Operation Manual

Chapter 11 Network Address Translation (NAT)
VMG/XMG Series User’s Guide
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Figure 135 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 Zyxel Device to record Jane’s computer IP address. The Zyxel
Device associates Jane's computer IP address with the "open" port range of 6970-7170.
3 The Real Audio server responds using a port number ranging between 6970-7170.
4 The Zyxel Device 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 Zyxel
Device times out in three minutes with UDP (User Datagram Protocol) or two hours with TCP/IP (Transfer
Control Protocol/Internet Protocol).
Click Network Setting > NAT > Port Triggering to open the following screen. Use this screen to view your
Zyxel Device’s trigger port settings.
Figure 136 Network Setting > NAT > Port Triggering
DSL