About Directory Number Routing

Directory Number is a 10 digit telephone number which is divided into three parts:

NPA: The first three digits of a telephone number known as Numbering Plan Area (NPA) code.
NXX: The second three digits of a telephone number known as Central Office code is also known as prefix.
Line: The last four digits of a telephone number.

Using Oracle Communications Design Studio, DN can be configured on atomic actions in a cartridge. See ASAP System Administrator's Guide.