Grandstream Networks GXP21 Series User Manual page 35

SIP T2 Interval
SIP Transport
Check Domain
Certificates
Remove OBP from
Route
Validate Incoming
Messages
Support SIP Instance ID Selects whether or not SIP Instance ID is supported.
NAT Traversal (STUN)
SUBSCRIBE for MWI:
PUBLISH for Presence
Proxy-Require
Voice Mail UserID
Send DTMF
DTMF Payload Type
Early Dial
Dial Plan Prefix
Grandstream Networks, Inc.
RFC 3261 SIP T2 timer. Default is 0.5 seconds.
Choose SIP Transport between UDP and TCP. Default is UDP.
When set to Yes/Enabled, it will check the domain certificate as defined in
RFC5922
The SIP Extension notifies the SIP server that it is behind a NAT/firewall.
This configuration selects whether or not the incoming messages should be
validated.
This parameter activates the NAT traversal mechanism. If activated (by choosing
"Yes") and a STUN server is also specified, the phone performs according to the
STUN client specification. Using this mode, the embedded STUN client detects if
and what type of NAT/Firewall configuration is used. If the detected NAT is a Full
Cone, Restricted Cone, or a Port-Restricted Cone, the phone will use its mapped
public IP address and port in all of its SIP and SDP messages. If the NAT
Traversal field is set to "Yes" with no specified STUN server, the GXP will
periodically (every 20 seconds or so) send a blank UDP packet (with no payload
data) to the SIP server to keep the "hole" on the NAT open.
Default is No. When set to "Yes" a SUBSCRIBE for Message Waiting Indication
will be sent periodically.
Enable Presence feature.
SIP Extension to notify SIP server that the unit is behind the NAT/Firewall.
When configured, user can access messages by pressing "MSG" button. This ID
is usually the VM portal access number.
This parameter specifies the mechanism to transmit DTMF digit. There are 3
supported modes: in audio which means DTMF is combined in audio signal (not
very reliable with low-bit-rate codec), via RTP (RFC2833), or via SIP INFO.
Sends DTMF using RFC2833. The default is 101.
Default is No. Use only if proxy supports 484 responses.
Sets the prefix added to each dialed number.
GXP21xx User Manual
Firmware 1.0.1.26
Page 35 of 42
Last Updated: 11/2010