Chapter 10 IPsec VPN : IPsec VPN concepts : VPN tunnels
  
VPN tunnels
The data path between a user’s computer and a private network through a VPN is referred to as a tunnel. Like a physical tunnel, the data path is accessible only at both ends. In the telecommuting scenario, the tunnel runs between the FortiClient application on the user’s PC, or a FortiGate unit or other network device and the FortiGate unit on the office private network.
Encapsulation makes this possible. IPsec packets pass from one end of the tunnel to the other and contain data packets that are exchanged between the local user and the remote private network. Encryption of the data packets ensures that any third-party who intercepts the IPsec packets can not access the data.
Figure 174: Encoded data going through a VPN tunnel
You can create a VPN tunnel between:
• A PC equipped with the FortiClient application and a FortiGate unit
• Two FortiGate units
• Third-party VPN software and a FortiGate unit
For more information on third-party VPN software, refer to the Fortinet Knowledge Base for more information.