Zhone 2000 用户手册

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The size of the NAT port range defines the number of simultaneous 
connections permitted. A small port range limits the number of 
connections. Since the range that you assign must be outside the range of 
assigned ports, do not set port ranges under 5,000.

Under normal circumstances, the port range default setting is adequate. 
However, if you interact with products including multiple-player IP games 
or video conferencing, you need to configure the port range setting.

To multiplex several connections to a single destination, the IAD assigns 
all packets unique port numbers. Each IP packet starts with a header that 
contain the source and destination addresses, as well as two port 
numbers. The addresses specify the two routers at each end, while the 
two port numbers ensure the unique identification of each router pair.

When the IAD sends TCP or UDP connection from a local port to an 
Internet port, it changes the sent IP address to the address of the Internet 
port. Similarly, it changes the TCP or UDP connection port number to a 
unique value within the NAT port range.

You can display the NAT settings with the Display NAT Local Server Table 
command. 

To configure the NAT port range:

1. Type R on the NAT Configuration menu to select the Configure NAT 

Port Range.

2. The IAD displays the low end port range prompt:

Enter Low End of NAT Port Range (5000..65534): 
(50000)

Type the low end value and press Enter.

3. The IAD displays the high end port range prompt:

Enter High End of NAT Port Range (50000..65534): 
(50000)

Type the high end value and press Enter.

4. The IAD saves the configuration and displays the NAT Configuration 

menu.

5. Continue with other NAT configuration tasks, or press Escape to return 

to the Main menu.

6. Reset the IAD (page

) when you finish configuring NAT.

 

Ensure that the NAT port range does not include any ports 
that use applications such as HTTP, TFTP and so on.