Siemens Gigaset S685 IP Manual page 185

Registrar server port
Enter the communication port used in the registrar. It is mainly port 5060 that
is used.
Registration refresh time
Enter the time intervals (in seconds) at which the phone should repeat the reg-
istration with the VoIP server (SIP proxy) (a request will be sent to establish a
session). The repeat is required so that the entry of the phone in the tables of
the SIP proxy is retained and the phone can therefore be reached. The repeat
will be carried out for all activated VoIP phone numbers.
The default is 180 seconds.
If you enter 0 seconds, the registration will not be repeated periodically.
Area: Network
Please note
If you have downloaded the general settings for your VoIP provider from the
Gigaset configuration server (
be preset with the data from the download (e.g. the settings for the STUN
server and outbound proxy).
If your phone is connected to a router with NAT (Network Address Translation)
and/or a firewall, you must select some settings in this area so that your phone
can be reached from the Internet (i.e. can be addressed).
Through NAT, the IP addresses of subscribers in the LAN are concealed behind
the public IP address of the router.
For incoming calls
If port forwarding is activated or a DMZ is set up for the phone on the router,
no special settings are required for incoming calls.
If this is not the case, an entry in the NAT routing table (in the router) is neces-
sary in order for the phone to be reached. This entry is created when the phone
is registered with the SIP service. In the interest of security, this entry is auto-
matically deleted at certain intervals (session timeout). The phone must there-
fore confirm its registration at certain intervals (
Page 184) 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:
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 connection 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 alternatively to work around the
NAT/firewall in the router.
Web configurator – setting the phone using a PC
£
Page 180), then some fields in this area will
£
NAT refresh time on
183