D-Link DI-1162 - Manual (Page 97)

DI-1162 Remote Access Router
Configuration and Management 87
address and port. Notice that the global address will be the external IP
address of the global interface.
•
Port – this is a destination port number, used by TCP and UDP, to
de-multiplex the incoming IP packet.
In the above example, incoming packets with the global destination IP
Address (211.11.22.2) and global destination TCP/UDP port (21) will
be translated to a packet with the local destination IP Address (1.1.1.5)
and local TCP/UDP port (21).
Port 21 is assigned to FTP servers. Please see Appendix D for more
commonly assigned port numbers, or RFC 1700 for a more complete
list.
Configure NAPT for Special Ap[plication]s
Some applications programs that are used over the Internet such as
Microsoft NetMeeting, Diablo, CU See Me and Xwindows send
information to a certain port number or within a specified range of port