ZyXEL Communications Prestige 645R - Manual (Page 57)

Prestige 645 ADSL Internet Access Router
Internet Access 3-15
Figure 3-8 Single User Account Topology
The IP address for the SUA can be either fixed or dynamically assigned by the ISP. In addition, you can
designate servers; for example, a web server and a telnet server, on your local network and make them
accessible to the outside world. If you do not define any server, SUA offers the additional benefit of firewall
protection. If no server is defined, all incoming inquiries will be filtered out by your Prestige, thus
preventing intruders from probing your network. Your Prestige accomplishes this address sharing by
translating the internal LAN IP addresses to a single address that is globally unique on the Internet. For more
information on IP address translation, refer to RFC 1631, The IP Network Address Translator (NAT).
3.11.1 Advantages of SUA
In summary:
SUA is a cost-effective solution for small offices to access the Internet or other remote TCP/IP
networks.
SUA supports servers to be accessible to the outside world.
SUA can provide firewall protection if you do not specify a server. All incoming inquiries will be
filtered out by your Prestige.