H3C Technologies H3C Intelligent Management Center - Manual (Page 16)

Basic VPN concepts
Typically, enterprises must find ways to communicate both internally and externally using increasingly
complex, and potentially insecure, Internet and LAN technologies. One solution is to use dedicated
private lines, which can be expensive, and cannot accommodate mobile offices. A more attractive
solution is using a VPN. Using a VPN allows private networks to run on public networks while providing
the secure and reliable communication of a private network. VPN uses specific tunneling protocols to
transmit VPN packets over different tunnels.
Carriers can make full use of the available network resources to increase services by providing VPN
services to enterprises. And enterprises can select different service levels as needed, therefore getting the
services they need and reducing their networking cost at the same time. Additionally, the scalability of
VPN provides support and convenience for your mobile offices. VPN allows enterprises to connect with
remote offices, staff traveling on business, and business partners at a low cost while improving utility of
network resources.
VPNs can be classified by:
• Networking model
{
VPDN—Point-to-point VPN.
{
Leased line VPN (VPRN, VPLS, VLL).
• Service application
{
Access VPN—Allows users and small offices to establish private network connections with the
intranet or extranet of their enterprise over a public network.
{
Intranet VPN—Interconnects points distributed inside an enterprise.
{
Extranet VPN—Extends an enterprise network to co-operators by using VPN.
• Operation mode
{
CPE-based VPN CPN—IPsec, VPN, GRE VPN, and VPDN.
{
Network-based CPN—Includes CLL, CPRN, CPLS and L3VPN, conducted by ISP. All functions
are implemented at network device side.
• Working layer
{
L2VPN
{
L3VPN
Quick guide
This chapter provides a quick guide that helps you use MPLS VPN Management to add and maintain
VPNs.
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