Grandstream Networks GRP261X Administration Manual page 45

NAT Traversal
Proxy-Require
Use SBC
Account x  SIP Settings  Basic Settings
TEL URI
SIP Registration
Unregister On Reboot
Register Expiration
This parameter configures whether the NAT traversal mechanism is
activated. Users could select the mechanism from No, STUN, Keep-alive,
UPnP, Auto or VPN. The default setting is "Auto".
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. Set this to "VPN" if OpenVPN is used.
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.
Indicate whether or not an SBC server is used. If users want to work under
SBC associated with 3CX, they should enable this feature to have better
communication with the 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 "Disabled".
Selects whether the phone will send SIP Register messages to the
proxy/server. The default setting is "Yes".
Allows the SIP user's registration information to be cleared when the phone
reboots. The SIP REGISTER message will contain "Expires: 0" to unbind the
connection. Three options are available: The default setting is "No".

If set to "All", 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.

If set to "Instance", the SIP user will be unregistered on current phone
only.

If set to "No", the phone will not unregister the SIP account when
rebooting.
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).
GRP261x/GRP2624/GRP2634 Administration Guide
Version 1.0.5.48
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