Two Points To Remember About Trigger Ports - ZyXEL Communications LTE3301 Series User Manual

Trigger Port Forwarding Process: Example
Fig ure 61
Ja ne 's com put e r
Jane requests a file from the Real Audio server (port 7070).
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Port 7070 is a "trigger" port and causes the LTE3301 to record Jane's computer IP address. The LTE3301
2
associates Jane's computer IP address with the "incoming" port range of 6970-7170.
The Real Audio server responds using a port number ranging between 6970-7170.
3
The LTE3301 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 LTE3301
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times out in three minutes with UDP (User Datagram Protocol), or two hours with TCP/IP (Transfer Control
Protocol/Internet Protocol).
10.6.5 T wo Po ints T o Re m e m b e r Ab o ut T rig g e r Po rts
Trigger events only happen on data that is coming from inside the LTE3301 and going to the outside.
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If an application needs a continuous data stream, that port (range) will be tied up so that another
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computer on the LAN can't trigger it.
Chapter 10 NAT
LTE3301 Series User's Guide
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Re a l Audio Se r ve r
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