D-Link Broadband DSL-254B User Manual page 49

Section 3 – Configuration
You can configure the service settings on this window by clicking the
Select a Service radio button and then using the drop-down list to choose
an existing service, or by clicking the Custom Server radio button and
entering your own Application Rule in the field provided.
Click Save/Apply when you are finished with the virtual server
configuration.
D-Link DSL-2542B User Manual 49