Gigaset C450 IP Manual page 62

time, page 61), so that the
NAT refresh
entry stays in the routing table.
For outgoing calls
The phone needs its public address in
order to receive caller voice data.
There are two possibilities:
u
The phone requests the public address
from a STUN server on the Internet
(Simple Transversal of UDP over NAT).
STUN can only be used with asymmet-
ric NATs and non-blocking firewalls.
u
The phone does not direct the connec-
tion request to the SIP proxy but to an
outbound proxy on the Internet that
supplies the data packets along with
the public address.
The STUN server and outbound proxy are
used alternately to work around the NAT/
firewall in the router.
STUN enabled
Click on Yes if you want your phone to
use STUN as soon as it is used on a
router with asymmetric NAT.
STUN server
Enter the (fully-qualified) DNS name or
the IP address of the STUN server on
the Internet.
If you selected the option
STUN enabled field, you must enter a
STUN server here.
STUN port
Enter the number of the communica-
tion port on the STUN server. The
default port is 3478.
STUN refresh time
Enter the time intervals at which the
phone should repeat the registration
with the STUN server. The repeat is
required so that the entry of the phone
in the tables of the STUN server is
retained
Ask your VoIP provider for the
refresh time.
The default is 240 seconds.
If you enter 0 seconds, the registration
will not be repeated periodically.
NAT refresh time
Outbound proxy mode
in the
Yes
Outbound proxy
Outbound proxy port
STUN
Specify the intervals at which you want
the phone to update its entry in the
NAT routing table. Specify an interval in
seconds that is a little smaller than the
NAT session timeout.
As a rule you should not change the
preconfigured value for the
time.
Specify when the outbound proxy
should be used.
Always
All signalling and voice data sent by the
phone is sent to the outbound proxy.
Auto
Data sent by the phone is only sent to
the outbound proxy when the phone is
connected to a router with symmetric
NAT or blocking firewall. If the phone is
phone is behind an asymmetric NAT,
the STUN server is used.
If you have set STUN enabled
have not entered a STUN server, the
outbound proxy is always used.
Never
The outbound proxy is not used.
If you do not make an entry in the
bound proxy field, the phone behaves
independently of the selected mode,
just as with Never.
Enter the (fully qualified) DNS name or
the IP address of your provider's out-
bound proxy.
Please note:
With many providers, the outbound proxy is
identical to the SIP proxy.
Enter the number of the communica-
tion port used by the outbound proxy.
The default port is 5060.
Web configurator
NAT refresh
= No or
Out-
61