Dinstar UC200 Pro - Page 12

You can also create Trunk/FXO. It is an alternative to support calls go through
or from PSTN.
FXO
You can set up ISDN PRI/SS7 connections via digital E1/T1 ports. Please be
sure that the E1/T1 physical connection is well connected, and PRI status is in
up and active status before configuring the call routing.