Yeastar Technology NeoGate TB400 User Manual page 31

Table 4-9 Description of NAT Settings
Items
Enable STUN
STUN Address
STUN Port
External IP Address
External Host
External Refresh Interval
Local Network Identification
NAT Mode
Figure 4-12 NAT Settings
Description
STUN (Simple Traversal of UDP through NATs) is a protocol
for assisting devices behind a NAT firewall or router with
their packet routing.
The STUN server allows clients to find out their public
address, the type of NAT they are behind and the internet
side port associated by the NAT with a particular local port.
This information is used to set up UDP communication
between the client and the VOIP provider and so establish a
call.
STUN Port
The IP address that will be associated with outbound SIP
messages if the system is in a NAT environment.
Alternatively you can specify an external host, and the
system will perform DNS queries periodically.
This setting is only required when your public IP address is
not static. It is recommended that a static public IP address
issued with this system. Please contact your ISP for more
information.
If an external host has been supplied, you may specify how
often the system will perform a DNS query on this host. This
value is specified in seconds.
Used to identify the local network using a network
number/subnet mask pair when the system is behind a NAT
or firewall.
Some examples of this are as follows:
"192.168.0.0/255.255.0.0": All RFC 1918 addresses are
local networks;
"10.0.0.0/255.0.0.0": Also RFC1918;
"172.16.0.0/12":Another RFC1918 with CIDR notation;
"169.254.0.0/255.255.0.0": Zero conf local network.
Please refer to RFC1918 for more information.
Global NAT configuration for the system; the options for this
setting are as follows:
Yes = Use NAT. Ignore address information in the SIP/SDP
headers and reply to the sender's IP address/port.
No = Use NAT mode only according to RFC3581.
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