN is established, the remote users and the clients in other places can access internal resources of enterprises even if they do not have the Internet access authority of local ISP. This means a lot to clerks who travel a lot and geographically widely distributed clients.

VPN services of enterprises only require a server supporting VPN at resource sharing location (a Windows NT server or a router supporting VPN). After accessing local POP server via PSTN, resource users directly call the remoter servers of enterprises (VPN servers). The call mode is the same as that with PSTN connection, with the rest of work completed by Access Server of ISP.

1.2 Classification of IP VPN

IP VPN means the simulation of leased line services of private WAN equipment performed with IP facilities (including public Internet or private IP backbone network).

IP VPN has the following classification methods:

I. According to operation mode

1)CPE-based VPN

The users not only install expensive equipment and private authentication tools, but also are engaged in multifarious VPN maintenance (e.g. channel maintenance and bandwidth management). The networking is complicated, but its service scalability is weak.

2)Network-based VPNNBIP-VPN

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Huawei v200r001 user manual Classification of IP VPN, According to operation mode