Denwa Communications DW-310P User Manual page 88

Field name
IPSec ALG
FTP ALG
NAT Configuration
explanation
It is an encryption technology. Select it to enable
IPSec ALG, the default is enabled.
FTP is a service of connection layer which can
transform intranet IP into extranet IP when intranet
IP is sending out packet.
Select it to enable FTP ALG, the default is enabled.