Denwa Communications DW-610G User Manual page 88

Field name
IPSec ALG
FTP ALG
PPTP ALG
Shows the NAT TCP mapping table
Shows the NAT UDP mapping table
NAT Configuration
explanation
It is an encryption technology. Select it to enable IPSec
ALG, the default is enable
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 enable
Select it enable PPTP ALG, the default is enable