ZyXEL Communications P2000W User Manual

P-2000W_V2 User’s Guide

Chapter 12 User Web Configurator Screens

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Figure 19   SIP

NAT (Network Address Translation - NAT, RFC 1631) is the translation of the IP address of a 
host in a packet. For example, the source address of an outgoing packet, used within one 
network is changed to a different IP address known within another network. 

In the simplest form, NAT changes the source IP address of a packet received from a device to 
another IP address before forwarding the packet towards the destination. When the response 
comes back, NAT translates the destination address back to the device’s IP address and 
forwards it to the device. 

NAT routers are commonly used to translate private (or internal) IP addresses in packet 
headers to public (or external) IP addresses and vice versa. A NAT router maps a private IP 
address and port pair to a public IP address and port, and whenever the NAT router receives a 
packet with that public IP address and port, it knows how to reroute the packet back to the 
private IP address and port.

Table 11   SIP 

SIP PROXY

Proxy IP Address

This field displays the IP address or domain name of your SIP proxy 

server.

User Account

Registrar Username

This field displays the username as supplied by your VoIP provider to 

access the SIP server.

Local Name

This field displays the name used to interoperate with other SIP devices 

and identify your Prestige on a network.

Phone Number

This field displays your telephone number as your VoIP provider gave 

you.

Registration Status

This field displays either Registered or Not Registered depending on 

the success of your Prestige’s connection to the SIP-Server.

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