Cisco 7800 Series Administration Manual page 255

Cisco IP Phone Troubleshooting
Parameter
Insert VIA received
Insert VIA rport
Substitute VIA Addr
Send Resp To Src Port
STUN Enable
STUN Test Enable
STUN Server
EXT IP
Description
Enables to insert the received parameter into the VIA
header of SIP responses if the received-from IP and
VIA sent-by IP values differ.
Default: No
Enables to insert the rport parameter into the VIA
header of SIP responses if the received-from IP and
VIA sent-by IP values differ.
Default: No
Enables the user to use NAT-mapped IP:port values
in the VIA header.
Default: No
Enables to send responses to the request source port
instead of the VIA sent-by port.
Default: No
Enables the use of STUN to discover NAT mapping.
Default: No
If the STUN Enable feature is enabled and a valid
STUN server is available, the phone 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 phone
detects symmetric NAT or a symmetric firewall, NAT
mapping is disabled.
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.
Default: Blank
External IP address to substitute for the actual IP
address of phone in all outgoing SIP messages. If
0.0.0.0 is specified, no IP address substitution is
performed.
If this parameter is specified, phone assumes this IP
address when generating SIP messages and SDP (if
NAT Mapping is enabled for that line).
Default: Blank
Cisco IP Phone 7800 Series Multiplatform Phones Administration Guide
NAT Support Parameters
241