Polycom ViewStation EX User Manual page 206

Appendix A
ViewStation User Guide
4. Enter the NAT's external IP address into the NAT outside
(WAN) address field.
Write down the Fixed TCP and UDP port numbers displayed on
this screen. These numbers typically are the following default
numbers:
TCP: 3230 to 3231
UDP: 3230 to 3235
5. In your NAT, reset the fixed ports from step 4 to be permanently
open, and redirect them to the IP address of your ViewStation.
6. To accept incoming calls, open and redirect port 1720 to the IP
address of your ViewStation.
190
Network Address Translation
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