Grandstream Networks GRP261 Series Administration Manual page 26

DNS SRV Failover Mode
Register Before DNS SRV Failover
Primary IP
Backup IP 1
Backup IP 2
NAT Traversal
Proxy-Require
Use SBC
Account x �� SIP Settings
Basic Settings
SIP Registration
re-tries.
If SIP server is already an IP address, phone will use it directly even "User
Configured IP" is selected.
Configures the preferred IP mode for DNS SRV. If set to "default", the first IP
from the query result will be applied. If set to "Saved one until DNS TTL",
previous IP will be applied before DNS timeout is reached. If set to "Saved one
until no response", previous IP will be applied even after DNS timeout until it
cannot respond.
● Default
If the option is set with "default", it will again try to send register messages to
one IP at a time, and the process repeats.
● Saved one until DNS TTL
If the option is set with "Saved one until DNS TTL", it will send register
messages to the previously registered IP first. If no response, it will try to send
one at a time for each IP. This behavior lasts if DNS TTL (time-to-live) is up.
● Saved one until no responses
If the option is set with "Saved one until no responses", it will send register
messages to the previously registered IP first, but this behavior will persist
until the registered server does not respond.
Indicates whether a REGISTER request will be initiated when a server failover
occurred under DNS SRV mode.
Default setting is No.
Configures the primary IP address where the phone sends DNS query to when
"Use Configured IP" is selected for DNS mode.
Configures the backup IP 1 address where the phone sends DNS query to
when "Use Configured IP" is selected for DNS mode.
Configures the backup IP 2 address where the phone sends DNS query to
when "Use Configured IP" is selected for DNS mode.
Configures whether NAT traversal mechanism is activated. Please refer to
user manual for more details.
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.
Configures whether a SBC server is used. Note: If enabled, make sure an
outbound proxy is set up.
Selects whether the phone will send SIP Register messages to the
proxy/server. The default setting is "Enabled".