Port Triggering Help
Some applications require multiple connections, like Internet games,
video conferencing, Internet telephoning and so on. These applications
cannot work with a pure NAT router. Port Triggering is used for some of
these applications that can work with an NAT router.
Once configured, operation is as follows:
- A local host makes an outgoing connection to an external host using a destination port number defined in the Trigger Port field.
- The router records this connection, opens the incoming port or ports associated with this entry in the Port Triggering table, and associates them with the local host.
- When necessary the external host will be able to connect to the local host using one of the ports defined in the Incoming Ports field.
Rules:
- Trigger Port - The port for outgoing traffic. An outgoing connection using this port will "Trigger" this rule.
- Trigger Protocol - The protocol used for Trigger Ports, either TCP, UDP, or All (all protocols support by the router).
- Incoming Ports - The port or port range used by the remote
system when it responds to the outgoing request. A response using one
of these ports will be forwarded to the PC which triggered this rule.
You can input at most 5 groups of ports (or port section). Every group
of ports must be apart with ",". For example, 2000-2038, 2046,
2050-2051, 2085, 3010-3030.
- Incoming Protocol - The protocol used for Incoming Ports Range, either TCP, UDP, or ALL (all protocols support by the router).
- Status - The status of this entry, "Enabled" means the Port Triggering entry is enabled.
- Common Applications - Some popular applications already listed in the pull-down list.
To add a new rule, enter the following data on the Port Triggering screen:
- Click the Add New.. button.
- Enter a port number used by the application to send an outgoing request.
- Select the protocol used for Trigger Port from the pull-down list, either TCP, UDP, or All.
- Enter the range of port numbers used by the remote system when it responds to the PC's request.
- Select the protocol used for Incoming Ports range from the pull-down
list, either TCP, UDP, or All.
- Select the Enabled in the Status pull-down list.
- Click the Save button to save the new rule.
There are many popular applications in the Common Application list. You can select it and the ID, then click the Copy to button, the application will fill in the Trigger Port, incoming Ports range boxes and select the Enable checkbox. It has the same effect as adding a new rule.
To modify or delete an existing entry:
- Find the desired entry in the table.
- Click Modify or Delete as desired on the Modify column.
Click the Enable All button to make all entries enabled.
Click the Disable All button to make all entries disabled.
Click the Delete All button to delete all entries.
Click the Next button to go to the next page and Click the Previous button to return to the previous page.
Note:
- When the trigger connection is released, the according opening ports will be closed.
- Each rule allowed to be used only by one host on LAN synchronously.
The trigger connection of other hosts on LAN will be refused.
- Incoming Ports range cannot overlap each other.