D-Link DWR-923 User Manual page 49

Advanced NAT  UPnP Port Mapping
For devices that support Universal Plug and Play (UPnP), enabling the
UPnP Port Mapping function will allow automatic port forwarding that
helps your UPnP devices communicate with the Internet.
UPnP Settings: Check the box and click Apply to enable UPnP port
mapping function.
UPnP Portmap Table: UPnP devices that are applied with the UPnP
port mapping function will be listed in this chart.
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