ZyXEL Communications PRESTIGE 2000W V2, User Manual

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P-2000W_V2 User’s Guide
Chapter 12 User Web Configurator Screens 83
Figure 19 SIP
12.11 NAT
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
LABEL DESCRIPTION
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.