Gigaset SX763 User Manual page 66

Configuring Advanced Settings
Using port forwarding (the forwarding of requests to particular ports) the router is
forced to send requests from the Internet for a certain service, for example a game, to
the appropriate port(s) on the PC on which the game is running.
Port triggering is a special variant of port forwarding. Unlike port forwarding, the
Gigaset SX763 WLAN dsl forwards the data from the port block to the PC which has pre-
viously sent data to the Internet via a certain port (trigger port). This means that
approval for the data transfer is not tied to one specific PC in the network, rather to the
port numbers of the required Internet service.
Where configuration is concerned, this means:
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You have to define a so-called trigger port for the application and also the protocol
(TCP or UDP) that this port uses. You then assign the public ports that are to be
opened for the application to this trigger port.
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The router checks all outgoing data for the port number and protocol. If it identifies
a match of port and protocol for a defined trigger port, then it will open the assigned
public ports and notes the IP address of the PC that sent the data. If data comes back
from the Internet via one of these public ports, the router allows it through and
directs it to the appropriate PC. A trigger event always comes from a PC within the
local network. If a trigger port is addressed from outside, the router simply ignores it.
Note:
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An application that is configured for port triggering can only be run by one user in
the local network at a time.
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As long as the public ports are open, they can be used by unauthorised persons to
gain access to a PC in the local network.
When the Gigaset SX763 WLAN dsl is supplied, the
Translation) is activated, i.e. all IP addresses of PCs in the local network are converted to
the router's public IP address when accessing the Internet.
You can use the NAT settings to configure the Gigaset SX763 WLAN dsl to carry out the
following tasks:
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Set up the Gigaset SX763 WLAN dsl as a virtual server by configuring Port Forward-
ing (page 67),
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Open the firewall for selected PCs (page 69).
Note:
For the functions described below, the IP addresses of the PCs must remain
unchanged. If the IP addresses of the PCs are assigned via the DHCP server of the
Gigaset SX763 WLAN dsl, you must select Never expires (page 74) as the setting in
the Local Network menu entry for the Lease time or assign static IP addresses for the
PCs.
66
NAT function (Network Address