Follow the instructions below to get a list of available numbers / DIDs:
Go to the PBX page of your dashmanager.
Go to the Inventory page.
Under the Phone Numbers tab click on the Filters button.
In the Phone Numbers Filters dialog choose Available Number in the drop-down menu for the Treatment field.
Click on Filter.
The results will show the DIDs that are available for use, not currently routed to a user.
You can download a copy of the results by clicking on the Export button.