Draytek Vigor2500V Manual page 53

As stated above, after you click one index number, say index No. 1, in the
above figure, you will see the following setup page for the entry with index No.
1. Further, each entry (local host) can specify 10 port-ranges for varied
services. The computer with private IP address of 192.168.1.22 will be the
host for the specified incoming packet of named as "streaming". Following
example, the UDP port ranges from 6835 to 6850.
Enable Open Ports: Check to enable the Open Port function for this entry.
Comment: Specify the name for the defined network service.
Local Computer: Enter the private IP address of the local host.
Choose PC: Click this button and, subsequently, a window having a list of
private IP addresses of local hosts will automatically pop up.
Select one appropriate IP address of the local host in the list.
Protocol: Specify the transport layer protocol. It could be TCP, UDP, or
NONE for selection.
NAT
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