You can add new rules that allow for specialized routing based on information sent by the provider or deduced from the channel group. Typically a Single DID Route is used to direct incoming calls, from a specific phone number, to a specific extension.
Go to Setup -> Call Routing -> Incoming Calls.
Select the Create Single DID Route button.
Complete the fields:
Rule name
Note (optional)
Incoming DID to match (A phone number only, without special characters)
Extension to route (Extension that will receive the call)
Save your new settings
You may now call to confirm your new DID route is working as expected.