Chapter 10 NAT
LTE5366 Series User’s Guide
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manner. This way you do not need to configure a new IP address each time you want a different LAN
computer to use the application.
10.6.4 Trigger Port Forwarding Example
The following is an example of trigger port forwarding.
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 LTE5366 to record Jane’s computer IP address. The LTE5366
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 LTE5366 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 LTE5366
times out in three minutes with UDP (User Datagram Protocol), or two hours with TCP/IP (Transfer Control
Protocol/Internet Protocol).
10.6.5 Two Points To Remember About Trigger Ports
1
Trigger events only happen on data that is coming from inside the LTE5366 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.
