Zhone sia2410r ユーザーガイド

 

Net To Net Technologies SIA2410R User Manual 

 

Net To Net Technologies                                                                                                     40 

 
To connect to the Internet or any other TCP/IP network, a host must have an 
IP address that is unique within that network. The Internet and other large 
TCP/IP networks guarantee the uniqueness of addresses by creating central 
authorities that assign official IP addresses. However, many local networks 
use private IP addresses that are unique only on the local network. To allow a 
host with a private address to communicate with the Internet or another 
networks that requires an official IP address, the SIA2410R can perform a 
service known as Network Address Translation (NAT).  
NAT works as follows: When the local host sends packets to the remote 
network, the SIA2410R automatically translates the host’s private address on 
the local network to an official address on the remote network. When the local 
host receives packets from the remote network, SIA2410R automatically 
translates the official address on the remote network to the host’s private 
address on the local network. 
 
The IP address conversion can be performed in the following three ways: 
1> Static Mapping 

The SIA2410R establish a one-to-one mapping between the private IP 
and public IP. 
This translation is used when the connection to the internal network 
is attempted from the outside. It is often used when a server on the 
LAN needs to be accessed from the WAN. 

Usually, this method takes a dynamic n:n translation. The translations 
between the local network and the Internet or remote network are 
dynamic.