Groups of DID can be created so the Customer can choose inbound numbers via the Customer UI. The creation of DID groups does not link them with any customer. One of the settings in the Customer Account is the possibility of offering numbers from a DID Group.

See List DID Destination to map DID numbers with Customers

The option import DIDX allows you to import numbers from www.didx.net

You need to setup your DIDX account via the System Settings > Global List Config->webui

DIDX ID  	                 didx_id  	 
DIDX PASS 	         didx_pass 	 
DIDX MIN RATING 	 didx_min_rating 	 
DIDX RING TO 	         didx_ring_to