Linksys SPA921 - Cisco - IP Phone Installation And Configuration Manual page 116

Maintaining Your SPA9000 Voice System
Using the Advanced Features Menu
!
CAUTION
STEP 1
STEP 2
STEP 3
SPA9000 Voice System Installation and Configuration Guide for Setup Wizard
Using a STUN Server
Configuring NAT mapping in the SPA9000 is recommended only if the ITSP
network does not provide a Session Border Controller functionality. You can use
STUN as a mechanism to discover the NAT mapping in the SPA9000. This solution
requires that the following conditions are met:
•
The external (Public) IP address is assigned dynamically by the network.
•
The router uses an asymmetric NAT mechanism.
STUN is considered a method of last resort and should be used only if the other
methods are unavailable. STUN is a viable option only if your router uses
asymmetric NAT.
Enter the STUN Server's IP address in the STUN Server field. Example 69.231. 1 .88
Click Next to preview the parameters the Wizard will send to the SPA9000.
Click OK to close the parameter preview dialog box and cause the Wizard to
submit the changes to the SPA9000 and reboot it.
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