Modifying The Nat Settings - Linksys SPA921 - Cisco - IP Phone Installation And Configuration Manual

Maintaining Your SPA9000 Voice System
Using the Advanced Features Menu
NOTE
SPA9000 Voice System Installation and Configuration Guide for Setup Wizard

Modifying the NAT Settings

The SPA9000 NAT Traversal page helps you to modify the SPA9000 NAT traversal
mechanisms. You can find this page under Main Menu > Advanced Features > NAT
Settings.
Modify your NAT settings ONL Y with guidance from your ITSP.
Setting an External IP Address (EXT IP)
Configuring NAT mapping in the SPA9000 is recommended only if the ITSP
network does not provide a Session Border Controller functionality. In this case,
you can set an external (public) IP address to perform a static (permanent)
mapping on SPA9000. This solution requires that the following conditions are met:
•
The external (public) IP address is static.
•
The router uses a symmetric NAT mechanism.
•
The LAN switch is configured to enable Spanning Tree Protocol and Port Fast
on the ports to which the SPA9000 and the SPA9xx phones are connected.
See "Connecting and Configuring the Switch," on page
6
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