Account - Sip Settings; Table 25: Account - Sip Settings - Grandstream Networks GAC2500 Administration Manual

NAT Traversal
Proxy-Require

Account - SIP Settings

SIP Registration
Unregister before new
registration
one result, it should be set to "SRV" or "NATPTR/SRV".
The default setting is "A Record".
Specifies which NAT traversal mechanism will be enabled on the phone
system. It can be selected from the dropdown list:
•
NAT NO
•
STUN
•
Keep-alive
•
UPnP
•
Auto
•
VPN
If the outbound proxy is configured and used, it can be set to "NAT NO".
If set to "STUN" and STUN server is configured, the phone system will
periodically send STUN message to the SUTN server to get the public
IP address of its NAT environment and keep the NAT port open. STUN
will not work if the NAT is symmetric type.
If set to "Keep-alive", the phone system will send the STUN packets to
maintain the connection that is first established during registration of the
phone. The "Keep-alive" packets will fool the NAT device into keeping
the connection open and this allows the host server to send SIP requests
directly to the registered phone.
If it needs to use OpenVPN to connect host server, it needs to set it to
"VPN". If the firewall and the SIP device behind the firewall are both able
to use UPNP, it can be set to "UPNP". The both parties will negotiate to
use which port to allow SIP through. The default setting is "Keep-alive".
Adds the Proxy-Required header in the SIP message. It is used to
indicate proxy-sensitive features that must be supported by the proxy.
Do not configure this parameter unless this feature is supported on the
SIP server.

Table 25: Account - SIP Settings

Allows the phone system to send SIP REGISTER messages to the
proxy/server. The default setting is "Yes".
Controls whether to clear SIP user's information by sending un-register
request to the proxy server. When set to "All", the un-registration is
performed by sending a REGISTER message with "Contact" header set
to * and Expires=0 parameters to the SIP server when the phone starts
pre-registration after rebooting. If set to "Instance", the phone only cleans
the current SIP user's info by sending REGISTER message with "Contact"
header set to concerned SIP user's info and Expires=0 parameters to the
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