Configuring Your Gateway
Assume, for example, that to use H.323 in a Net Meeting application, a local client starts a
session A to a remote host. The remote host uses session A to communicate with the local
host, but it also could initiate another session B back to the local host. Since there is only
session A recorded in the NAT session table when the local host starts the communication,
session B is treated as an illegal access from the outside and is blocked. Using the Special
Application menu, you can configure the Gateway to co-relate sessions A and B and
automatically open the port for the incoming session B.
The maximum allowed triggers is 50. To enable/disable the special application function,
users can check/uncheck the Enable Triggering checkbox and press the APPLY icon to
make it effective without reboot.
To display the Special Applications menu, click Firewall in the menu bar and then click the
Special Application submenu. Figure 29 shows an example of the menu.
Figure 29. Special Applications Menu
To enable port triggering:
1. In the Special Application menu, check Enable Triggering and click the Apply button. The
Trigger Table becomes available.
2. Click the Add button below the table. The Trigger menu appears (see Figure 30).
50
SMCD3GN Wireless Cable Modem Gateway User Manual