Figure 4: Option 1- One-Site Installation (DC) with Single 3G
After 3G successfully dial up, at MP1800, one default route will be pointed to interface 3G, and 2 IPSec VPN tunnel will be build: IPSec Tunnel 1 to MP2900-1 (Main) IPSec Tunnel 2 to MP2900-2 (Backup) At MP2900-1 and MP2900-2, we shall apply static route point to each server, and next hop will be to firewall for the incoming traffic from WAN. As for outgoing traffic from LAN, at firewall shall apply control mechanism, for example IPSLA to track the link to MP2900-1 and MP2900-2 respectively for route selection.