ZyXEL Communications P-873HNU-51B, User Manual

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Chapter 11 Network Address Translation (NAT)
P-873HNU(P)-51B User’s Guide
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Figure 64
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 VDSL Router to record Jane’s computer IP address. The
VDSL Router 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 VDSL Router 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
VDSL Router times out in three minutes with UDP (User Datagram Protocol) or two hours with TCP/
IP (Transfer Control Protocol/Internet Protocol).
Click Network Settings > NAT > Port Triggering to open the following screen. Use this screen
to view your VDSL Router’s trigger port settings.
Figure 65
Network Settings > NAT > Port Triggering
The following table describes the labels in this screen.
Table 47
Network Settings > NAT > Port Triggering
LABEL DESCRIPTION
Add new rule Click this to create a new rule.
# This is the index number of the entry.
Status This field displays whether the port triggering rule is active or not. A yellow bulb
signifies that this rule is active. A gray bulb signifies that this rule is not active.
Service Name This field displays the name of the service used by this rule.
WAN Interface This field shows the WAN interface through which the service is forwarded.
Trigger Port The trigger port is a port (or a range of ports) that causes (or triggers) the VDSL
Router to record the IP address of the LAN computer that sent the traffic to a
server on the WAN.
Start This is the first port number that identifies a service.
End This is the last port number that identifies a service.
Trigger Proto. This is the trigger transport layer protocol.