ZyXEL Communications NBG-417N manual Two Points To Remember About Trigger Ports, 128

Chapter 11 Network Address Translation (NAT)

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.

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NBG-417N User’s Guide