1.1.10.2 NAT (Network Address Translation) Setup
This section provides information about configuring a router that uses NAT.
Router
PC
Private IP address:
192.168.228.11
SIP Cordless Phone
Private IP address:
192.168.228.12
Switching
Hub
Global IP address:
xxx.yyy.zzz.127
Internet
If the unit is connected to a network that uses a NAT router and a private IP address is assigned to each
terminal on the network, depending on your phone system’s setup, you might need to configure the unit and
router so as to use NAT Traversal techniques.
If your phone system dealer provides an outbound proxy service that supports NAT Traversal, you need only
to set the IP address of the SIP outbound proxy server to the unit—no other settings are necessary.
However, depending on the phone system of the outbound proxy service, no setting may be necessary because
private IP addresses are automatically translated into global IP addresses by the outbound proxy server.
For details about the outbound proxy service, consult your phone system dealer.
When TCP is used to transport the SIP messages, you must always configure the devices for NAT Traversal.
To configure NAT Traversal, you must have the following information:
•The global IP address of the router.
•The port numbers you will specify for [Source Port] and [External RTP Port] through the Web user
interface, so that you can configure the appropriate port forwarding settings.
Note
•Because the IP address of the router needs to be set in the unit, the IP address must be static.

SIP Setup

It might be necessary to manually set the router’s global IP address and reception port number in the unit.
In addition, it might also be necessary to configure the port forwarding settings of the router so that packets
sent from an outside network are sent to the unit. These settings are required for each individual line. For
details about Web user interface programming, see 3.4.5 Static NAPT Settings and 3.6.2.5 SIP Source
Port.
Document Version 2010.03.15 Administrator Guide 29
1.1.10 Other Network Settings