Grandstream Networks GXP2140 User Manual page 46

Account x -> Network Settings
DNS Mode
NAT Traversal
Proxy-Require
Account x -> SIP Settings -> Basic Settings
TEL URI
SIP Registration
Unregister On Reboot
Register Expiration
Reregister Before
FIRMWARE VERSION 1.0.0.17
Asterisk server, 8500 could be used.
This parameter controls how the Search Appliance looks up IP addresses for
hostnames. There are four modes: A Record, SRV, NATPTR/SRV, Use
Configured IP. The default setting is "A Record". If the user wishes to locate
the server by DNS SRV, the user may select "SRV" or "NATPTR/SRV". If "Use
Configured IP" is selected, please fill in the three fields below:

Primary IP: The primary IP address where the phone sends DNS query
to;

Backup IP 1;

Backup IP 2.
This parameter configures whether the NAT traversal mechanism is activated.
Users could select the mechanism from No, STUN, Keep-Alive, UPnP, Auto or
VPN. If set to "STUN" and STUN server is configured, the phone will route
according to the STUN server. If NAT type is Full Cone, Restricted Cone or
Port-Restricted Cone, the phone will try to use public IP addresses and port
number in all the SIP&SDP messages. The phone will send empty SDP packet
to the SIP server periodically to keep the NAT port open if it is configured to be
"Keep-Alive". Configure this to be "No" if an outbound proxy is used. "STUN"
cannot be used if the detected NAT is symmetric NAT.
A SIP Extension to notify the SIP server that the phone is behind a
NAT/Firewall. Do not configure this parameter unless this feature is supported
on the SIP server.
If the phone has an assigned PSTN telephone number, this field should be set
to "User=Phone". Then a "User=Phone" parameter will be attached to the
Request-Line and "TO" header in the SIP request to indicate the E.164
number. If set to "Enable", "Tel:" will be used instead of "SIP:" in the SIP
request. The default setting is "Disable".
Selects whether or not the phone will send SIP Register messages to the
proxy/server. The default setting is "Yes".
If set to "Yes", the SIP user's registration information will be cleared when the
phone reboots. The SIP Contact header will contain "*" to notify the server to
unbind the connection. The default setting is "No".
Specifies the frequency (in minutes) in which the phone refreshes its
registration with the specified registrar. The default value is 60 minutes. The
maximum value is 64800 minutes (about 45 days).
Specifies the time frequency (in seconds) that the phone sends
GXP2140/GXP2160 USER MANUAL Page 46 of 79