What is the difference between NAT and SUA?
NAT is a generic name defined in RFC 1631 ‘The IP Network Address Translator (NAT)’. SUA (Internet Single User Account) is ZyXEL’s implementation and trade name for functioning PAT which is a specific type of NAT. SUA( or PAT for NAT) translates address into port mapping. The primary motivation for RFC 1631 is that there is not enough IP address to go around. In addition, many corporations simply did not bother to obtain legal (globally unique) IP addresses for their networks and now finding themselves unable to connect to the Internet. Basically, NAT is a process of translating one address to another. A NAT implementation can be as simple as substituting an IP address with another. This allows a network to rectify the illegal address problem mentioned above without going through each and every host.
