Sua (Single User Account) Versus Nat; Sip Alg; Table 45 Nat Mapping Types - ZyXEL Communications P660HW-DX V2 - V3.40 User Manual

Chapter 8 Network Address Translation (NAT) Screens
The following table summarizes these types.

Table 45 NAT Mapping Types

TYPE
One-to-One
Many-to-One (SUA/PAT)
Many-to-Many Overload
Many-to-Many No Overload
Server

8.2 SUA (Single User Account) Versus NAT

SUA (Single User Account) is a ZyNOS implementation of a subset of NAT that supports two
types of mapping, Many-to-One and Server. The ZyXEL Device also supports Full
Feature NAT to map multiple global IP addresses to multiple private LAN IP addresses of
clients or servers using mapping types as outlined in
• Choose SUA Only if you have just one public WAN IP address for your ZyXEL Device.
• Choose Full Feature if you have multiple public WAN IP addresses for your ZyXEL
Device.

8.3 SIP ALG

Some applications, such as SIP, cannot operate through NAT (are NAT un-friendly) because
they embed IP addresses and port numbers in their packets' data payload.
Some NAT routers may include a SIP Application Layer Gateway (ALG). An Application
Layer Gateway (ALG) manages a specific protocol (such as SIP, H.323 or FTP) at the
application layer.
A SIP ALG allows SIP calls to pass through NAT by examining and translating IP addresses
embedded in the data stream.
When the ZyXEL Device registers with the SIP register server, the SIP ALG translates the
ZyXEL Device's private IP address inside the SIP data stream to a public IP address. You do
not need to use STUN or an outbound proxy if your ZyXEL Device is behind a SIP ALG.
132
IP MAPPING
ILA1 IGA1
ILA1 IGA1
ILA2 IGA1
...
ILA1 IGA1
ILA2 IGA2
ILA3 IGA1
ILA4 IGA2
...
ILA1 IGA1
ILA2 IGA2
ILA3 IGA3
...
Server 1 IP IGA1
Server 2 IP IGA1
Server 3 IP IGA1
Table 45 on page 132.
P-660HW-Dx v2 User's Guide