8820IP Phone User Manual_ SIP (V1.44)
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please select an item from dropdown list.
n
disable:
Select this item when the sip proxy server and IP phone in
the same LAN, or the sip proxy system supports the IP phone working
behind the LAN.
n
enable:
When the system does not support IP phone working behind
the LAN, please select this item to search public IP address of the
NAT device. With this item selected, “
nat addr
”
field will be activated.
Besides, port mapping (port forwarding) needs to be properly set up
on NAT device.
n
stun:
Select this item with Stun server used according to requirement
of system. With this item selected,
nat addr
field is activated.
●
nat addr:
When “
nat traversal
” is set to “
enable
”, please put the domain
name of the servers ( These web server helps to find out the public IP of
the NAT device) into “
nat addr
”, such as
www.whatismyip.com
.
When
“
nat traversal
” is set to “
stun
”, please put the URI of the stun server
into “
nat addr
”, in the format as “domain name/IP address : service port”.
The default service port for stun is 3478.
●
nat ttl:
When IP phone sit behind a NAT device, it will send packets to
server every “
nat ttl
” seconds to keep the port mapping on the NAT