Advantages Of Sua - ZyXEL Communications Prestige 128 Plus User Manual

Prestige 128+ ISDN Router
The IP address for the SUA can be either fixed or dynamically assigned when a
call is connected. In addition, you can designate servers, e.g., 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 and 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).

3.5.1 Advantages of SUA

In summary:
SUA is a cost-effective solution for small offices with less than 20 hosts 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.
UDP and TCP packets can be routed. In addition, partial ICMP, including
echo and trace route, is supported.
3-14 Internet Access