ZyXEL Communications EX3510-B1 User Manual page 173

Note: The maximum number of open ports for a single rule or all rules is 999.
Note: The sum of trigger ports in all rules must be less than 1000 and every open port range
must be less than 1000. When the protocol is TCP/UDP, the ports are counted twice.
For example:
Figure 101 Trigger Port Forwarding Process: Example
Jane requests a file from the Real Audio server (port 7070).
1
Port 7070 is a "trigger" port and causes the Zyxel Device to record Jane's computer IP address. The Zyxel
2
Device associates Jane's computer IP address with the "open" port range of 6970-7170.
The Real Audio server responds using a port number ranging between 6970-7170.
3
The Zyxel Device forwards the traffic to Jane's computer IP address.
4
Only Jane can connect to the Real Audio server until the connection is closed or times out. The Zyxel
5
Device times out in three minutes with UDP (User Datagram Protocol) or 2 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.
Chapter 11 Network Address Translation (NAT)
EX3510-B1 User's Guide
173