TW-H6W1IR ISDN Remote Router
Configuration and Management 87
?? Local Interface – this is the interface corresponding to the Local
IP and Range parameters, in the NAT table, to form local IP
address[es], known only to this interface and the network within.
?? Translation Mode – this toggles choices of four types of NATs.
Static NAT – Maps one global IP address to one local IP
address. After all global IP addresses are assigned, they will
remain static. This option may be necessary for email, web, ftp
servers, etc. where static IP addresses are essential for
operation.
Dynamic NAT – Maps one global IP address to one local IP
address. Global IP addresses will be dynamically reassigned to
different local IP addresses if not currently being used. This
allows a larger number of users to use a small number of IP
addresses.
Static NAPT – One to one mapping of UDP/TCP port
numbers to let packets with specific UDP/TCP port numbers
enter the local IP domain. The NAPT map table will not age.
This option may be necessary for email, web, ftp servers, etc.
where static port numbers are essential for operation. Setting
the global port number to 0 opens port numbers 1024 to
65535 for the designated local IP address, creating a visible
computer. This allows a computer to be freely accessed by
other computers on the Internet, which is necessary for some
applications to function correctly when using NAPT, including
Microsoft NetMeeting, CUSeeMe, etc.
Dynamic NAPT - One to one mapping of UDP/TCP port
numbers. The NAPT map table will age. This option allows
many hosts to use a single, globally unique IP address.
