ZyXEL Communications Corporation EMG2926Q10A Manuel D’Utilisation

Page de 206
Chapter 14 NAT
EMG2926-Q10A User’s Guide
128
2
Port 7070 is a “trigger” port and causes the EMG2926-Q10A to record Jane’s computer IP address. 
The EMG2926-Q10A 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 EMG2926-Q10A 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 
EMG2926-Q10A times out in three minutes with UDP (User Datagram Protocol), or two hours with 
TCP/IP (Transfer Control Protocol/Internet Protocol). 
14.5.5  Two Points To Remember About Trigger Ports
1
Trigger events only happen on data that is coming from inside the EMG2926-Q10A 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.