Billion Electric Company BiPAC 8501/8521 - Manual (Page 135)

Billion BiPAC 8500/8501/8520/8521 SHDSL (VPN) Firewall Bridge/ Router
Chapter 4: Configuration
131
Example: Configuring L2TP LAN-to-LAN VPN Connection
The branch office establishes a L2TP VPN tunnel with the head office to connect two private
networks over the Internet. The routers are installed in the head office and branch office
respectively.
Attention
Both office LAN networks MUST be in different subnet with LAN to LAN
application.Functions of Pre-shared Key, VPN Connection Type and
Security Algorithm MUST BE identically set up at both ends.
Attention