Grandstream Networks DP750 Administration Manual page 47

DNS Mode
Selects DNS mode to use for the client to look up server. One mode can be chosen.
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Default is A Record.
Primary IP Specifies primary IP address where the base sends DNS query to, when "Use
Configured IP" is selected for DNS mode.
Backup IP 1 Specifies backup IP 1 address where the base sends DNS query to, when "Primary
IP" is not responding.
Backup IP 2 Specifies backup IP 2 address where the base sends DNS query to, when "Backup
IP 1" is not responding.
Enables/disables NAT traversal mechanism. If activated (by choosing "STUN") and
NAT Traversal
a STUN server is also specified (Maintenance  Network Settings  STUN
Settings); the base performs according to STUN client specification. Under this
mode, embedded STUN client will detect if and what type of firewall/NAT is being
used. If detected NAT is a Full Cone, Restricted Cone, or a Port-Restricted Cone,
the base will use its mapped public IP address and port in all of its SIP and SDP
messages. If NAT Traversal field is set to "Keep Alive", the base will periodically
(every 20 seconds) send a blank UDP packet (with no payload data) to SIP proxy
to keep the "ping hole" on the NAT open.
Use NAT IP Defines NAT IP address used in SIP/SDP messages. It should only be used if
required by ITSP.
Proxy-Require Determines a SIP Extension to notify the SIP server that the base is behind a
NAT/Firewall.
SIP Settings – Basic Settings
SIP transport Selects transport protocol for SIP packets; UDP or TCP or TLS. Make sure your
SIP server or network environment supports SIP over the selected transport
method. Default is UDP.
SIP Registration Controls whether to send SIP REGISTER messages to the proxy server. Device
may not be able to make/receives calls if disabled. Default is Yes.
A Record: resolves IP Address of target according to domain name.
SRV: DNS SRV resource records indicate how to find services for various
protocols.
NAPTR/SRV: Naming Authority Pointer according to RFC 2915.
Use Configured IP: If selected, please fill in Primary IP, Backup IP 1 and
Backup IP 2 to be used for server look up.
DP750/DP720 Administration Guide
Version 1.0.11.4
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