Grandstream WP820 : Administration Guide : Page 36

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WP820 Administration Guide

Version 1.0.5.5

NAT Traversal

Specifies which NAT traversal mechanism will be enabled on the phone. It can be

selected from the dropdown list:

• NAT NO

• STUN

• Keep-alive

• Auto

• OpenVPN

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 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 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 “OpenVPN”.

The default setting is "NAT NO".

Proxy-Require

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.

Account/SIP Settings

SIP Basic Settings

SIP Registration

Allows the phone to send SIP REGISTER messages to the proxy/server.

The default setting is "Yes".

Unregister before

New Registration

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 SIP server. The default setting is "Instance".

Register Expiration

(m)

Configures the time period (in minutes) in which the phone refreshes its

registration with the specified registrar. The default setting is 60. The maximum

value is 64800 (about 45 days).