3Com Switch 8800 Family IPsec Module Configuration and Command reference Guide

102 CHAPTER 7: VPN OVERVIEW
Virtual Private Dial Network (VPDN) means implementing virtual private network
by employing the dial-up function of public networks (e.g. ISDN and PSTN) and
access networks, to provide access service for enterprises,, small ISPs, and mobile
businesspersons.
3 VPLS service
Virtual Private LAN Segment (VPLS) interconnects LANs via virtual private network
segments in virtue of IP public networks. It is an extension of LANs on IP public
networks.
4 VPRN
Virtual Private Routing Network (VPRN) interconnects headquarters, branches and
remote offices via network management virtual router in virtue of IP public
networks. There are two kinds of VPRN services: VPRN implemented using
traditional VPN protocol (IPsec, GRE, etc.) and VPRN by means of MPLS.
Classified by working layer
1 L3VPN: including BGP/MPLS VPN, IPsec VPN, GRE VPN, etc.
2 L2VPN: including MPLS L2VPN in Martini mode, MPLS L2VPN in Kompalla mode,
MPLS L2VPN in SVC mode, VPLS and static CCC configuration.
3 VPDN: including L2TP, PPTP, etc.