Nat Mapping With Stun Parameters; Determine Symmetric Or Asymmetric Nat - Cisco 8800 Series Manual

NAT Mapping with STUN Parameters

Step 6
Click Submit All Changes.
What to do next
Configure the firewall settings on your router to allow SIP traffic.
NAT Mapping with STUN Parameters
The following table defines the function and usage of NAT mapping with STUN parameters in the NAT
Support Parameters section under the Voice>SIP tab in the phone web interface. It also defines the syntax of
the string that is added in the phone configuration file with XML(cfg.xml) code to configure a parameter.
Table 81: NAT Mapping with STUN Parameters
Parameter
STUN Enable
STUN Server

Determine Symmetric or Asymmetric NAT

STUN does not work on routers with symmetric NAT. With symmetric NAT, IP addresses are mapped from
one internal IP address and port to one external, routable destination IP address and port. If another packet is
sent from the same source IP address and port to a different destination, a different IP address and port number
Cisco IP Phone 8800 Series Multiplatform Phone Administration Guide for Release 11.3(1) and Later
392
Description
Enables the use of STUN to discover NAT mapping.
Perform one of the following:
• In the phone configuration file with
XML(cfg.xml), enter a string in this format:
<STUN_Enable ua="na">Yes</STUN_Enable>
• In the phone web page, set to Yes to enable the
feature.
Allowed values: Yes and No.
Default: No
IP address or fully-qualified domain name of the
STUN server to contact for NAT mapping discovery.
You can use a public STUN server or set up your own
STUN server.
Perform one of the following:
• In the phone configuration file with
XML(cfg.xml), enter a string in this format:
<STUN_Server ua="na"/>
• In the phone web page, enter an IP address or
fully-qualified domain name of the STUN server.
Allowed values:
Default: Blank
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