Two Points To Remember About Trigger Ports; Nat Advanced Screen; Figure 93 Trigger Port Forwarding Process: Example - ZyXEL Communications NBG-460N User Manual

Figure 93 Trigger Port Forwarding Process: Example

1 Jane requests a file from the Real Audio server (port 7070).
2 Port 7070 is a "trigger" port and causes the NBG460N to record Jane's computer IP
address. The NBG460N associates Jane's computer IP address with the "incoming" port
range of 6970-7170.
3 The Real Audio server responds using a port number ranging between 6970-7170.
4 The NBG460N forwards the traffic to Jane's computer IP address.
5 Only Jane can connect to the Real Audio server until the connection is closed or times
out. The NBG460N times out in three minutes with UDP (User Datagram Protocol), or
two hours with TCP/IP (Transfer Control Protocol/Internet Protocol).

11.5.2 Two Points To Remember About Trigger Ports

1 Trigger events only happen on data that is going coming from inside the NBG460N and
going to the outside.
2 If an application needs a continuous data stream, that port (range) will be tied up so that
another computer on the LAN can't trigger it.

11.6 NAT Advanced Screen

To change your NBG460N's trigger port settings, click Network > NAT > Advanced. The
screen appears as shown.
Only one LAN computer can use a trigger port (range) at a time.
NBG460N User's Guide
Chapter 11 Network Address Translation (NAT)
143