Siemens Gigaset C450IP User Manual

Page 61

Web configurator

Gigaset C450 IP / Greek eng / A31008-M1713-T151-3-8U19 / web_server.fm / 24.9.07

Ver

on 4, 16.

09.20

NAT refresh time

, page 60), so that the

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:

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.

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

Yes

in the

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

STUN

refresh time

The default is 240 seconds.
If you enter 0 seconds, the registration

will not be repeated periodically.

NAT refresh time

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

NAT refresh

time

Outbound proxy mode

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

Out-

bound proxy

field, the phone behaves

independently of the selected mode,

just as with

Never

Outbound proxy

Enter the (fully qualified) DNS name or

the IP address of your provider's out-

bound proxy.

Outbound proxy port

Enter the number of the communica-

tion port used by the outbound proxy.

The default port is 5060.

Please note:

With many providers, the outbound proxy is

identical to the SIP proxy.