Cisco 521SG - Unified IP Phone VoIP Administration Manual page 246

Cisco SPA IP Phone Field Reference
SIP Tab
Cisco Small Business SPA300 Series, SPA500 Series, and WIP310 IP Phone Administration Guide
Parameter
Insert VIA rport
Substitute VIA Addr
Send Resp To Src Port
STUN Enable
STUN Test Enable
STUN Server
Description
Inserts the rport parameter into the VIA header of
SIP responses if the received-from IP and VIA
sent-by IP values differ. Select yes or no from the
drop-down menu.
Defaults to no.
Lets you use NAT-mapped IP:port values in the
VIA header. Select yes or no from the drop-down
menu.
Defaults to no.
Sends responses to the request source port
instead of the VIA sent-by port. Select yes or no
from the drop-down menu.
Defaults to no.
Enables the use of STUN to discover NAT
mapping. Select yes or no from the drop-down
menu.
Defaults to no.
If the STUN Enable feature is enabled and a valid
STUN server is available, the SPA9000 can
perform a NAT-type discovery operation when it
powers on. It contacts the configured STUN
server, and the result of the discovery is reported
in a Warning header in all subsequent REGISTER
requests. If the SPA9000 detects symmetric NAT
or a symmetric firewall, NAT mapping is disabled.
Defaults to 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.
A
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