IP VPN is to emulate WAN device private line service (such as remote dial-up and DDN.) with IP devices (including public Internet or private IP backbone network).

IP VPN has the following classification method.

Classification According to Operation Mode

Classification according to operation mode is as follows:

• CPE-based VPN (Customer Premises Equipment based VPN)

  Users need to not only install expensive devices and special authentication tools, but also maintain complex VPN, such as channel maintenance, band width management.

  Networking in this way features by:

  • High complexity

  • Low ability of service extension

• NBIP-VPN (Network-based VPN)

  Outsource VPN maintenance to ISP (meanwhile permit users to conduct service management and control to some extent), and realize its functions altogether at network devices.

  In this way, we can:

  • Reduce investment of users.

  • Reinforce the flexibility and scalability of services.

  • Bring new incomes to carriers.

Classification According to Service Application

Classification according to service application is as follows:

• Intranet VPN

  Intranet VPN interconnects each distributed point inside an enterprise by public network. It is an extended or substitute form of traditional private network or other enterprise networks.

• Access VPN

  Access VPN provides private network connection between staff on business, remote businessman, remote mini-office, and Intranet and Extranet of an enterprise through public network.

  Architecture of access VPN is divided into:

  • Client-initiated VPN connection

  • NAS-initiated VPN connection

• Extranet VPN

  Extranet VPN extends enterprise network to suppliers, cooperators, and clients by using VPN, so as to create VPN between different enterprises by public network.

Classification According to Networking Mode

Classification according to networking mode is as follows:

• Virtual Leased Line (VLL)

  VLL is an emulation of traditional leased line service. By emulating leased line through IP network, it provides asymmetric, low cost "DDN" service. From the view of end users of VLL, it is similar to traditional leased line.

• Virtual Private Dial Network (VPDN)

  VPDN realizes VPN by using dial-up of public network (such as ISDN and PSTN) and access network.

  In this way, it provides access service for:

  • Enterprises

  • Mini-ISPs

  • Mobile businessmen

• Virtual Private LAN Segment (VPLS)

  VPLS interconnects LANs through VPN segment in IP public network. It is an extension of LAN in IP public network.

• Virtual Private Routing Network (VPRN)

  VPRN interconnects headquarters, branches, and remote office rooms through network management virtual router in IP public network.

  There are two kinds of VPRN services.

  • One is VPRN realized through traditional VPN protocol (such as IPSec and GRE).

  • The other is VPRN by means of MPLS.

Good to know about it. Thanks.