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Fundamental Principle of VPN
The fundamental principle of VPN indicates to enclose VPN message into tunnel with tunneling
technology and to establish a private data transmission channel utilizing VPN Backbone so as to realize
the transparent message transmission.
Tunneling technology encloses the other protocol message with one protocol. Also, encapsulation
protocol itself can be enclosed or carried by other encapsulation protocols. To the users, tunnel is
logical extension of PSTN/link of ISDN, which is similar to the operation of actual physical link.
3.9.1 IPSec
To build IPSec VPN tunnels, users need to set up IPSec and then add VPN tunnels.
3.9.1.1 IPSec Settings
From navigation panel, select
VPN>>IPSec,
then enter “
IPSec Settings
” page, as shown below.
Page description is shown below:
Parameters
Description
Default
Enable NAT-Traversal
(NATT)
Normally enable NATT; unless
there is no NAT routing
Enable
Keep alive time interval of
NATT
Set alive time interval
60 seconds
Enable Compression
Click to enable
Enable
Debug
Click to enable
Disable
Force NATT
Click to enable
Disable
3.9.1.2 IPSec Tunnels
From navigation panel, select
VPN>>IPSec Tunnels,
click <add>, as shown below.