1. For DID numbers management, Sippy has a separate page in main menu:

2. Click "Add" button to add a new DID number.

3. Set your DID number in fields "DID" and "Incoming DID/CLD":

Where "Incoming DID/CLD", Sippy Softswitch uses for authentication of incoming call by CLD.

Then click "Save&Close" button.

As an additional measure Sippy recommends to use Vendor & Connection fields in the "Authentication Rules" section. This is for authentication of incoming traffic only from some particular Remote IP (IP from which DID provider's traffic will arrive to Sippy).

2. As an additional security measure Sippy recommends to authentication the incoming traffic by remote IP too. To achieve this, you need to open "Vendors" menu and add a new Vendor & Connection with IP of DID provider from which traffic will arrive to Sippy:

Then open again a "DID Pool" page -> properties of some DID and set in the "Authentication Rules" section an appropriate "Vendor/Connection":

3. Then click on "Assigned to" and assign your DID number to some account or IVR application. In result incoming call to the DID number system will route to some particular account or IVR application:

4. If your call should be routed from the "DID" entry to the registered account, please check if it was set in the "Incoming routing" of the assigned to the DID account: