Chapter 11 Network Address Translation (NAT)
NBG-417N User’s Guide
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2Port 7070 is a “trigger” port and causes the NBG-417N to record Jane’s computer
IP address. The NBG-417N associates Jane's computer IP address with the
"incoming" port range of 6970-7170.
3The Real Audio server responds using a port number ranging between 6970-7170.
4The NBG-417N forwards the traffic to Jane’s computer IP address.
5Only Jane can connect to the Real Audio server until the connection is closed or
times out. The NBG-417N 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
1Trigger events only happen on data that is going coming from inside the NBG-
417N and going to the outside.
2If 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.